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TECHNICAL FIELD
[0001] The present invention relates to a computer implemented simulation system available to a wide range of researchers.
BACKGROUND ART
[0002] Researchers in various scientific or engineering fields often would like to discuss with colleagues modeling schemes and results of a new simulation model for scientific or engineering projects. Traditionally, these discussions are done separately. To have discussions with sharing models and simulation data, the researchers need to follow several steps. For example, these steps include: sharing a model that is under development with colleagues by email; commenting on it and revising the model; creating executable model off-line and performing a simulation in a local machine; and after the simulation, again sharing the simulation results with colleagues by e-mail or a file-sharing service for further discussion. If the number of colleagues is large, the process can be burdensome and time consuming.
[0003] Further, even if a researcher wishes to perform high performance simulation with parallel computing, the researcher is not always in the environment where high performance computers (HPCs) are available. For example, if an institute where the researcher belongs does not have HPCs, it is not easy for the researcher to gain access to HPCs. Or even if the institute has an HPC, if the researcher is outside of the firewall, the access is usually restricted. Simulators must be able to have a direct access to computing resources. Therefore, users need to install the simulators on the computing resources directly. Since HPCs typically limit the access from outside by firewalls, it is difficult or impossible for users to access to the simulators from outside of the firewalls.
[0004] Further, simulations of models are typically done by saving the executable binary code of the model in a local storage area of computing resources, such as a desktop machine or cluster machine, and by executing the binary code on that machine. A model developer needs to write program codes for algorithm of numerical computation as well as the scientific logic of the model. Hence, for researchers, it is difficult to concentrate only on building the scientifically essential logic of the modeling target phenomena.
[0005] Since the model size is getting larger recently, parallel computation for high-performance computing on such as cluster machines is required. In this case, it is necessary for a researcher to implement specific algorithms using MPI (Message Passing Interface) or some other technologies to parallelize the processes. It is a time consuming task to implement such a program with parallel computing algorithm, because it requires high-level programming techniques.
[0006] Moreover, the parallelization efficiency is dependent on the hardware configuration of the cluster machines. For example, if a program was tuned on cluster A, the same program may not be always effective on cluster B. Hence a researcher needs to spend more time for optimization of the program depending on the hardware, which is again not scientifically essential.
[0007] In case of a large simulation, usually a simulation performer wants to know the progress of the simulation. It would be helpful show the percentage of the simulation progress, or to show graphs of time series data of the simulated variables. To do this, the model developer would need to spend additional time to implement such tricks in the program.
[0008] In addition, it may be necessary to modify the value of variables during a simulation, or interrupt the simulation in its midway, depending on the outcome of the simulation. Implementation of these tasks is time consuming and imposes additional burden besides the scientific issue to researchers.
[0009] SBSI (http://www.sbsi.ed.ac.uk/index.html) provides simulation service using their HPC. However the system is not reachable from the outside of a firewall, and supports only SBML (System Biology Markup Language) format.
[0010] There exist several simulators receiving SBML and CellML formats files as input. None of them has a function to send data to Social Network Services or receive simulation models from Social Network or like services. Many of them are standalone simulators, so that users need to install them to the computing resources directly, thereby being subject to the similar problems as discussed above.
SUMMARY OF INVENTION
Technical Problem
[0011] Accordingly, the present invention is directed to a simulation system that substantially obviates one or more of the above-discussed and other problems due to limitations and disadvantages of the related art.
[0012] An object of the present invention is to provide a simulation system accessible by a wide range of researches with improved convenience.
Solution to Problem
[0013] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, in one aspect, the present invention provides a simulation system, including an interface component implemented in one or more of computers, the interface component generating a simulation job and registering the simulation job in a database, at least a portion of the interface component being placed outside of a firewall and connected to a public or shared network that has less restrictive access than networks inside the firewall to receive a model for simulation from outside of the firewall; a job control component implemented in one or more of computers, the job control component accessing said database to retrieve the simulation job and scheduling the simulation job for execution; and a simulation execution component implemented in one or more of computers, the simulation execution component receiving the simulation job from the job control component, creating executable codes for numerical and parallel computing algorithms and distributing computing processes to multiple computers to execute the simulation job, wherein, the job control component receives simulation progress information from the simulation execution job, registers the simulation progress information in the database, and sends the simulation progress information to the interface component, wherein the simulation execution component sends the simulation progress information to the job control component, temporarily stores data created by the simulation job, and sends simulation results to the interface component, and wherein the interface component displays the simulation progress information and the simulation results on a website hosted by the interface component or sends messages to users to inform the users of the simulation progress information and the simulation results.
[0014] In another aspect, the present invention provides a simulation system having the above-referenced features, wherein the interface component is configured to receive a simulation model from a user located outside said firewall and generates the simulation job in accordance with the simulation model.
[0015] In another aspect, the present invention provides a simulation system having the above-referenced features, wherein the interface component is connected to a public network including a social networking host, and receives the simulation model submitted through a social network website hosted by the social networking host.
[0016] In another aspect, the present invention provides a simulation system having the above-referenced features, wherein the interface component is configured to receive a simulation model from any one or more of Facebook Group, circles of Google+, Google drive, Dropbox, and model databases published on the Internet.
[0017] In another aspect, the present invention provides a simulation system having the above-referenced features, wherein the simulation model is expressed in any one or more of SBML (System Biology Markup Language), CellML, and PHML (Physiological Hierarchy Markup Language).
[0018] In another aspect, the present invention provides a simulation system having the above-referenced features, wherein the interface component displays graphs of the simulation results on the website, and sends the simulation results to a social networking service to display the simulation results in a social network website.
[0019] In another aspect, the present invention provides a simulation system having the above-referenced features, wherein the job control component and the simulation execution component are implemented in the same set of one or more of the computer inside the firewall.
[0020] In another aspect, the present invention provides a simulation system having the above-referenced features and further comprising one or more of additional simulation execution components, wherein when a plurality of simulation jobs are handled, the job control components assign the simulation jobs to simulation execution components, respectively, and wherein in at least some of the simulation execution components, a plurality of computers are connected through a real-time communication network to perform distribute computing over the network to execute the simulation job.
[0021] In another aspect, the present invention provides a simulation system having the above-referenced features, wherein the real-time communication network is the Internet.
[0022] In another aspect, the present invention provides a simulation system having the above-referenced features, wherein said firewall is placed between the interface component and the job control component.
[0023] In another aspect, the present invention provides a simulation system that has the above-referenced features and that further includes a client computer connected to the interface component, the client computer being outside of the firewall and installed with a model building software to generate a model for simulation written in any one or combination of SBML (System Biology Markup Language), CellML, and PHML (Physiological Hierarchy Markup Language), the client computer submitting the model for simulation to the interface component.
Advantageous Effects of Invention
[0024] Additional or separate features and advantages of the invention will be set forth in the descriptions that follow and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
[0025] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0026] FIG. 1 is a diagram schematically illustrating functional aspects of a simulation system according to an embodiment of the present invention.
[0027] FIG. 2 schematically illustrates the architecture of a simulation system according to an embodiment of the present invention.
[0028] FIG. 3 schematically illustrates an example of a physical configuration of a simulation system according to an embodiment of the present invention.
[0029] FIG. 4 is an example of a website interface screen according to an embodiment of the present invention.
[0030] FIG. 5 is an example of a website interface screen according to an embodiment of the present invention.
[0031] FIG. 6 is an example of a website interface screen according to an embodiment of the present invention, showing a simulation result.
[0032] FIG. 7 schematically illustrates a model building procedure in constructing a simulation model in an embodiment of the present invention.
[0033] FIG. 8 schematically shows examples of screen shots of a software program implementing the model building procedure in an embodiment of the present invention.
[0034] FIG. 9 schematically shows examples of a website interface in a simulation system according to an embodiment of the present invention.
[0035] FIG. 10 schematically illustrates an example of a physical configuration of a simulation system according to an embodiment of the present invention.
[0036] FIG. 11 schematically illustrates an example of the architecture of a simulation system according to an embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0037] The present invention provides, in some embodiments, a procedure to seamlessly link the activities, such as scientific discussion, sharing models of physiological functions, performing simulations, and sharing simulation results, within a social community. It also relates to a method to run a high performance simulation ubiquitously.
[0038] In some embodiments of the present invention, the primary aspects of the system are the following.
[0039] 1. Linkage between high performance simulation service provided in the internet and existing social network services (SNS), such as Facebook, Google+, or a propriety social network-type interface seamlessly.
[0040] 2. The system architecture is suitable for being ported to or implemented in any type of high performance computers. The invented system receives model files written in languages, PHML (Physiological Hierarchy Markup Language), SBML and CellML. Information that is required for numerical computation, such as mathematical formulae representing the dynamics of the physiological phenomena, physical units, is described in the model file. However, the algorithms for numerical calculation and parallel computing, etc., need not be included, because the system handles all of these algorithms including automatic parallelization of processes.
[0041] FIG. 1 is a diagram schematically illustrating functional aspects of a simulation system according to an embodiment of the present invention. The simulation system can receive models 101 through network directly from Facebook Group, circles of Google+, Google drive, Dropbox or model databases published on the net (such as physiome.jp) or from a proprietary social network-like interface (Box 102 ). Alternatively or in addition, an application can upload a model directly to the system using APIs (Application Programming Interface) provided by the system 103 . By this feature, users can try a simulation of a model on which they discuss at a Facebook group or Google+ circle, for example, anytime.
[0042] The invented system automatically generates an executable code based on the inputted model file for a simulation. Algorithms to parallelize the processes are incorporated into the executable code automatically, and simulation is performed by parallel computation (Box 104 ).
[0043] Function and interface to change the values of parameters, abort the simulation, and to interrupt the simulation at any time during simulation are also implemented in the system. Users do not need to implement these functions.
[0044] The simulation results 108 are stored on the server at first. The progress report 105 / 106 (such as percentage of completion) is also generated automatically. The invented system notifies users the progress information by sending messages 107 via e-mail, Facebook message, Facebook Group post, Twitter, and Google+ message with a frequency that users defined.
[0045] Time series data generated by the simulation can be large in size. In such a case, time series data 109 and graph images 110 may be sent to storage media 111 , such as user's local machine, Dropbox, and Google drive. Graph images may be sent to a Facebook group, a Google+ circle or Evernote 112 as well, so that users can continue to discuss based on the simulation result on the SNS (social network service) or on the proprietary social network type interface.
[0046] FIG. 2 schematically illustrates the architecture of a simulation system according to an embodiment of the present invention. In this embodiment, the simulation system includes an interface component 201 , a simulation job control component 202 , and a simulation execution component 203 . Hereinafter a simulation job is simply referred to as a job.
[0047] The interface component 201 generates a job and registers the job to a database. The interface component does not directly send jobs to the job control component (although the arrow in FIG. 2 indicate a flow of “Job” from the interface component 201 to the job control component 202 , the job is indirectly forwarded through the database), so that the interface component 201 can be located outside of the firewall surrounding the computing resources. The interface component 201 also receives the simulation progress information from the job control component 202 , and displays the information on its website accessible by the browser or sends messages via e-mail, twitter, Facebook message, or Facebook group 102 a, to inform users of the progress information. In addition, it displays graphs of simulation results on the website, and sends the simulation results to Facebook group, Google drive, Dropbox, Evernote, Google+ circle 102 c.
[0048] The job control component 202 takes the job from the interface component 201 by accessing to the database. It also adjusts the timing to send the job to the simulation execution component 203 , and sends the job to the simulation execution component 203 at the appropriate time. In addition, it receives the simulation progress information from the simulation execution component 203 , and registers it in the database. Moreover, it sends the simulation progress and job status to the interface component 201 .
[0049] The simulation execution component 203 receives a job from the job control component 202 , creates executable code including parallel computing algorithms, and distributes the processes to multiple nodes, and executes a simulation automatically (Box 204 ). Moreover, it sends simulation progress information to the job control component 202 . Data created by a simulation is stored in the simulation execution component 203 temporarily. After finishing the simulation, the result file is sent to users ( 102 a to 102 c ), such as user's local machine, Dropbox, Google drive, via the interface component 201 .
[0050] Because the system is composed of three components, as described above, the system can solve the problem on availability of the simulator system from outside of a firewall.
[0051] The simulation execution component 203 has direct access to computing resources such as PC clusters, since HPCs typically limit the access from outside by firewalls. As explained above, traditionally, a simulator was built as all-in-one single component application, and therefore, users needed to install the simulators on the computing resources directly. Also, it was difficult or impossible for users to access to simulators from outside of the firewalls.
[0052] However, because the system of the present embodiment is composed of three components, as explained above, it is possible to locate the interface component at DMZ (DeMilitarized Zone: a physical or logical sub-network that contains and exposes an organization's external services to a larger untrusted network, usually the Internet) so that a user can access the interface component from outside the firewall (the Internet), and can submit a simulation job to the system. Then, the job control component 202 , which may be placed inside the firewall, can take the job from the interface component via TCP connection.
[0053] Furthermore, it is possible to perform a series of simulations by the simulation execution component 203 . Moreover, because the job control component 202 can be installed in other places than computing resources, it is possible to operate the system more flexibly.
[0054] FIG. 3 schematically illustrates an example of a physical configuration of a simulation system according to an embodiment of the present invention. Computer C 1 on a firewall FW represents the interface component 201 , and computer C 2 inside the firewall correspond to the job control component 202 and the simulation execution component 203 . SPs indicate simulation processes distributed by the simulation execution component 203 . As shown in FIG. 3 , users 302 outside of the Firewall FW can use their local personal computers C 4 to access the interface component (hosted by the computer C 1 ) through the Internet 301 . As discussed above, Social Networking Services (SNSs) or other like interfaces may be used via the Internet in submitting simulation models to the computer C 1 . With this configuration, not only users 303 inside of the firewall, but also users 302 outside of the firewall FW have access to computing resources. Here, D 1 in FIG. 3 indicates the database in which the simulation job is stored as explained above.
[0055] FIG. 4 is an example of a website interface screen according to an embodiment of the present invention. The computer C 1 acting as the interface component 201 can host a website for authorized users and can receive and show information regarding the simulation. FIG. 4 shows an example of interface screen when the simulation is ongoing. As shown in FIG. 4 , information and the status on requested simulation jobs may be glanced at once.
[0056] FIG. 5 shows an example of the website interface screen of the website when the simulation job is completed. The simulation status is now “Completed” and the progress bar shows 100%.
[0057] FIG. 6 is an example of the website interface screen showing the simulation results. As shown in this figure, the user can download the result to a local computer or can transfer the file to Dropbox.
[0058] As described above, in some embodiments, PHML can be used to build a model for the simulation. Since the conventional simulators do not support PHML for simulation models, the embodiments described above have significant advantage in supporting PHML.
[0059] Other embodiments of the present invention that are particularly suitable for biological or like researches are described below.
[0060] In this aspect, the present invention provides a software framework to support modeling and performing simulations of multilevel physiological systems, which, in some embodiments, has been developed and expanded to support the cloud computing.
[0061] The framework is composed of two blocks; a local model designer (an actually developed version is named “PhysioDesigner™”) and a simulation system implementing some or all of the features of the simulation system embodiments described above. An actually developed version of the second part-the simulation system-is named “Flint™” or “Flint system,” and its expanded version, which supports cloud computing, as described below, is named “Flint K3™ system.” PhysioDesigner™ is an application providing a graphical user interface for assisting users in multilevel modeling of physiological functions and a terminal interface for script-based model building. Models built on PhysioDesigner™ are written in PHML (the physiological hierarchy markup language). Flint™ is a standalone simulator, supporting MPI for parallel computing on a proper system environment. Based on the standalone application, Flint K3™ system supporting cloud computing has been developed, which provides a solution for portable high performance simulation. At the website of Flint K3™, users can upload models described in PHML. In addition, PhysioDesigner™ and other applications can submit simulation jobs to Flint K3™ directly at online.
[0062] Below, the background in developing these embodiments of the present invention and some of specific features of actually built application/systems: PhysioDesigner™, and Flint™, Flint K3™ will be described as embodiments of the present invention. However, the present invention is not limited to any of these specific features of the developed application/systems unless these features are recited in claims appended hereto.
[0063] In past decades, based on a large amount of data provided by the reductionism science, modeling-based science in systems biology and integrated physiology has been progressing rapidly. In these fields, models are getting bigger in size and more complicated and detailed in structure. It is almost impossible to build such models without inter-research-group collaborations, not only between so-called ‘wet’ and ‘dry’ research groups but also ‘dry’ and ‘dry’ research groups. For promoting effective collaboration, building large-scale models and performing CPU intensive simulations, it is very important to develop tools to support such activities.
[0064] Features described below, which are implemented in PhysioDesigner™, are aiming at providing a common integrated development environment for users who want to create models of multilevel physiological systems. Users can describe dynamics of a state of a targeted physiological system with hierarchically structured mathematical formulae using graphical user interface. The models built on PhysioDesigner™ are written in PHML (Physiological Hierarchy Markup Language), which is an XML based specification designed to represent explicitly physiological hierarchical functions. PhysioDesigner™ has been made available to the public (http://physiodesigner.org).
[0065] Besides the building models, performing simulations is the important counterpart. The simulation systems described above as embodiments of the present invention, which are implemented in Flint™, may be an interpreter type simulator that can work with PhysioDesigner™. As described above, the simulation system can be configured to parse PHML, compile internally and run a simulation. Flint™ can use multiple cores for computation-intensive simulations using MPI if the system has the MPI environment. This feature could be crucial because of the growth of the models in size. However, unfortunately, such high performance PC clusters with many CPUs are not always available. Flint K3™ service, which is Flint™ that can work on computer clouds has been developed to meet these needs. Flint K3™ system is equipped with a portal website for job managing. Users can submit simulation jobs on the site. Besides, PhysioDesigner™ can send a simulation jobs directly to the Flint K3™ via the Internet.
[0066] Model Building Software/System
[0067] A model building software is provided to assist users build models for simulations. PhysioDesigner™ is an application software that enables users to edit hierarchical multi-layer models of living systems. The application has been made available at http://physiodesigner.org. It has previously been developed as insilicoIDE (http://physiome.jp), and according to the recent progress in development, the application was renamed to PhysioDesigner™ as its next generation.
[0068] Embodiments of the present invention, if and when coupled with a model building software, may be configured to implement some or all of the features of the PhysioDesigner™, which will be described herein.
[0069] Models built on PhysioDesigner™ are written in PHML format, which is an XML based specification to describe hierarchy of systems in comprehensive biological models. PHML is a successor language of ISML (http://physiome.jp), which has been developed since 2007.
[0070] In PHML, each of biological and physiological elements involved in a model is called a module as summarized in FIG. 7 , and structural and functional relationships among modules are defined by edges. Groups of modules can be defined as a module. By this recursive definition of the module, a hierarchical structure of the physiological systems is expressed in a model. Each module is quantitatively characterized by several physical quantities, such as, states defining the system's dynamics, and variable and static parameters. Definition of the dynamics such as ordinary/partial differential equations, or functions of physical quantities are explicitly described by mathematical equations.
[0071] Definition of a functional relationship among modules are represented by edges (functional edges) linking an out-port of a module to an in-port of another module, which carries numerical information defined as physical-quantities. A module receives the information can utilize it in equations defined in the module ( FIG. 7 ).
[0072] Logical structures among modules can be also defined by edges (called structural edges). A logical structure represents a kind of ontology like relationships among modules such as “has a” relationship. In terms of physiology, it corresponds to “constitute” (e.g. many cardiomyocyte constitute a heart), “include” (a cell membrane includes organelles) and so on.
[0073] FIG. 7 shows an exemplary schema of PHML to represent modules, physical quantities, and edges. In Module 1 , there are two physical-quantities a and y are defined. a is a static parameter (i.e., constant) and y is a state used to define a ordinary differential equation. y is associated to an out-port to export its value, which is received by a physical quantity y in Module 2 through a functional edge and an in-port. By this association between y in Module 1 and y in Module 2 , the value of y defined in Module 1 is used in the equation of x in Module 2 . Module 3 and 4 are located at a sublayer of Module 2 .
[0074] The application provides graphical user interface to set all configurations that can be described by PHML. See FIG. 8 . FIG. 8 is a screen shot of some of the screens in the user display of the application. As schematically shown in FIG. 8 , the application graphically shows a model in two ways. One is a tree diagram, and the other is a nesting diagram. The main window also contains tables of physical-quantities and ports of the selected module, and a component list of modules. In addition, there is a XML viewer and PhysioTerminal on which users can execute commands based on Python and PhysioDesigner™ APIs.
[0075] In addition, the application provides APIs (Application Programming Interfaces) written in Python. Using the APIs, a user can fully deal with models on a terminal (or console) with Python shell without using GUI.
[0076] In some embodiments, a multilevel modeling can be performed by SBML-PHML hybrid modeling. SBML (the systems biology markup language) is an XML format for computer models of biological processes, such as metabolism, cell signaling, and more. PHML is designed to represent a functional network and hierarchical structure using its modular representation. Combining SBML and PHML, it is possible to extend the capability to construct models including multiple levels of physiological phenomena. In some embodiments, there may be provided a functionality to import a whole SBML model in a module of PHML. Then the module can represent the sub-cellular phenomena that are modeled by the SBML model. By linking the module with the SBML model to other modules by functional and structural edges, the SBML model eventually can be embedded in a PHML module network effectively in the senses of both structural and functional relationships. There is an import section within a module section in PHML specification to describe a whole SBML model. Practically not only SBML but also any model format can be embedded in a module.
[0077] In SBML, there are “species” and “parameters” to represent quantitative attributes of biochemical entities. At a module including a SBML model, it is possible to define physical quantities associated to species or parameters to set or get numerical values. Physical quantities in PHML part can utilize the numerical information defined in the SBML model by “get” definition acting as an one-way bridge from the SBML part to the PHML part. Similarly but with opposite direction, “set” definition can quantitatively affect to the SBML part from PHML part by overriding the original definition of species or parameters in the SBML model without modifying the SBML model itself. By the definitions of getter and setter, the SBML model is effectively involved in the model.
[0078] Simulation Systems
[0079] In this disclosure, a simulation system implementing some or all of the features of the simulation system described above may be used in connection with the model building software described above. Some embodiments of the present invention may be configured to implement some or all of the features Flint™ and/or Flint™ system, described herein.
[0080] In the present invention, the tasks for model construction and for simulation are separated. Users can focus on the structure and logic for building a model without being troubled by implementation of algorithms for numerical calculations because these tasks are handled by the simulation system that receives models built by the model building software.
[0081] FIG. 9 shows exemplary screen shots of the user-interface on a webpage accessible by authorized users. On the top window of Flint™, users can select the numerical integration algorithm (for example, Euler method or 4-th order Runge-Kutta method), set the simulation duration, and time step with unit of time and sampling interval to record the values in a data file (A in FIG. 9 ). Before running a simulation, it is possible to select physical quantities that are recorded in the data file (B in FIG. 9 ). By these settings (sampling interval and selection of physical quantities), size of data file can be made smaller. C in FIG. 9 shows graphical outputs. Flint™ can show intermediate results by graphs during a simulation (C and D in FIG. 9 ). Graphs may be updated in substantially real time as the simulation progresses. This feature is convenient for users to check the current status of the simulation when they want to perform simulations that may take a long time. The graph plotter implemented on Flint™ can export the graph into an image files such as PDF, PNG, etc. Flint™ also supports external graph plotter such as gnuplot to create a more proper figure for publication or presentation.
[0082] The simulation system may be configured to perform simulations of models written in SBML as well as PHML using SOSlib. The system may be configured to parse and perform simulation of SBML-PHML hybrid models. This is an effective way to model and simulate models of spatiotemporal multi-level physiological systems as mentioned above. At first Flint™ extracts all equations and defines relationships among equations. Then it compiles internally those equations simultaneously. Flint™ can deal with equations with ODEs (Ordinary Differential Equations) and DDEs (Delay differential equations), which can include stochastic terms.
[0083] The simulation system may be configured to support parallel computing using MPI (for example, it has been implemented in Flint™ with OpenMPI 1.4 or later). The simulation system automatically divides a simulation over multiple CPUs (processors). This is one of advantages for users to use this platform, because if users want to adopt a parallel computing on a multi-core or PC-cluster environment, usually users are required to learn specific techniques additionally to develop a simulator which can perform parallel computing. This is usually a very time-consuming task.
[0084] For the development of cloud supporting feature of the simulation system of the embodiments of the present invention, a clear client-server architecture has been introduced to improve its portability.
[0085] In the case of Flint™, the server part is implemented as a program called “isbus.” A client software sends messages to isbus in order to request an execution of subprograms. Each of sub programs plays a specific role like parsing and inspecting a model, etc. Flint™ provides a GUI client implemented in Java. The same function may be implemented as a web application, as described below. When a client is going to run a simulation of a model, the client at first packs a request to start simulation of the model with parameters and sends it to dedicated TCP port of isbus. Then isbus reads the message, launches the program “isrun” which runs simulation processes for the model, packs a response and sends it back to the client. Notably packing messages is defined in a programming language in a neutral way, thus there are libraries of C++/Java/Python to handle the format. In the course of a simulation, simulation processes send the progress information to the client asynchronously. The client can either receive or ignore such information.
[0086] Simulation System with Cloud Computing
[0087] Since the size of models is getting larger and larger nowadays, simulation systems that work on high performance computers are demanded. To meet this demand, the simulation system that implement some or all of the features described above and that can work on cloud computing has been developed. The system so developed is named Flint K3™ (Knit Knowledge Knack) (referred to K3 sometime hereinafter). With this system, users of PhysioDesigner™ (or users in other model building environments) can immediately send simulation jobs to high performance cloud computing environment even if users do not have any accesses to high performance computers. K3 has been developed with “edubaseCloud” (http://edubase.jp/cloud), which is an open source based computer cloud for education of cloud engineering developed in National Institute of Informatics (NII). For development and preliminary test-run of Flint K3™, 64 cores on the cloud are assigned.
[0088] K3 is composed of two types of servers as shown in FIG. 10 . One is an interface server (IFS), which receives job requests from users and manages the jobs, implemented in computer C 5 . Simulation jobs are sent from IFS to simulation servers (SS) implemented in respective computers C 7 and C 8 in the clouds 1001 , 1002 , respectively. SSs evoke a computation program (CP) in every node assigned for the simulation. CPs perform numerical computation of the model in parallel having communications among them.
[0089] In the architecture shown in FIG. 10 , it seems that IFS may become a bottleneck of traffic. To avoid this issue, the traffic scalability may be ensured at IFS by several ways. One way is to put a kind of gateway on each cloud, so that the part of functions of IFS can be taken over by the gateways. Detailed communications are done between the gateway and SSs, and only necessary compact information is interchanged between IFS and the gateways. Alternatively or in addition, multiple clones of the IFS may be provided for the load balancing with a reverse proxy server. Then, the system can support secure single sign-on and distribute the loads to multiple IFSs at the same time.
[0090] In this embodiment, there are three ways for users to submit simulations jobs to Flint K3™. One way is to visit the K3 IFS on a web browser. Users can upload models and configure simulation parameters for submitting simulation jobs at the site by accessing the website hosted by the IFS through their respective computers C 6 ( FIG. 10 ). The second way is to utilize a linkage between K3 and Model databases at open domain ( FIG. 10 ). Presently, there is PHML model database at Physiome.jp (http://www.physiome.jp/modeldb/index1.php) and SBML model database at several sites such as Payao database (http://celldesigner.org/payao/index.html) and BioModels in EMBL-EBI (http://www.ebi.ac.uk/biomodels-main/). Users can provide a model ID defined in each database to K3 IFS. Then K3 IFS accesses the database and downloads the model directly from the model database. Once such linkages among database and simulation server are built, users can easily check the dynamics of a model in database. The third way is to use the REST APIs implemented on IFS, such as simulate(model, parameters), getStatus(job-id) and getProgress(job-id) so that applications such as PhysioDesigner™ can access to K3 directly, for example, to submit a simulation job and get the progress report of simulations.
[0091] FIG. 11 shows a schema of internal architecture of Flint K3™ system. User agents access to the Web Application on the interface server (IFS), and job related information such as a model file and parameters are stored in a storage. ISBUS takes the job information from the storage, and send a signal to launch a simulation to ISRUN in the simulation server (SS) at a cloud. ISRUN evokes several processes for computation in multiple nodes in the cloud. Progress information of simulation is fed back to the user through the web application on IFS.
[0092] Basically Flint K3™ has the same architecture with the standalone version of Flint™, except the following three major differences. First, K3 is enhanced on security because a user has to be authenticated and authorized in a session. IFS utilizes the OAuth standard. Users can login to IFS using accounts on Facebook, Twitter, Google and Dropbox. Second, since K3 works in a cloud environment with a large number of machines, each of which has physical multiple cores, K3 should find a desirable MPI-based virtual machine configuration in terms of usage of cores. That is, it is possible to map a big simulation process to one fat virtual machine with many physical cores, as well as to map several small processes to several thin virtual machines with a few cores. Third, possibly long-living simulation jobs should be controlled with efficient scheduling.
[0093] As described above, in some embodiments of the present invention, a software framework for multilevel modeling and simulation is developed. The software framework is composed of PhysioDesigner™ as a model builder, PHML as a model descriptive language, and Flint™ as a simulator, aiming at accelerating the progress of the integrated physiology and systems biology. As an extension of a standalone Flint™ application, Flint K3™ system is developed with cloud compatibility for providing easy access to the high performance computing environment. The software framework can be implemented by multiple computers as described above.
[0094] Due to the composition of K3 shown in FIG. 10 , it is possible to extend K3 to other clouds or computer clusters only by tuning simulation servers (SS in FIG. 10 ) to the new system's architecture for optimizing the performance.
[0095] There is yet another project called and Garuda platform, which aims at providing a fundamental technology to link software and knowledge in systems biology coherently. Flint™ and Flint K3™ services can be utilized not only from PhysioDesigner™, but also other tools which are in Garuda alliance (http://www.garuda-alliance.org/), such as CellDesigner. See FIG. 10 . This expands the scope of Flint™ related technologies and other embodiments of the present invention among systems biology and integrated physiology.
[0096] As in the embodiments described with reference FIGS. 1-6 above, the IFS hosted by computer C 5 ( FIG. 10 ) may be constructed by three different components: an interface component, a job control component, and a simulation execution component, each of which may be implemented by one or more computers. One or more of firewalls can be placed at appropriate locations such as between the interface components and the job control component so that the IFS can be configured to interact with one or more social network services or like services available or developed in a public network, such as the Internet, or in a private or semi-private network to receive the simulation job through such services.
[0097] It will be apparent to those skilled in the art that various modification and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover modifications and variations that come within the scope of the appended claims and their equivalents. In particular, it is explicitly contemplated that any part or whole of any two or more of the embodiments and their modifications described above can be combined and regarded within the scope of the present invention.
REFERENCE SIGNS LIST
[0098] 103 Simulation System
[0099] 201 Interface Component
[0100] 202 Simulation Job Control Component
[0101] 203 Simulation Execution Component
[0102] 301 INTERNET
[0103] 302 , 303 Users
[0104] 1001 , 1002 Clouds
[0105] C 1 , C 2 , C 3 , C 5 , C 7 , C 8 Computer
[0106] C 4 , C 6 Local Personal Computers
[0107] D 1 Database
[0108] FW Firewall | A simulation system includes an interface component connected to a public or shared network that has less restrictive access than networks inside the firewall, generating a simulation job and registering the simulation job in a database, a job control component accessing said database to retrieve the simulation job and scheduling the simulation job for execution, and a simulation execution component receiving the simulation job from the job control component, creating executable codes for numerical and parallel computing algorithms and distributing computing processes to multiple computers to execute the simulation job. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to automatic gain control circuits (AGC) and in particular AGC control of a single gate gallium arsenide (GaAs) FET amplifier.
2. Background Description
In digital radio systems, it is important to use modulation techniques which increase the number of bits per second per Hertz. As a result a number of multi-level modulation techniques have been devised for such use. One effect of these modulation techniques is to require a fairly high degree of linearity in the receiver input sections of such radio systems.
Because of spectrum utilization requirements, the frequencies most often available for digital radio systems are in the 11 GHz range and higher although some systems operate in the 6-8 GHz range. Such frequencies are adversely affected by rain. For example, it is well known that at 11 GHz rain attenuation is a major obstacle to the attainment of long path lengths between repeaters. A detailed study of this phenomena was made and was reported by S. H. Lin in an article, "Statistical Behavior of a Fading Signal", Bell System Technical Journal, Vol. 50, No. 10 December 1971, p. 3211. Because of the rain attenuation margin required as well as other factors, a dynamic operating range in the order of 60 dB appears to be realistic, particularly for the high rain areas. The dynamic range is defined as the difference between the maximum and minimum received signal levels (RSL) for a bit error rate (BER) of 1×10 -6 . The minimum (RSL) is determined by the noise figure (NF) of the receiver and the signal-to-noise ratio required for the modulation technique employed. The maximum (RSL) depends on the sensitivity of the modulated signal to non-linearity plus resultant AM to PM conversion which is caused by a high RSL. In order to use the available RF spectrum efficiently, higher order modulation schemes must be used. Signals containing amplitude modulation (16 QAM) are obviously more sensitive to amplitude compression than constant envelope signals such as are obtained in a 8 phase modulation technique (8 φ PSK). The following table shows the effects that the different dynamic ranges have on the maximum path length at 11 GHz:
______________________________________DynamicOperating Tampa, Fla. Wilmington, N.C. Portland, Ore.Range (km) (km) (km)______________________________________60 dB 10.4 11.3 2555 dB 8.9 9.6 21.350 dB 7.5 7.9 18.145 dB 6.4 6.9 15______________________________________
The sites selected represent the full range of expected conditions: (a) extreme rain rates (b) typical Eastern and Midwestern locations (c) few intense thunderstorms.
From the table above it can be seen that a dynamic range of 60 dB or more is highly desirable, because it determines the maximum useable hop length. Unfortunately this leads to a extremely high RSL for the system. For example, a 16 QAM system with a guaranteed threshold level of -70 dbm will have a maximum receive signal level of at least -10 dbm, a level at which the receiver input must still be linear.
A typical receiver input consists of an RF receive filter, low loss mixer and IF preamplifier with automatic gain control. Although such a receiver is not shown in detail, the elements 1, 2, 4, 6, 14 and 16 as shown in FIG. 1 would make up such a receiver input circuit. A receiver NF between 7 dB and 8 dB can be obtained with such a circuit if the IF preampliflier NF is kept below 1.5 dB. An IF preamplifier with voltage feedback, using a NEC NE64535 transistor and AGC after the input stage gives a typical noise figure of 1.2 dB. The overload characteristic of such a typical receiver input is shown in FIG. 3. The level of inter modulation products (2A-B) from two equal level signals f A and f B is used as a measure of linearity of the receiver input configuration. As a result of non-linearity, 2f A -f B , 2f B -f A , 3f A -2f B , 3f B -2f A , etc., intermodulation product signals appear at the output of the IF preampliflier. If the 2A-B product level is more than 40 dB below the A or B level, then the system can be considered linear enough for use with the digital modulation techniques currently employed.
The addition of a GaAs FET preamplifier will reduce the system NF to 5 dB, but if no AGC is used ahead of the mixer the overload of the IF premplifier will become worse, actually decreasing the dynamic range of the receiver. Additional RF preamplification could be employed, but this has the effect of overloading the mixer which also adversely affects the available dynamic operating range. A variable attenuator could be inserted between the RF preamplifier and the mixer providing an AGC technique. The insertion of the loss in the RF portion of the receiver would necessitate the use of a second stage of preamplification in order to obtain the required low overall noise figure (NF). But now the second stage of the preamplifier will overload. One way to overcome this problem is to provide a variable gain RF preamplifier.
SUMMARY OF THE INVENTION
A single GaAs FET is used as an RF preamplifier in the input section of a radio receiver and the gain of the GaAs FET is controlled by a direct current voltage (DC control signal) that is derived from and is proportional to the amplitude of the signal which appears at the output of a subsequent circuit which includes a fixed gain amplifier. This DC control signal is used to control the operating power applied to the RF preamplifier, thereby providing AGC action.
DESCRIPTION OF THE DRAWING (S)
FIG. 1 is a block diagram which illustrates the RF and IF sections of a radio receiver including the AGC circuit of the invention;
FIG. 2 is a schematic diagram which shows in detail a preferred embodiment of the AGC circuit of the invention;
FIG. 3 is a graph of a typical receiver characteristics illustrating the relationship between the RF input level and the amplitude of intermodulation products;
FIG. 4 is a graph illustrating the relationship of the RF Preamplifier gain Vs. Supply Voltage;
FIG. 5 is a schematic diagram which illustrates how the gain of the RF Preamplifier may be controlled by varying only the gate voltage; and
FIG. 6 is a graph which shows the overload performance of a complete receiver in which the invention is used.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, the environment in which the AGC circuit of the invention is designed to operate is illustrated. The radio frequency input from the antenna system is applied via path 1 to circulator 2, and thence to an RF filter 4, which limits the band width to the limits for the radio channel, and the band limited signal is passed to circulator 6, then via path 8 to the input of the RF preamplifier 12, which is a variable gain amplifier. The band limited amplifier signal is then applied to the RF to IF converter 14 before it is applied to the input of IF preamplifier 16 which provides an output signal on path 18.
The automatic gain control circuit is connected to path 18 at junction 20 and the IF signal is passed along path 22 to level control 24 and then through path 26 to power source control 28. Here the supply voltage to the RF preamplifier 12 is adjusted so as to control the gain of the RF preamplifier. Power to the radio frequency sections and to the IF section also is supplied via power source 28 as shown in FIG. 1. The automatic gain control circuit can be best understood by referring to the detailed schematic shown in FIG. 2.
The general configuration of the single gate GaAs FET transistor amplifier shown as 12 in FIG. 2 is generally conventional. The RF input signal passes through DC blocking capacitor 50 and along path 52 to the gate of the single gate GaAs FET 56. The amplified signal passes through drain electrode 57 and blocking capacitor 63 to the RF input of the RF to IF converter 14.
Referring to FIG. 3 it may be seen that the receiver input is linear up to a RF input level of -25 dbm. Improvements are possible by increasing the voltage feedback in the IF preamplifier, but this reduces the system NF because of the increase in IF preamplifier NF.
FIG. 4 shows how the gain of the amplifier decreases with decreasing supply voltage. Although only the variation in gain with total variation in supply voltage is shown, because this can easily be done, it should be understood that it would be sufficient to change only the gate voltage to obtain a comparable result. Because the gain of the RF preamplifier 12 can be readily accomplished by varying the supply voltage the DC circuit of the RF preamplifier 12, as well as the feedback control circuit are of principle interest to us. Referring again to FIG. 2 and the RF preamplifier circuit 12 it may be seen that the drain is effectively grounded via inductor 62 with respect to the DC supply voltage circuit. In contrast the source is effectively grounded via capacitor 64 with respect to the RF signal but is isolated from ground via capacitor 64 and 60 with respect to the DC supply current. DC bias between the gate and source is provided across resistor 68 path 70 and inductor 58 to junction 54, with the inductor 58 providing RF isolation of the biasing circuit. DC voltage from power source 38 is applied via path 32 to resistor 76 and resistor 72 to the biasing circuit between the gate and the source of the GaAs FET 56. At the junction 77, between resistors 72 and 76, a variable impedance in the form of the transistor 78 is provided so as to permit variation in the supply voltage to preamplifier 12.
As is well known, the collector-emitter impedance of transistor 78 may be varied by varying the bias voltage between the base and emitter electrodes of the transistor. Such a bias voltage is obtained here as a function of the output signal level of IF preamplifier 16. The amplified IF signals are intercepted at junction 20 and applied along path 22 to the input of level control 24 via blocking capacitor 118 to the junction between the diodes 110 and 112. The negative supply voltage from power supply 38 applied along path 34 to one terminal end of resistor 144 essentially forward biases diodes 110 and 112 via resistor 122, which is connected to ground. These diodes provide a voltage divider function as well as rectification of the alternating current RF signal. A portion of the rectified signal is applied to the one input of differential amplifier 104 via path 106.
Capacitor 120 provides a voltage regulating function and with resistor 122 sets a time constant. A fixed bias signal is provided to the other input path 108 of the differential amplifier 104, and this voltage is adjustable via adjustable resistor 134.
The RC network comprising capacitor 98 and resistor 100 at the output of differential amplifier 104 is selected so as to provide the time constant necessary to obtain approximately 100 dB/sec. fade compensation. Multipath fading causes the input level to change at a maximum rate of 100 dB/s in microwave systems. Here though, we are concerned with rain attenuation, so as the 100 dB/s is not of primary concern. Resistor 134 is used to set the output level of the level control 24 so that the bias of transistor 78 is such as to cause the RF preamplifier to operate in a desired gain range. Transistor 82 and its associated elements provide a constant DC gain for the DC output from differential amplifier 104. As a result the base-emitter bias voltage of transistor 78 is adjusted in accordance with the variations of the output of IF preamplifier 16 which, in turn, varies the collector-emitter impedance between junctions 77 and ground. In effect this transistor 78 acts as a shunt regulator to vary the bias voltages applied to the RF preamplifier. Thus the gain of the RF gain preamplifier will change depending upon how much current is shunted through transistor 78, which, in turn, is a function of the IF signal level, and automatic gain control is achieved. Below a certain low input level, the RF Preamplifier gain becomes constant.
In building an amplifier to perform the functions described hereinabove, the techniques was tested using a 6 GHz GaAs FET amplifier which employed an Alpha ALF 1003 device. It was operated from a -8 volt supply and the amplifier current was 20 milliamperes and the circuit provided a gain of 11 dB in the frequency range from 5.9 to 6.4 GHz. The RF preamplifier was designed to provide a -23 dbm output level with normal adjustment of the gain control loop from the IF preamplifier. The levels in the feedback loop were chosen so that an RF level input of -60 dbm the RF preamplifier output level was -23 dbm. With the filter and mixer loss plus the IF preamplifier gain of 24.5 dB, the IF output level was -5 dbm. At a RF input level of -32.7 dbm the output level of the Rf preamplifier is also -23 dbm thus allowing the IF preamplifier output level to remain at -5 dbm. In this design there was no AGC action for RF levels below 32.7 dbm. In testing the unit it was noted that the overload performance of a complete receiver input circuit was above the stated requirement in that the 2A-B products remained 43 dB below the A or B level and thus exceeded the 40 dB level by 3 dB to and input level of -4 dbm. This is also shown in FIG. 6.
In an alternate embodiment of the invention it was shown that the grain of the amplifier decreases if only the gate voltage is varied. In this case an amplifier with a separate drain and gate supply must be built and an example of such an arrangement is shown in FIG. 5. It should be noted that only the biasing method is shown in FIG. 5. For proper operation the drain to source current is again adjusted to 20 milliamps with the drain to source voltage equal to 3 volts, and this was achieved by selecting a gate to source voltage of -1 volt. As the gate to source voltage is adjusted toward 0, the gain of the amplifier decreases in the same manner as if the total supply voltage is varied. Thus AGC action is similar to that obtained by varying the total GaAs FET supply voltage.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that change in form and detail may be made therein without departing from the spirit and scope of the invention. | RF preamplification with AGC is employed because of the wide range of signal levels to which the RF input section of a radio is subjected. A reduction in noise figure is obtained by using a single gate gallium arsenide field effect transistor (GaAs FET) as the RF preamplifier and providing an AGC control signal to vary the gain of the RF preamplifier so that the subsequent circuits are not overloaded when high RF signal levels appear at the input. | 7 |
FIELD OF THE INVENTION
[0001] The invention concerns a method of pressure and gas volume compensation in a fuel tank in relation to changes in pressure and/or volume induced by movement and/or temperature.
[0002] The invention further concerns a fuel tank such as for example for a motor vehicle, capable of providing for pressure and gas volume compensation in relation to changes in pressure and/or volume induced by movement and/or temperature.
BACKGROUND OF THE INVENTION
[0003] Both during a tank refuelling procedure and also while a vehicle in which a tank is used is in operation and stationary, it is necessary to ensure that fuel vapor above the level of fuel in the fuel tank is appropriately discharged so that the fuel tank can be filled with fuel or so that an unacceptably increased pressure is not generated in the tank. In the case of a tank refuelling procedure a volume of gas of up to 60 liters per minute may typically be displaced from the tank by the incoming flow of fuel. The displaced fuel usually involves a mixture of gaseous hydrocarbons and air. Likewise, during normal operation of a motor vehicle, gaseous hydrocarbons are given off, which under certain operating conditions could result in an unacceptable rise in the pressure in the fuel tank. As is known, an increase in temperature increases the tendency on the part of the fuel to change from the liquid phase to the gaseous phase. That phenomenon is further promoted by shaking and rolling movements of the fuel tank. The accumulation of gas in the fuel tank, induced by temperature and/or movement, is usually removed from the fuel tank by way of operational venting conduits, in which case the volatile hydrocarbons are then deposited in a fuel vapor filter which is typically in the form of an activated carbon filter. The fuel vapor filter should be so designed that virtually completely purified air is discharged from the filter to the ambient atmosphere.
[0004] In terms of refuelling a motor vehicle, two different forms of venting are known, more specifically in Europe the very widespread procedure involves suction removal of the displaced volume of gas at the refuelling gun, in which case only a part of the displaced volume of gas is passed to the fuel vapor filter, while in the USA the procedure involves completely removing the volume of gas produced by way of the fuel vapor filter which is fitted in the vehicle.
[0005] At any event residual emissions of hydrocarbons reach the atmosphere through the fuel vapor filter, and that is basically detrimental for reasons relating to the emission of pollutants.
[0006] In this respect reference may be made to U.S. Pat. No. 4,829,968 in which fuel vapor from the free volume in the fuel tank above the level of fuel therein is caught in a collecting container provided with an activated carbon filling and a heating element. The hydrocarbons which are adsorbed by the activated carbon are fed in the gaseous phase under pressure back to the fuel again by way of a sparger discharge unit disposed below the level of the liquid. Within the collecting container which includes a fuel vapor filter air and liquid hydrocarbons are separated in the usual manner by deposit of the hydrocarbons at the activated carbon. The air which is cleared of hydrocarbons in that way is discharged to the atmosphere.
[0007] It will be seen therefore that the problem of pollution of the atmosphere by residual emissions from the fuel vapor filter still applies in this case.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a method of compensating for changes in pressure and/or volume in a fuel tank, such that hydrocarbon emissions to the atmosphere can be very substantially reduced.
[0009] Another object of the present invention is to provide a method of pressure and gas volume equalisation in a fuel tank which affords an effective way of reducing atmospheric pollution due to hydrocarbon emissions from the tank.
[0010] Still another object of the present invention is to provide a fuel tank as for a motor vehicle which allows for compensation of variations in pressure and/or volume in the tank, in such a way as to very substantially eliminate hydrocarbon emissions to the atmosphere due to venting of the tank.
[0011] In accordance with the present invention in the method aspect the foregoing and other objects are attained by a method of pressure and gas volume compensation in a fuel tank in the event of changes in pressure and/or volume induced by movement and/or temperature, wherein any change in pressure outside a predetermined normal pressure range is compensated by condensation of gaseous fuel or gasification of liquid fuel within a system which is hermetically sealed with respect to the atmosphere at least above atmospheric pressure.
[0012] As will be seen in greater detail from the description hereinafter of preferred embodiments of the invention the invention can be summed up to the effect that the fuel tank is held within a predefined normal pressure range as a system which is hermetically closed off with respect to the atmosphere and from which neither vapor nor liquid hydrocarbon emissions can pass outwardly, that is to say to the ambient atmosphere. In this respect the term normal pressure range is used to denote a pressure range which includes all normal operating conditions of a motor vehicle in which the fuel tank is fitted, more specifically when the vehicle is stationary with or without sun acting thereon, when the vehicle is moving, for example when it is moving along without drawing fuel, and operation of the vehicle with fuel being drawn, with frequent changes between acceleration and deceleration. All those operating conditions result in an increased incidence of generation of fuel vapor or increased formation of gas within the fuel tank, which results in a rise in the pressure in the tank. According to the invention a rise in pressure beyond an inadmissible maximum degree is prevented by the volatile hydrocarbons which are generated in the fuel tank being condensed. That is based on the realisation that gasification of liquid fuel involves an increase in volume by about a factor of 1000. In other words, 10 liters of fuel in gas form correspond to approximately 10 ml of fuel in liquid form. Usually a fuel tank has an expansion volume which is still sufficient at the maximum level of filling of the tank. It is rare that a fuel tank will involve more than between about 7 and 10 liters per minute of fuel in gas form which can no longer be held in the expansion volume of the fuel tank. That amount of gas which exceeds the capacity of the expansion volume to accommodate gaseous fuel and which is normally discharged from the fuel tank by way of the fuel vapor filter thereof is to be condensed in order to keep the internal pressure in the tank within admissible limit values. In the event that fuel is taken from the interior of the fuel tank to the engine of the motor vehicle the internal pressure in the tank regulates itself within certain limits by virtue of the resulting drop in pressure entailing an increased tendency on the part of the fuel to go into the gaseous phase.
[0013] In accordance with a preferred feature of the invention an increased pressure in relation to atmospheric pressure is provided as the normal pressure range, for example of the order of magnitude of between 5 and 50 millibars. An increased pressure which in principle obtains in the fuel tank is advantageous in regard to the smallest possible proportion of hydrocarbons or fuel, in gaseous form. Increasing the pressure causes a reduction in the boiling temperature of the fuel so that, with a slightly increased pressure in relation to atmospheric pressure, the fuel is less ready to be transferred from the liquid phase into the gaseous phase.
[0014] As an increased pressure in the fuel tank is not desirable in a refuelling procedure for the increased pressure obtaining in the fuel tank would abruptly escape upon opening of the tank filler cap, a preferred feature of the invention provides that pressure compensation with the atmosphere can be made immediately prior to or upon refuelling. A pressure compensation operation of that kind is then desirably effected by way of the fuel vapor filter which is present in any case, for example on the basis of a starting signal which is derived from the signal related to opening of the tank refuelling flap in the body of the motor vehicle.
[0015] There are various possible ways that can be envisaged for condensing gaseous fuel, for example by way of a temperature drop.
[0016] In accordance with a preferred feature of the invention however condensation of the gaseous fuel is effected within a fuel vapor filter into which the fuel vapor is conveyed or through which the fuel vapor is circulated. The fuel vapor filter generally contains a granular sorbent which by virtue of its adsorptive properties binds the fuel to the internal surface thereof. Binding of the gaseous fuel in a fuel vapor filter in the form of an activated carbon filter has proven to be particularly advantageous.
[0017] It will be appreciated that the effectiveness of an activated carbon filter is greatly reduced by the external surface of the activated carbon being wetted with fuel. It is therefore possible to implement a series of measures intended to ensure that liquid hydrocarbons do not pass into the activated carbon filter. However the effectiveness of the activated carbon filter is not reduced by fuel vapor condensed therein as the fuel vapor is condensed at the internal surface of the activated carbon. Activated carbon has an extremely high storage capacity and can retain condensed fuel over a comparatively wide temperature range. The storage capacity of an activated carbon filter of usual dimensions is readily sufficient to manage the amount of gas which occurs under the above-described operating conditions. A normally designed fuel vapor filter accommodates about 200 grams of hydrocarbons. The filter can then be regenerated in operation of the motor vehicle by way of a suitable purge line.
[0018] In accordance with a preferred feature of the invention the gaseous fuel is transported by means of a gas delivery pump.
[0019] Refuelling of the fuel tank can also involve the formation of not inconsiderable amounts of gas which are displaced out of the interior of the tank by the liquid fuel. Depending on the refuelling speed, as mentioned above, up to 60 liters per minute of volume can be displaced. The amount of gas produced can either be passed entirely by way of the fuel vapor filter or can be removed by a suction effect at the refuelling gun. In the latter case it is desirable if delivery or circulation of the gaseous fuel into or through the fuel vapor filter is effected at least from time to time also in a refuelling procedure, even if the closed nature of the system in relation to the ambient atmosphere naturally cannot be maintained in the refuelling procedure.
[0020] It is possible to envisage situations in which the internal pressure of the tank falls below the defined normal pressure range. In that case it would be possible on the one hand to produce pressure equalisation with the atmosphere by opening the system, or alternatively it is possible for the fuel which has condensed in the fuel vapor filter to be converted into the gaseous phase again in order to produce a rise in the pressure in the fuel tank.
[0021] Preferably, when the internal pressure of the tank is below the normal pressure range, unloading of the fuel vapor filter can be effected by virtue of a reversal in the direction of delivery of the gas delivery pump feeding into the interior of the tank.
[0022] Also in accordance with the invention in the tank aspect the foregoing and other objects of the invention are attained by a fuel tank for a motor vehicle, comprising means for pressure and gas volume compensation in relation to changes in pressure and/or volume induced by movement and/or temperature, comprising at least one fuel vapor filter, and at least one operational venting conduit connected to the fuel vapor filter. The outlet of the fuel vapor filter is closed with respect to the atmosphere at least under normal operating conditions of the motor vehicle and in relation to changes in pressure and/or volume within the tank induced by movement and/or temperature, by way of a first valve means.
[0023] In a preferred feature of the invention the fuel tank further has means for conveying the fuel vapor into the fuel vapor filter.
[0024] For example, for conveying the fuel vapor the fuel tank may have at least one gas delivery pump disposed in the operational venting conduit of the fuel tank.
[0025] In a further preferred feature the fuel vapor filter is in the form of an activated carbon filter.
[0026] The fuel vapor filter can be connected on the one hand to the operational venting conduit and on the other hand by way of a return conduit to the interior of the container, or can communicate in that way with the volume of the container.
[0027] Alternatively the fuel vapor filter can be connected on the one hand to the operational venting conduit and on the other hand to at least one closed gas storage means.
[0028] Desirably the fuel tank may include a second valve means operable to close the operational venting conduit.
[0029] In a preferred feature the first valve arrangement may include at least one excess pressure valve. That is appropriate in particular for the reason of permitting pressure equalisation of the fuel tank with the atmosphere in the event of an inadmissibly high internal pressure in the tank in a situation involving unusual operating conditions or in the event of failure of the control means of the fuel tank.
[0030] Further objects, features and advantages of the invention will be apparent from the description hereinafter of preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0031] [0031]FIG. 1 is a diagrammatic view of a fuel tank in section in a first embodiment of the invention, and
[0032] [0032]FIG. 2 is a diagrammatic view of a fuel tank in section in a second embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] Referring firstly to FIG. 1, reference numeral 1 therein denotes a fuel tank as for a motor vehicle which in the usual manner includes a filler pipe 2 with a cap closure 3 and a fuel delivery 4 with which fuel can be delivered from the fuel tank 1 to the engine of a motor vehicle (not shown) by way of the fuel feed line generally identified by reference 5 .
[0034] It will be noted at this point that the invention is not limited to use in relation to motor vehicle tanks but can be employed in relation to fuel tanks generally.
[0035] The fuel delivery unit 4 includes a swirl pot 6 , also referred to as a surge pot, and a fuel pump 7 which is arranged therein and which supplies fuel to the fuel feed line 5 .
[0036] The fuel feed system and other functional components of the fuel tank 1 are not shown here or are shown only in highly diagrammatic form for the sake of simplicity of the drawing and because the general structure and arrangement thereof are well known in the art and therefore do not need to be described in detail at this juncture.
[0037] Provided within the fuel tank 1 is a fuel vapor filter in the form of an activated carbon filter 9 which communicates with the internal volume of the fuel tank by way of an operational venting conduit 10 . Above the level of fuel in the fuel tank 1 , which is shown by way of indication in the lower part thereof, is a fuel gas-air mixture which, either upon refuelling of the fuel tank 1 or in the event of an unacceptable rise in the pressure within the fuel tank 1 , has to be discharged from the fuel tank 1 . Hereinafter the free volume above the level of fuel, constituting a head space in the fuel tank 1 , is referred to for the sake of simplicity as the expansion volume.
[0038] In the case of known fuel tanks the endeavour hitherto was to provide for pressure equalisation between the interior of the fuel tank and the ambient atmosphere. The interior of the fuel tank was in continuous communication with the atmosphere by way of an activated carbon filter. It is here that the invention seeks to afford a remedy in regard to such communication for the purposes of minimising the level of emissions resulting therefrom.
[0039] In the embodiment described herein the fuel tank 1 is hermetically closed off in operation of the motor vehicle or when it is stopped, that is to say for example when it is not being refuelled. Disposed within the fuel tank 1 in the expansion volume thereof is the above-mentioned operational vent conduit 10 which is passed out of the fuel tank 1 from the expansion volume thereof by way of the activated carbon filter which is indicated at 9 and which comprises a filter container with sorbent therein.
[0040] A first switchable valve 11 which is closed when in an unpowered condition closes the venting conduit 10 downstream of the activated carbon filter and thus closes off the entire fuel tank 1 in relation to the ambient atmosphere. A second switchable valve 12 which is also closed in an unpowered condition closes the operational venting conduit 10 upstream of the activated carbon filter 9 . It will be seen that the operational venting conduit 10 opens in this region into the expansion volume of the fuel tank 1 .
[0041] It will be noted at this point that the activated carbon filter 9 as well as the operatively associated valves, lines and other devices do not necessarily have to be arranged within the fuel tank 1 , but such a design arrangement is generally preferred.
[0042] Reference 13 denotes a gas delivery pump arranged in the operational venting conduit 10 between the first valve 12 and the activated carbon filter 9 .
[0043] In accordance with the invention when the motor vehicle in which the fuel tank 1 is fitted is stopped or when fuel is being drawn from the fuel tank by the engine of the motor vehicle the first and second valves 11 and 12 are closed. When the cap 3 on the filler pipe 2 is also closed the fuel tank 1 is hermetically closed off with respect to the ambient atmosphere or the environment.
[0044] At least the second valve 12 is actuatable only above a predefined normal pressure range, for example above 50 millibars internal pressure in the tank, being actuated more specifically by virtue of a control signal which is generated in dependence on pressure by a control device 17 within the tank. There is no active control of the tank pressure below a tank internal pressure of 50 millibars, to about ambient pressure. The further generation of hydrocarbon-gas mixture is throttled by virtue of a slightly increased pressure in the fuel tank 1 .
[0045] If the proportion of gas in the fuel tank 1 increases by virtue of a rise in temperature or by virtue of the dynamics of movement of the motor vehicle in which the fuel tank 1 is fitted, that results in the pressure within the fuel tank rising beyond the normal pressure range. In that case the second valve 12 opens and the fuel delivery pump circulates the fuel gas in the expansion volume of the fuel tank 1 through the operational venting conduit 10 and through the activated carbon filter 9 and the return conduit 15 connected downstream thereof. That results in condensation of the fuel gas in the activated carbon filter 9 and an immediate interruption in the rise in pressure within the fuel tank 1 . The residual gases issuing from the activated carbon filter 9 are passed back into the fuel tank 1 by way of the return conduit 15 . If under very extreme loadings the internal pressure in the fuel tank 1 should not be reduced below an acceptable limit value, a situation which is detected by a pressure sensor 16 , a signal is generated by the control device 17 for opening the valve 11 . Opening of the valve 11 results in immediate pressure equalisation with the ambient atmosphere, inter alia also because a diagnosis valve 14 connected downstream of the first valve 11 is open in the unpowered condition. The purpose of the diagnosis valve 14 is to temporarily hermetically shut off the entire fuel tank 1 for the purposes of checking sealing integrity. If the pressure falls below a pressure limit established in the control device 17 of for example 65 millibars by virtue of opening of the venting conduit 10 to the atmosphere by way of the first valve 11 then the first valve 11 is closed again. Below 50 mbar the gas delivery pump 13 is also switched off in order to keep the internal pressure in the fuel tank constantly above atmospheric pressure.
[0046] Electrical control is not possible in the event of the motor vehicle having no power. In that case the pressure in the fuel tank 1 is kept below the previously established upper limit of the normal pressure range, outgassing being minimised by that increased pressure. References 11 a and 12 a in FIG. 1 denote excess pressure valves which, even when there is no power in the system, above the established upper limit of the normal pressure range, allow pressure equalisation with the ambient atmosphere, more specifically by way of the diagnosis valve 14 which is open in the unpowered condition.
[0047] Reference numeral 11 b denotes a check valve which, when the first valve 11 is in the closed condition, in the event of an inadmissible reduced pressure in the fuel tank 1 , permits a feed flow of ambient air.
[0048] When the fuel tank 1 is being refuelled a signal is passed to the control device 17 immediately prior to opening of the fuel tank 1 . When the diagnosis valve 14 is open, the signal sent to the control device 17 causes opening of the valves 11 and 12 so that any increased pressure present in the fuel tank 1 can be immediately equalised to the atmosphere. The signal line for carrying the opening signal from the cap 3 on the filler pipe 2 is only shown by way of indication as a broken line in FIG. 1.
[0049] The gas delivery pump 13 can be temporarily switched on to reduce the internal pressure in the fuel tank at the beginning of a refuelling procedure.
[0050] In a refuelling procedure the hydrocarbon-laden gases can be conducted past the activated carbon filter 9 directly to the filler pipe 2 in order for them then to be removed by suction at the filler gun, as in the case of the European system referred to hereinbefore. In that case unnecessary loading of the activated carbon filter 9 is avoided in a refuelling procedure.
[0051] In order to avoid excessive ingress of ambient air into the fuel tank 1 in a tank refuelling operation a recirculation conduit indicated at 18 is connected between the filler pipe 2 and the interior of the tank.
[0052] When a small amount of gas is produced during a refuelling procedure the diagnosis valve 14 or the valve 11 can be temporarily closed and the gas delivery pump 13 switched on. The residual gases from the activated carbon filter 9 are then urged back into the tank by way of the return line 15 .
[0053] Also disposed in the interior of the tank 1 is a level sender as indicated at 19 . If the level sender 19 signals that the tank is in the condition of being full the control device 17 causes closure of the valves 11 and/or 12 whereby the end of the refuelling procedure is initiated, that is to say a rapid rise in pressure in the interior of the tank 1 causes the automatic shut-off valve of the refuelling gun to be shut off.
[0054] Reference numeral 21 in FIG. 1 denotes a purge valve, by way of which a communication can be made from the operational venting conduit 10 to the engine of the motor vehicle. When the purge valve 21 is opened hydrocarbon-charged gas is passed by way of the activated carbon filter 9 to the combustion air of the engine for the purposes of regeneration of the activated carbon filter 9 .
[0055] Reference will now be made to FIG. 2 showing an alternative configuration of the fuel tank 1 according to the invention. It will be seen that the structure of the fuel tank shown in FIG. 2 is generally the same as that of the fuel tank shown in FIG. 1, so that for the sake of simplicity and brevity only the differences between the two structures will be described in greater detail here. For that reason identical components which appear in both FIGS. 1 and 2 are denoted by the same references.
[0056] Looking therefore now more specifically at FIG. 2, in this embodiment the activated carbon filter 9 is not provided with a return line communicating with the interior of the tank 1 , such line being indicated at 15 in FIG. 1, but rather a gas storage means as indicated at 20 in FIG. 2 is connected on the downstream side of the activated carbon filter 9 .
[0057] In operation of the motor vehicle or when it is stopped above the normal pressure range the gas delivery pump 13 , with the second valve 12 in the open condition and the first valve 11 in the closed condition, passes hydrocarbon-charged gas through the activated carbon filter 9 into the downstream-connected gas storage means 20 . The gas storage means 20 is closed off in the delivery direction. As soon as the pressure in the gas storage means 20 has risen to such a degree that the gas delivery pump 13 can no longer increase it any further, the purified air is passed back into the interior of the fuel tank 1 again through the activated carbon of the activated carbon filter 9 , more specifically independently by virtue of the pressure drop which occurs after the gas delivery pump 13 is switched off. That periodic unloading of the gas storage means 20 results generally in enrichment of the activated carbon filter 9 as the purified air which is discharged by way of the gas storage means 20 , as it passes back through the activated carbon filter 9 , takes up less hydrocarbons than it previously discharged.
[0058] At any event in both of the above-described embodiments of the invention unloading of the activated carbon filter 9 is possible by a reversal in the delivery direction of the gas delivery pump, more specifically because of the degree of saturation which then rises in the activated carbon filter in opposite relationship to the delivery direction. That results then in a rise in pressure in the interior of the tank 1 . In the embodiment described with reference to FIG. 1, upon the reversal in the direction of delivery of the gas delivery pump 13 , the check valve identified by reference 8 becomes operative in the return line 15 in this embodiment. In both cases the reversal in the delivery direction of the gas delivery pump 13 results in the production of a reduced pressure in the activated carbon filter 9 and that reduced pressure in turn results in increased discharge of the hydrocarbons bound therein. In addition unloading of the activated carbon filter 9 can be implemented by heating it, for example by means of a heating element suitably arranged in the activated carbon filter 9 .
[0059] It will be noted that a rise in pressure in the fuel tank 1 can also be implemented in the usual manner by a feed of fresh air, in particular when the pressure falls below a critical reduced pressure. As already mentioned above however a feed of fresh air into the fuel tank 1 should be avoided as far as possible.
[0060] It will be appreciated that the above-described embodiments of the invention have been set forth solely by way of example and illustration of the principles thereof and that various modifications and alterations may be made therein without thereby departing from the spirit and scope of the invention. | In a method of pressure and/or gas volume compensation within a fuel tank in relation to movement-induced and/or temperature-induced changes in pressure and/or volume, as when fuel is drawn from the tank and upon refuelling of the tank, any changes in pressure outside a predetermined normal pressure range are compensated by condensation of the gaseous fuel or gasification of the liquid fuel within a system which is hermetically closed off at least above atmospheric pressure. The invention also provides a tank operating on that basis. | 1 |
BACKGROUND
[0001] 1. Field
[0002] The present disclosure relates generally to translation lookaside buffers, and more specifically, to methods and systems for optimizing translation lookaside buffer entries.
[0003] 2. Background
[0004] Many existing computer systems today utilize virtual memory. Virtual memory is a technique that abstracts memory into a large, uniform array of virtual storage, which exceeds memory readily available to the processor. This separation allows a large virtual memory to be provided for programmers when only a smaller physical memory, commonly a semiconductor memory (such as but not limited to RAM or DRAM) hereinafter referred to simply as “memory”, is available, thereby freeing programmers from concern over memory storage limitations. As a result, numerous applications can be launched by loading portions of them from higher latency hard drive storage to lower latency memory even though the lower latency memory is not large enough to hold them all. This may be achieved by identifying portions of memory that have not been used recently and copying them back onto the hard drive. This frees up space in memory to load new portions of memory for more immediate use.
[0005] In many processing systems today, a central processing unit (CPU) uses virtual memory to execute programs. In such processing systems a virtual address is mapped to a corresponding physical address. Typically, this mapping is performed by a translation lookaside buffer (“TLB”), which is nothing more than a memory that maps the most often used virtual memory page addresses to their corresponding physical memory page addresses.
[0006] Commonly, each TLB entry maps one page in memory to a virtual memory page address. This limits the number of addresses that can be represented by each TLB entry. Since maintaining a TLB requires system resources, it would be desirable to provide more efficient methods and systems for optimizing TLB entries by consolidating multiple contiguous page entries into a single entry.
SUMMARY
[0007] A processing system is disclosed. The processing system includes a translation lookaside buffer (TLB) configured to map a contiguous block of virtual memory to physical memory, and provide a size attribute indicating the size of the contiguous block of virtual memory, and a processor configured to vary the size of the contiguous block of virtual memory and the corresponding physical memory, and vary the size attribute accordingly.
[0008] Another aspect of the processing system is disclosed. The processing system includes a translation lookaside buffer (TLB) configured to store a plurality of entries, each of the entries mapping a contiguous block of virtual memory to physical memory, and each of the entries having a size attribute indicating the size of its respective block of virtual memory, and a processor configured to vary the size of the contiguous block of virtual memory and the corresponding physical memory for one of the entries, and wherein the processor is further configured to vary the size attribute for said one of the entries.
[0009] A method of storing a plurality of entries in a translation lookaside buffer (TLB) is disclosed. The method includes mapping a contiguous virtual memory block to physical memory, providing a size attribute indicating the size of the contiguous block of virtual memory, varying the size of the contiguous block of virtual memory and the corresponding physical memory, and varying the size attribute to reflect the change in the contiguous block of virtual memory and the corresponding physical memory.
[0010] Another aspect of a method of storing a plurality of entries in a translation lookaside buffer (TLB) is disclosed. The method includes identifying a new block of virtual memory, locating an entry in the TLB having an existing block of virtual memory that is contiguous with the new block of virtual memory, the TLB entry containing a mapping between the existing block of virtual memory and physical memory, and consolidating the new and existing blocks of virtual memory, and their corresponding physical memory, in the TLB entry, the consolidation of the new and existing blocks of virtual memory further comprising adjusting a size attribute to reflect a change in the size from the existing block size of virtual memory to the consolidated block size of virtual memory.
[0011] It is understood that other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a simplified block diagram illustrating a system for optimizing translation lookaside tables according to the present disclosure;
[0013] FIG. 2 is a simplified schematic diagram showing a TLB entry according to the present disclosure; and
[0014] FIG. 3 is a simplified schematic diagram showing a TLB entry and a proposed entry for use in an illustration according to the present disclosure.
DETAILED DESCRIPTION
[0015] The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the present invention.
[0016] FIG. 1 is a conceptual block diagram illustrating an example of a data processing system 100 . The data processing system 100 may be a stand-alone system, or alternatively embedded in a device such as a wired or wireless phone, Personal Digital Assistant (PDA), Personal Computer (PC), laptop, digital camera, game console, pager, modem, video conferencing equipment, or any other suitable device. The data processing system 100 may include a processor 102 , such as a microprocessor or other processing entity. The processor 102 may be used as a platform for to run any number of applications including, by way of example, an operating system, a Web browser, an e-mail system, a word processor, as well as other software programs to support video, telephony, and the like.
[0017] The processing system 100 may also include memory 104 , which holds the program instructions and data needed by the processor 102 to perform its functions. The memory 104 may be implemented with Random Access Memory (“RAM”) or other suitable memory, and may serve as the processor's main memory, a L2 cache, or a combination thereof. Program instructions for the various programs launched by the processor 102 may be loaded from a non-volatile storage device 106 , such as a hard drive, to memory 104 .
[0018] A TLB 108 may be used to map memory page addresses from 106 , which may comprise for exemplary purposes a non volatile storage device, to corresponding page addresses in memory 104 . The TLB may be a relatively small, high-speed cache that is integrated into the processor 102 , but is shown separate from the processor 102 for illustration purposes. When the processor 102 needs to access memory 104 , it searches the TLB 108 for a virtual memory page address. If the processor 102 finds the virtual memory page address in the TLB 108 , a “TLB hit” has occurred. On a TLB hit, the processor 102 retrieves the corresponding physical memory page address from the TLB 108 and provides it to the memory 104 over an address bus 110 . The processor 102 can then access the contents of that address in memory 104 to perform either a read or write operation over a data bus 112 .
[0019] In the event that the processor cannot find the virtual memory page address in the TLB 108 , a “TLB miss” has occurred. Various techniques for handling a TLB miss are well known in the art, and therefore, will not be discussed any further except to say that the processor 102 can invoke certain processing functions to determine the physical memory page address required for it to perform its current operation. Once it determines the physical memory page address, the processor can access memory 104 , which may or may not require program instructions to be transferred between memory 104 and the non-volatile storage device 106 . A new TLB entry may be created in the TLB 108 to handle future access to the same physical memory page address.
[0020] The processor 102 may be configured to dynamically manage the number of pages that can be stored in a single TLB entry. As shown in FIG. 2 , each TLB entry 200 in the TLB 108 may include a virtual memory page address 202 and a physical memory page address 204 . As explained above, the virtual memory page address 202 is mapped to the physical memory page address 204 , which corresponds to a page in memory (not shown). A size attribute 206 may be appended to the virtual memory page address 202 . The size attribute 206 may be used to indicate the number of pages represented by each TLB entry.
[0021] In at least one embodiment of the data processing system, the processor may be configured to adjust the size attribute for a given TLB entry on a dynamic basis. This may be achieved in a variety of ways. Returning back to FIG. 1 , when a TLB miss occurs, the processor 102 invokes certain processing functions to determine the physical memory page address required for it to perform its current operation. However, before the processor 102 creates a new TLB entry, it first determines whether the proposed new entry is contiguous with an existing entry in the TLB 108 . Two entries in the TLB 108 are said to be contiguous if both the virtual memory page addresses are contiguous and the physical memory page addresses are contiguous. If the processor 102 determines that contiguity exists with an existing TLB entry, then the two virtual memory pages and the two physical memory pages may be consolidated into a single entry in the TLB 108 . The size attribute 206 (see FIG. 2 ) may be increased to indicate that the virtual memory page address and the corresponding physical memory page address represents two pages in memory 104 . Alternatively, if the processor 102 determines that contiguity does not exist with an existing TLB entry, a new TLB entry may be created.
[0022] The following is an illustrative example showing how the processor 102 optimizes entries in the TLB 108 . FIG. 3 shows an existing entry 300 in the TLB and a proposed new entry 302 . The existing entry 300 may include a size attribute, a virtual memory page address having a most-significant-bit portion (X 1 ) and a least-significant-bit (Y 1 ), and a corresponding physical memory page address having a most-significant-bit portion (A 1 ) and a least-significant-bit (B 1 ). The size attribute is set to indicate that the TLB entry represents one page of memory. Portion X 1 is made up of bits 13 - 31 and portion Y 1 is made up of bit 12 . Similarly, the proposed new entry 302 may include a virtual memory page address having a most-significant-bit portion (X 2 ) and a least-significant-bit (Y 2 ), and a corresponding physical memory page address having a most-significant-bit portion (A 2 ) and a least-significant-bit (B 2 ). It should be noted that, for both the existing entry 300 and the proposed entry 302 , bits 0 - 11 correspond to the offset portion of the address and thus are not part of the entry.
[0023] The processor determines whether the existing entry 300 and the proposed entry 302 can be optimized as follows. First, the virtual memory page addresses of the existing entry 300 and the proposed entry 302 are compared. If X 1 =X 2 and Y 1 =Y 2 , then it is considered a TLB hit. As explained earlier, the processor may then retrieve the corresponding physical memory page address from the TLB and place it on the address bus to access memory. If, on the other hand, X 1 ≠X 2 or Y 1 ≠Y 2 , then it is considered a TLB miss. Assuming that the processor cannot obtain a TLB hit with another TLB entry, it invokes certain processing functions to determine the corresponding physical memory page address. However, before a new TLB entry is created, the proposed entry 302 is checked for contiguity with the existing entries in the TLB.
[0024] In the example shown in FIG. 3 , the proposed entry 302 is checked for contiguity against the existing entry 300 in response to a TLB miss. This may be achieved with a four step process. First, the virtual memory page addresses are checked for contiguity by comparing X 1 to X 2 , and Y 1 to Y 2 . If X 1 =X 2 and Y 1 ≠Y 2 , then the virtual memory page addresses are off by one least-significant-bit, and said to be contiguous in virtual memory address space. Second, the physical memory page addresses are checked for contiguity by comparing Al to A 2 , and Bi to B 2 . If A 1 =A 2 and B 1 ≠B 2 , then the physical memory page addresses are also off by one least-significant-bit, and said to be contiguous in physical memory address space. Third, the virtual and physical memory page address of the existing entry and the proposed entry are then checked to ensure that the proposed entry's virtual and physical memory page addresses are both either higher than or lower than the existing entry's virtual and physical memory page addresses, respectively. Finally, when the existing and proposed entries are to be consolidated into one larger entry, the virtual and physical page address ranges covered by the larger entry are checked to ensure that both address ranges are aligned on the large size boundary. If all these conditions are met, then the existing and proposed entries can be consolidated into a single entry. In the case where the virtual and physical memory page addresses for the proposed entry 302 are higher than that for the existing entry 300 , then the two entries can be consolidated by merely increasing the size attribute to indicate that the consolidated TLB entry represent two pages in memory beginning at the virtual and physical memory page addresses of the original entry 300 . Alternatively, where the virtual and physical memory page addresses for the proposed entry 302 are lower than that for the existing entry 300 , then the two entries can be consolidated by writing the proposed virtual and physical memory page addresses over the existing entry and changing the size attribute to indicate that the consolidated TLB entry represent two pages in memory beginning at the virtual and physical memory page addresses of the new entry 302 .
[0025] An example will now be provided. Assume that the virtual memory page of the existing entry 300 is 4 KB starting at address “0x0000 — 0000”, and the corresponding physical memory page is 4 KB page starting at address “0x8000 — 0000”. If the virtual memory page for the proposed entry 302 is 4 KB page starting at address “0x0000 — 1000”, and the corresponding physical memory page is 4 KB page starting at address “0x8000 — 1000”, then both entries can be consolidated into an 8 KB region starting at the same addresses as the existing entry. However, if the existing entry's virtual region started at address “0x0000 — 1000” and its corresponding physical region at address “0x8000 — 1000”, and the proposed entry's virtual region started at address “0x0000 — 2000” and its corresponding physical region at address “ 0x8000 — 2000”, then the existing and proposed entries could not be combined, because the resultant 8 KB page would not start at a boundary that is aligned on an 8 KB region.
[0026] Consequently, assuming the contiguity check is satisfactory, the size attribute in the existing entry 300 is dynamically changed to 8 KB. The 8 KB size is based on the fact that the existing page is 4 KB and the new page is 4 KB. Hence, consolidating or combining the new page and the existing page results in an 8 KB page. As the foregoing example illustrates, if an existing page that is contiguous to a new page can be located in the TLB, the entry for the existing page can simply be modified and no separate entry need to be added to the TLB for the new page.
[0027] In addition, the modified (8 KB) entry may need to have Y 1 and B 1 both set to “0”, if they weren't already both “0”. This is performed so that the modified entry correctly reflects the starting address of the new 8 KB page (that is, the lower-numbered of the two contiguous 4 KB pages). However, it should be noted that not all implementations would require this change. Essentially, when a 4 KB entry is converted to an 8 KB entry, bit 12 of the existing entry changes from being the least-significant bit of the virtual page address to effectively being the most-significant bit of the offset (not shown). The offset is used to form the complete physical page address with which to access memory. The offset is not important in the translation or mapping process between virtual page address and physical page address. The size attribute of the entry being 8 KB (rather than 4 KB) indicates that bit 12 is now part of the offset. As such, bit 12 of the virtual page address no longer needs to be considered part of the TLB entry and, hence, does not need to participate in the comparison against subsequent addresses to determine a match. Some implementations can properly and automatically ignore this bit position, in both the virtual and the physical page address portions of the TLB entry, based upon the size attribute. Other implementations may require one or the other, or both, of these bit positions to reflect the lower-numbered page address (in other words, for them to be 0's).
[0028] Based on the disclosure and teachings provided herein, it will be appreciated that the foregoing can be extended to accommodate consolidation of larger page sizes. Using the modified entry 300 for further illustration, the entry 300 now references an 8 KB page (since two (2) contiguous 4 KB pages have been consolidated). The processor 102 (see FIG. 1 ) can be further configured to now search for an entry in the TLB 108 that references another 8K page that is contiguous to the 8K page referenced by the modified entry 300 . If it is determined that there is another 8K page contiguous to the 8K page referenced by the modified entry 300 , then the size attribute of one of the two existing entries can be modified to now reflect that the page size for that entry is 16K and the remaining entry can be eliminated. As a result, a 16K page is now referenced by a single entry, as opposed to two (2) contiguous 8K pages referenced by two (2) different entries. Expanding the foregoing further, another existing 16K page that is contiguous to the newly consolidated 16K page can also be consolidated to form a 32K page that is referenced by a single entry. The foregoing can be extended to consolidate pages into increasingly larger page sizes.
[0029] Optionally, the processor 102 (see FIG. 1 ) can also be configured to consolidate entries referencing pages with smaller page sizes to create an updated entry referencing a page with a desired page size. The updated entry can then be consolidated with another entry that references a page having the same desired page size. For example, using the modified entry 300 again for illustration, the entry 300 now references an 8K page. The processor 102 (see FIG. 1 ) can first consolidate two (2) contiguous 4 KB pages to create an 8 KB page referenced by a single entry. The newly created 8 KB page can now be further consolidated with the 8 KB page referenced by the entry 300 to form a 16KB page referenced by a single entry. Similarly, the processor 102 can then consolidate four (4) contiguous 4 KB pages to form another 16KB page referenced by another entry. Subsequently, the newly formed 16KB page can be consolidated with the previously formed 16KB page to form a 32KB page. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will understand how to expand the foregoing to optimize entries in the TLB 108 to cover other larger page sizes according to the present disclosure.
[0030] The various illustrative logical blocks, modules, circuits, elements, and/or components described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic component, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing components, e.g., a combination of a DSP and a microprocessor, a number of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
[0031] The methods or algorithms described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executable by a processor, or in a combination of both, in the form of control logic, programming instructions, or other directions. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. A storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor.
[0032] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit of scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for”. | A system for optimizing translation lookaside buffer entries is provided. The system includes a translation lookaside buffer configured to store a number of entries, each entry having a size attribute, each entry referencing a corresponding page, and control logic configured to modify the size attribute of an existing entry in the translation lookaside buffer if a new page is contiguous with an existing page referenced by the existing entry. The existing entry after having had its size attribute modified references a consolidated page comprising the existing page and the new page. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention refers to a process for separation of fluids in emulsion and/or in solution, and/or for low pressure distillation of fractions of same, and to the device for implementing the process. The separation of the fluids will be done by locally reducing the relative pressure on a particular part of the free surface of the liquids, the process making possible the degasification and separation of the liquids contained in a closed processing tank, without affecting the service pressure prevailing inside the processing tank.
2. Discussion of the Background
The separation as stated above, in accordance with the background art, is done by applying a partial vacuum to the processing equipment in its entirety and not just to a part of its interior.
Also according to the background art, in the case of large processing tanks, the costs of construction and installation of the same so as to withstand negative pressures are elevated, and what is more there is always the risk of vacuum-induced collapse and explosion due to fuel getting in.
Moreover according to the background art, the hydrocarbon processing industry is quite familiar with two or three phase separators, which operate on the basis of the Stokes law, these being used for the separation of liquids in emulsion and gases in solution, such separation being relatively slow.
SUMMARY OF THE INVENTION
One object of the present invention is to do away with the above drawbacks, by providing a process based on the Bernoulli laws, according to which a fluid in moving over a surface brings about a pressure reduction at the surface, one conspicuous example of its application being the creation of lift on the wings of aircraft, in that the pressure reduction at the upper surface or extrados of the wing is greater than the pressure reduction on the lower surface or intrados of the wing, owing to the more convex profile (the extrados) of the former, which forces the air to move more quickly on this one than on the intrados, thereby producing, thanks to the pressure difference at the two surfaces, a force directed upward, providing the lift characteristic of the wing.
Consequently, the present invention applies the principle of pressure reduction with increase in velocity of a gas moving over a surface and tangentially to the same, so that, in the processing device where this localized pressure reduction is generated, there is encouraged a separation of fluids in emulsion and/or in solution, and/or a low pressure distillation of the components of the fluid, the evaporated components afterwards being processed and recovered.
A current of gas projected onto and tangentially to a free surface of a liquid will bring about a pressure reduction at the area of contact between the gas and the liquid, as described above, creating the conditions for the components with less vapor pressure to gradually separate from the liquid, as well as a faster migration to the surface of the dissolved gases and of the liquid in emulsion with less specific gravity.
According to the invention, the localized pressure reduction at the particular part of free surface of the liquid is achieved by projecting a current of gas against the particular part of the free surface and tangentially to same, and the current of processing gas before making contact with the free surface makes an angle which can vary between zero and thirty degrees. Preferably, the angle is five degrees.
The processing gas which is projected onto the surface is a gas compatible with the liquid contained in the processing tank or an inert gas, so as to eliminate any risks inherent to the nature of the liquid, such as fire, pollution, explosion, etc.
The gas current can be applied in a particular part of the free surface of a liquid contained in a closed processing tank or it can be applied on a specific surface over which the liquid will flow so as to increase the area/volume ratio and thus the separation yield and the volume of liquid being processed. In this case, the surface can be planar or assume any other adequate shape for the intended purpose, preferably the shape of the extrados of an aircraft wing.
Therefore, one way of improving the process of the present invention is to use a platform on whose surface the liquid to be processed flows, so as to increase the area/volume ratio of liquid on the free surface of the platform, and to project a current of gas onto the surface tangentially, the current of processing gas making a certain angle before it comes into contact with the free surface, which can vary between zero and thirty degrees, the angle being preferably five degrees. In accordance with what has just been noted, such a platform preferably will have the shape of the extrados of an aircraft wing.
The generating of a localized pressure reduction inside a closed processing tank on the particular part of free surface of the liquid by projecting a the current of processing gas against and tangentially to the same, the current of processing gas making a particular angle before coming into contact with the surface, in accordance with the present invention, is novel with regard to the background art.
The present invention can be applied especially to petroleum products, without restricting its application to other fluids and, in particular, to the separation of water in emulsion and gases in solution in crude petroleum or in its subproducts, and/or to distillation of fractions of crude petroleum or its subproducts, by a pressure reduction on a particular part of the surface of the crude petroleum, or its subproduct, without generating a partial vacuum or excess pressure in the internal environment of the processing tank or receptacle, being therefore more efficient in terms of process speed, energy consumption, cheapness and safety, than background processes for the same purpose.
One case illustrating the present invention is a closed processing tank, inside which the pressure is reduced in only one particular part of the free surface of the liquid, by the projecting of a current of processing gas against the part of free surface of the liquid, thereby generating a pressure reduction in the zone of contact between the part of free surface of the liquid and the current of processing gas, such that the range of influence of the reduced pressure does not affect the general pressure inside the tank, which does not undergo any reduction, and therefore no outside gases are admitted into the tank, with the accompanying risk of formation of flammable mixtures, an explosion.
One application of the process of the present invention involves the separation of crude petroleum, coming from the production wells, from the water which it contains in emulsion and from part of the gas in solution in same. The crude petroleum, stored within a processing tank, will be made to flow over a platform, arranged for this purpose inside the tank at a certain distance above the free surface of the crude petroleum, which may or may not be heated, against which there is made to impinge a current of gas onto the free surface of the crude petroleum in movement on the platform and tangentially to the surface, the current of gas making an angle before impinging on the surface, which may vary between zero and thirty degrees, the angle preferably being five degrees, bringing about a pressure reduction on the free surface, and the crude petroleum being continually recirculated, until one has achieved a substantial migration of the water to the bottom of the receptacle, from which it is drained, and the liberation of the gases in solution in the crude petroleum, and the desired final product is obtained, namely, crude petroleum with lesser percentage of water and stabilized at the required temperature by degasification. It is within the scope of the invention to arrange several other platforms placed in series within the processing tank.
Another application of the process of the present invention includes the separation of the water coming from the above-mentioned processing from the residual hydrocarbons so that it can be injected, upon reaching a concentration of hydrocarbons on the order of 15 parts per million or less, into the subsoil without polluting the existing paretic zones with such hydrocarbons, the water being subjected to a processing equal to that of the preceding paragraph. Thanks to the pressure reduction on the platform, the droplets of crude petroleum and the gases lighter than water tend to evaporate and will either be entrained by the current of gas or will emerge onto the surface for subsequent decanting.
It is within the scope of the invention that the projecting of a current of processing gas is done either in opposite current or concurrent manner.
It is also within the scope of the invention that the process of the present invention can be done inside a hydrocyclone. As is known, hydrocyclones make possible, for a particular volume of equipment, a greater area of contact with a current of processing gas. The processing gas is projected against the crude petroleum, containing water and gas, which upon being centrifuged against the walls of the hydrocyclone during the centrifugation process inside the hydrocyclone, creates an interior free surface of truncated conical shape, with the hydrocarbons being closer to the axis and the water to the walls. The current of processing gas is then projected onto and tangentially to this surface with an annular shape, the current of processing gas making an angle before coming into contact with the surface, which can vary between zero and thirty degrees. Preferably, the angle is five degrees. In this way, one obtains a cylindrical contact surface between the gas and the liquid, which allows one to apply the process of localized pressure reduction on a greater surface for a particular equipment volume. The hydrocyclone can be installed independently or it can be an integral part of the processing equipment.
It is also within the scope of the invention to carry out the process within an independent apparatus or one inserted within processing equipment such as, without being restricted hereto, storage tanks, dehydration and degasification tanks, and phase separators.
It is also within the scope of the invention to use Venturis in order to create the localized partial vacuum on a surface. As is known, Venturis are static machines used for the movement of fluids, which exploit the partial vacuum created by the application of a driving fluid.
The aspiration brought about by the Venturi will create a movement of gas present in the process apparatus, which in moving over the free surface of the liquid will bring about a localized pressure reduction in this area.
The processing gas, after passing over the free surface of the liquid, is saturated with the components removed from same and it will be processed thereafter, in order to separate these components via an exchanger, which cools down the gas and condenses the separated gases, which will be taken outside of the apparatus for subsequent processing. The depleted gas will return to the processing apparatus and be used again as the processing gas, perhaps with addition, when necessary, of another processing gas. Any overall pressure rise due to operating abnormality is controlled by a properly calibrated and fast-opening safety valve.
The process of the invention is energy-efficient when compared to the existing alternatives, since it only moves the quantity of gas necessary to obtain a localized partial vacuum, and the processing apparatus does not need to be designed for negative pressures.
The present invention also refers to the devices used to implement the process.
BRIEF DESCRIPTION OF THE DRAWINGS
The characteristics and additional aspects of the invention will be better understood by reading the description of preferred embodiments of the invention, furnished as illustrative but not limiting examples and shown on the attached drawings, in which:
FIG. 1 shows a simplified schematic view in cross section of a processing tank in which the theoretical process of the invention is carried out;
FIG. 2 shows another simplified schematic view in cross section of a processing tank in which the theoretical process of the invention is carried out;
FIG. 3 shows a schematic view in partial cross section of an installation to carry out the process according to the present invention;
FIG. 4 shows a schematic and partial cross sectional view of an installation which includes a hydrocyclone to carry out the process according to the present invention;
FIG. 5 shows a schematic and partial cross sectional view of a hydrocyclone in which the process according to the present invention is carried out;
FIG. 6 shows a schematic and partial cross sectional view of another installation to carry out the process according to the present invention; and
FIG. 7 shows a schematic and partial cross sectional view of yet another installation to carry out the process according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows one theoretical way of implementing the process according to the invention, in which the crude petroleum with water in emulsion and dissolved gas, that is, the crude petroleum to be processed 2 , is introduced into the closed processing tank 1 where the crude petroleum will be stored, via the inlet pipe 2 a , until the time when it leaves, after processing, via the outlet pipe 8 , in static or dynamic manner (that is, the crude petroleum 2 enters the tank simultaneously with the leaving of the already processed crude petroleum). The processing gas 3 is compressed by a compressor 4 , a current of processing gas 3 being projected, via an injector 4 a , onto and tangentially to the free surface of the crude petroleum, the current of processing gas 3 making a particular angle with the free surface of the crude petroleum before reaching the surface, which can vary between zero and thirty degrees, the angle preferably being between 0 and 8 degrees, but preferably five degrees. In the zone of influence of the current of processing gas 3 there is created a localized zone of reduced pressure 5 on the surface of the crude petroleum. The compressor 4 is fed by the actual gas present in the tank or by a compatible gas arriving from the outside by the pipe 21 , or by a mixture of same.
In the localized zone of reduced pressure 5 , the gas and water in emulsion will separate from the crude petroleum 2 with a speed that depends on the velocity of the processing gas 3 , which creates the localized zone of reduced pressure 5 on the interface with the crude petroleum being stored, and a gaseous mixture 6 is formed, which leaves the tank by the pressure regulating valve 7 , being able to go directly on to further processing or return in whole or in part via a three-way control valve 9 .
The gas above the free surface of the crude petroleum will be maintained at the service pressure prevailing inside the closed processing tank 1 , by the action of the pressure regulating valve 7 and the overpressure rapid relief valve 10 , which is the current practice in the oil industry.
The water separated will drop slowly by gravity to the bottom of the tank and will be drained in usual manner into the storage tanks of the oil industry by the bottom pipe 11 .
The degasified and dehydrated oil will leave the closed processing tank 1 by the outlet pipe 8 for further processing or exporting.
FIG. 2 shows another theoretical way of implementing the process, in which the crude petroleum with water in emulsion and dissolved gas, that is, crude petroleum to be processed 2 , is introduced into a closed processing tank 1 by the inlet pipe 2 a , being sprinkled over a plate 2 b . The crude petroleum is stored until the time it leaves through the outlet pipe 8 , in static or dynamic manner. The processing gas 3 is compressed by a compressor 4 , a current of the processing gas 3 being projected via the injector 4 a onto and tangentially to the free surface of the crude petroleum, the current of the processing gas 3 making a particular angle with the free surface of the crude petroleum on the plate 2 b , before reaching the surface, which angle may vary between zero and thirty degrees, the angle being preferably between 0 and 8 degrees, but preferably five degrees. The compressor 4 is fed by the actual gas present in the tank or by compatible gas coming from the outside, or by a mixture of same.
In the localized zone of reduced pressure 5 , the gas and water in emulsion will separate from the crude petroleum 2 with a speed that depends on the velocity of the processing gas 3 , which creates the partial vacuum on the interface with the crude petroleum being stored, and a gaseous mixture 6 will be formed, which will leave the tank 1 by the pressure regulating valve 7 , being able to go directly on to further processing or return in whole or in part via a three-way control valve 9 .
The gas above the free surface of the crude petroleum will be maintained at the service pressure prevailing inside the closed processing tank 1 , by the action of the pressure regulating valve 7 and the overpressure rapid relief valve 10 , which is the current practice in the oil industry.
The water separated will drop slowly by gravity to the bottom of the tank and will be drained in usual manner into the storage tanks of the oil industry by the bottom pipe 11 .
The degasified and dehydrated oil will leave the closed processing tank 1 by the outlet pipe 8 for further processing or exporting.
FIG. 3 shows in schematic fashion a processing installation for dehydration and degasification of crude petroleum with water in emulsion and dissolved gas, that is, crude petroleum to be processed 2 , which is introduced into the closed processing tank 1 by the inlet pipe 2 a . The crude petroleum 2 is compressed by a pump 2 c , goes through a flexible articulated tube 2 d and is sprinkled over a plate 2 b , both the plate and the flexible articulated tube 2 d being supported in a float 16 , which makes it possible to follow the changes in level in the closed processing tank 1 . The crude petroleum, once processed, is stored until the time of its leaving via the outlet pipe 8 , in static or dynamic manner.
The processing gas 3 is compressed by a compressor 4 , a current of the processing gas 3 being projected via the injector 4 a onto and tangentially to the free surface of the crude petroleum, the current of the processing gas 3 making a particular angle with the free surface of the crude petroleum above the plate 2 b , before reaching the surface, which angle can vary between zero and thirty degrees, the angle being preferably between 0 and eight degrees, but preferably five degrees. The injector 4 a is also joined and connected to the plate 2 b , so that it can follow the level of the crude petroleum in the tank 1 .
The compressor 4 is fed by the gas present in the tank after it circulates through the exchanger 14 , with addition, adding if necessary, of compatible gas 21 coming from the outside. The exchanger 14 receives the gaseous mixture 6 through the pipe 14 a , which is cooled by an outside refrigerant 15 . The condensates of the exchanger 14 are sent on through the pipe 19 for subsequent processing, while the gas coming from the exchanger 14 is aspirated by the compressor 4 and supplied to the tank, its being possible to add, as already mentioned, when necessary, a compatible gas 21 coming from the outside, or if the gas liberated in 5 is excessive, this excess can be exported for subsequent processing.
One can also provide for a heating of the plate 2 b , by a heat exchanger 17 , which will accelerate the processing and, thus, the separation of the water in emulsion and dissolved gases. The heat exchanger 17 is supplied with an outside heating fluid 18 .
The gas above the free surface of the crude petroleum will be maintained at the service pressure prevailing inside the closed processing tank 1 , by the action of the pressure regulating valve 7 and the overpressure rapid relief valve 10 , which is the current practice in the oil industry.
The water separated will drop slowly by gravity to the bottom of the tank and will be drained in usual manner into the storage tanks of the oil industry by the bottom pipe 11 .
The degasified and dehydrated oil will leave the closed processing tank 1 by the outlet pipe 8 for further processing or exporting.
FIG. 4 shows in schematic fashion a processing installation for dehydration and degasification of crude petroleum with water in emulsion and dissolved gas, that is, crude petroleum to be processed 2 , which is introduced into the closed processing tank 1 by the inlet pipe 2 a , the crude petroleum 2 being compressed by the pump 2 c , via the pipe 2 d going to a hydrocyclone 1 A.
The outer wall of the hydrocyclone 1 A can be heated by any adequate device.
The centrifugal force inside the hydrocyclone 1 A will cause the crude petroleum to be dispersed in a truncated conical surface 3 b . The processing gas 3 is compressed by a compressor 4 , having an injector 4 a , with an annular outlet surface, which latter projects a current of the processing gas 3 onto and tangentially to the free surface of the crude petroleum 2 , which makes a particular angle with it, before reaching the surface, which angle can vary between zero and thirty degrees, the angle preferably being between 0 and 8 degrees, but preferably five degrees. A localized zone of reduced pressure 5 is than created, where the subsequent separation of the water in emulsion and the gas dissolved in the petroleum will take place.
The processing gas 3 , which creates the localized zone of reduced pressure 5 , together with separated hydrocarbons and/or evaporated water, forms the gaseous mixture 6 .
The exchanger 14 receives the gaseous mixture 6 directly from the hydrocyclone 1 A, which is cooled by an outside refrigerant 15 . The condensates of the exchanger 14 are taken by the pipe 19 for subsequent processing. The gas coming from the exchanger 14 is taken by the pipe 20 to the tank 1 , its being possible to add, if necessary, compatible gas 21 coming from the outside, or it can be exported for subsequent processing (three-way valve 9 ). This gas repeatedly will continue its compression process through the compressor 4 and it will return to the hydrocyclone 1 A.
The degasified and dehydrated oil will leave the hydrocyclone 1 A through the outlet pipe 12 and return 12 a to the closed processing tank 1 , from which it will leave by the outlet pipe 8 for further processing or exporting or it will go on directly for subsequent processing or export 12 b.
The gas above the free surface of the crude petroleum will be maintained at the service pressure prevailing inside the closed processing tank 1 , by the action of the pressure regulating valve 7 and the overpressure rapid relief valve 10 , which is the current practice in the oil industry.
If there is any water separated by gravity within the tank, it will fall slowly by gravity to the bottom of the tank and it will be drained in customary fashion into the storage tanks of the oil industry, by the bottom pipeline 11 .
FIG. 5 shows in schematic fashion a processing installation for dehydration and degasification of crude petroleum with water in emulsion and dissolved gas, that is, crude petroleum to be processed 2 , which is introduced into a hydrocyclone 1 A, such as that shown in FIG. 4 , but the hydrocyclone 1 A being an independent piece of equipment, that is, in this embodiment the closed processing tank 1 was eliminated, everything else being as described for the embodiment of FIG. 4 as regards the functioning of the hydrocyclone 1 A.
The dehydrated and degasified oil will leave the hydrocyclone 1 A via the outlet pipe 12 for further processing.
FIG. 6 shows schematically a processing installation including a three-phase separator, for dehydration and degasification of crude petroleum with water in emulsion and dissolved gas, that is, the crude petroleum to be processed 2 , in which, according to the background art, the crude petroleum 2 is introduced into the closed processing tank 1 by the inlet pipe 2 a , the crude petroleum moving through the zone 2 e as far as the retention plate 2 f , where the crude petroleum thanks to its lesser density will go on to the part 2 g of the separator, leaving by the outlet pipe 8 . The water, thanks to its greater density, will go to the bottom of zone 2 e , from which it will exit by the bottom pipe 11 . The dissolved gas will be separated slowly and will exit by the bottom pipe 11 . In order to adapt this installation for implementation of the process per the present invention and to make more efficient and rapid the separation of the liquids in emulsion and dissolved gases, there were added to this installation a compressor 4 , an injector 4 a , a three-way control valve 9 .
The current of the processing gas 3 , compressed by the compressor 4 , is projected by the injector 4 a onto and tangentially to the free surface of the crude petroleum, the current of the processing gas 3 making a particular angle with the free surface of the crude petroleum before reaching the surface, which angle can vary between zero and thirty degrees, the angle being preferably between 0 and 8 degrees, but preferably five degrees. The compressor 4 is fed by the actual gas present in the tank 1 or by compatible gas coming from outside 21 . The selection occurs by the three-way control valve 9 . In the zone of influence of the current of the processing gas 3 there is generated a localized zone of reduced pressure 5 above the surface of the crude petroleum.
In the localized zone of reduced pressure 5 , the gas and water in emulsion will separate from the crude petroleum 2 with a speed that depends on the velocity of the processing gas 3 , which creates the partial vacuum on the interface with the crude petroleum being stored, and a gaseous mixture 6 will be formed, which will leave the tank by the pipeline 20 for further processing. The petroleum will also be separated more rapidly from the water, due to the creation of the localized partial vacuum. The gas above the free surface of the crude petroleum will be maintained at the service pressure prevailing inside the closed processing tank 1 , by the action of the pressure regulating valve 7 and by the overpressure rapid relief valve 10 , which is current practice in the oil industry.
FIG. 7 shows in schematic fashion a processing installation for dehydration and degasification of crude petroleum with water in emulsion and dissolved gas, that is, crude petroleum to be processed 2 , which is introduced into the closed processing tank 1 by the inlet pipe 2 a , being then dispersed on a plate 2 b , as it enters the tank. The crude petroleum is stored until the time it leaves through the outlet pipe 8 , in static or dynamic manner.
There is then created by the intake nozzle 13 a of a venturi 13 a localized zone of reduced pressure 5 on the free surface of the crude petroleum 2 , dispersed on the plate 2 b , the outside gas 21 being used as driving fluid in the venturi to bring about the aspiration responsible for the localized zone of reduced pressure 5 . The outside gas can be supplied from some of the process gas present in the tank 1 after its recycling through the exchanger 14 via the pipe 20 and the three-way valve 9 .
The processing gas, after going through the aspiration zone of the venturi 13 a , entrains the gaseous mixture 6 formed by the liberation of the gas dissolved in the crude petroleum and the gas present in the closed processing tank 1 . The gaseous mixture 6 goes on to the exchanger 14 . The exchanger 14 receives a gaseous mixture 6 via the pipeline 13 b , which is cooled by an outside refrigerant 15 . The condensates of the exchanger 14 are sent on through the pipe 19 for subsequent processing, while the gas 3 coming from the exchanger 14 is supplied to the tank 1 . If necessary, depending on the volume of gas liberated in 5 , part of the gas returned to the tank will be recirculated entirely or partially by the compressor 4 via the pipeline 20 and the three-way valve 9 a or it can be exported in whole or in part for subsequent processing 20 a.
The gas above the free surface of the crude petroleum will be maintained at the service pressure prevailing inside the closed processing tank 1 , by the action of the pressure regulating valve 7 and the overpressure rapid relief valve 10 , which is the current practice in the oil industry.
The water separated will drop slowly by gravity to the bottom of the tank and will be drained in usual manner into the storage tanks of the oil industry by the bottom pipe 11 .
The degasified and dehydrated oil will leave the closed processing tank 1 by the outlet pipe 8 for further processing or exporting.
There are described above embodiments which are considered most illustrative of the invention, although modifications are clearly possible, it being possible, for example, in the embodiment of FIG. 3 , for the crude petroleum 2 to be dispersed directly onto the plate 2 b , or in the embodiment of FIG. 7 the plate 2 b can be mounted in a float, the aspiration nozzle 13 a can be connected to its respective pipe and to the plate 2 b , so as to follow the change in level of the petroleum within the tank 1 , and the inlet pipe 2 a for the crude petroleum 2 can be flexible and be connected to the plate 2 b so that it can also follow the change in level of the petroleum within the tank 1 .
Without departing from the scope of the invention, it is possible for a materials expert to realize all the modifications and improvements suggested by normal experience and the natural progress of engineering, in the process and device for implementing of the process of the present invention. | A process and a device implementing the process, for separating fluids in emulsion and/or in solution, and/or for low pressure distillation, in particular of water and/or gaseous hydrocarbons dissolved in crude petroleum, and/or for separation of crude petroleum droplets emulsified in water, to obtain water with necessary characteristics for its injection without pollution of underground aquifers, and/or when the mixture is dominant in crude petroleum, acceleration of settling of the water in the lower part of the mixture, and/or for low pressure distillation of crude petroleum. The method creates a localized zone of reduced pressure on part of the free surface of a liquid to be processed, within a closed processing tank, without the overall pressure inside the closed processing tank being affected. | 1 |
This is a continuation of application Ser. No. 08/628,036 filed Apr. 4, 1996, now U.S. Pat. No. 5,666,698.
BACKGROUND OF THE INVENTION
The area of technical application of the invention is that of textile machines. In this area, the machine involved is in particular a draw frame with calendar equipment following the drafting equipment, consisting usually of two calendar disks facing each other by means of which the fiber sliver is compressed. Both are described in DE 295 10 871 U1 of Jul. 5, 1995. This patent refers to the full contents of this patent application.
As a rule several fiber slivers are doubled into one single fiber sliver before the drafting equipment. The doubled fiber sliver is conveyed into the drafting equipment. During the drafting process, the fiber sliver is spread out into a fiber fleece and is conveyed in this condition from by the pair of delivery rollers of the drafting equipment. The fiber fleece must be formed again into a fiber sliver. This is done by means of the fleece funnel. As the fiber fleece enters the inlet of the fleece funnel, a fiber sliver is formed again.
In the state of the art it is known that a pair of delivery rollers is provided at the output of drafting equipment of a draw-frame (e.g. a fiber processing machine) which conveys this fiber fleece into a fleece funnel. The fiber fleece is gathered together in the fleece funnel and is formed back into a fiber sliver and is conveyed to a fiber sliver channel having a considerable length. At the end of the fiber sliver channel, the fiber sliver is introduced into a fiber sliver funnel which deflects the direction of travel of the fiber sliver by approximately 90° and introduces it between a pair of calendar rollers (calendar disks). Once the fiber sliver has run through the pair of calendar rollers, the fiber sliver which has been compressed therein is conveyed on to the depositing device of the draw frame (see also e.g. EP 593 884 A1, U.S. Pat. No. 4,372,010 or DE-A, 26 23 400).
In DD 290 679 the fleece funnel and the sliver funnel are at a considerable distance above a fiber sliver channel. A venting opening (13 therein) allows the air which flows in at the beginning of the collection channel (therein 5) to escape completely before the narrowest point of the sliver funnel in order to build up again a suction stream shortly thereafter which is built up with inflowing compressed air by an injection bore in the fleece channel segment with the smallest diameter.
OBJECTS AND SUMMARY OF THE INVENTION
The invention has as a principal object to bring the beginning of the fiber fleece automatically into the fiber sliver channel between the delivery rollers and the calendar disks and to deposit it directly in front of the nip of the calendar disks, in particular in a manner that is economical of the conveying air. Additional objects and advantages of the invention are set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
The process according to the invention avoids lateral escape of an air stream which is conveyed in the lateral air-tight guiding channel through at least two nozzle segments of the fiber sliver guiding system. The conveying air which is conveyed free of loss is produced via injection bores which are provided in the cylindrical segment of the sliver funnel, shortly before the nip of the calendar disks, whereby the above-mentioned cylindrical segment merges into a pointed end of the sliver funnel which is located immediately before the nip. The diameter of the cylindrical segment is here considerably smaller than the width of the calendar disks which are calendaring the fiber sliver fed to them.
Hereinafter mention is made of a pair of calendar disks or of the calendar disks, and this term also covers a pair of calendar rollers. This is possible because the invention excludes neither a pair of calendar disks nor a pair of calendar rollers.
The diameter of the cylindrical segment may be less than one third of the width of the calendar disks or, expressed differently, the calendar disks are at least three times wider than the diameter of the narrowest segment of the sliver funnel.
The process functions with a closed nip as well as with an open nip.
In order to enable the sliver funnel and its guiding channel to be placed very close to the nip, the forward end tapers to a point and ends in a line; curved surface segments of the forward end of the sliver funnel which are adapted to the curvature of the surface of the calendar disks also end in this line. The pointed end can correspond to the width of the nip.
Faster and more reliable preparation is ensured through the invention due to the elimination of the long fiber sliver channel of the state of the art, so that the fleece funnel and sliver funnel can be installed directly one after the other. This is the guiding system.
It now becomes possible to accelerate and simplify preparation, i.e. the introduction of the drafted fiber sliver, and to reduce air losses as much as possible. Thanks to the elimination of the fiber sliver channel, the fiber sliver guiding system according to the invention becomes particularly short and compact. Long distances, and thereby technologically undesirable dead times, can be reduced. In spite of its compact construction, the fiber guiding system is easy to handle and even allows for two positions of the interlocking nozzles via the air-tight articulation, one for normal operation and one for preparation. Surprisingly, the compact fiber sliver guiding system can be adjusted easily and is maintenance and service friendly. In spite of the compact construction of the guiding system, it is possible to replace the nozzle inserts in order to make rapid change-over possible in case of a batch change.
The nearly totally loss-free air conveying process from fleece funnel to in front of the nip of the calendar disks is characteristic for the air-guided automatic introduction of the fiber fleece into the fiber sliver guiding channel of the textile machine. The air is conveyed without losses from the fleece funnel (which rolls together the drafted fiber fleece and gathers it) to the sliver funnel (which causes the fiber sliver to be compacted before the pair of calendar rollers). In this area, no lateral opening from which the air could escape is made in the guiding channel; in this area only lateral inflow bores (injection bores) which generate and maintain the air suction stream are present.
Because of the air conveying system which is closed up to the nip, the process for automatic introduction of the beginning of the fiber fleece is very economical in air. At the same time, the process is not sensitive to pressure fluctuations of the air used for the introduction and is able to work reliably within a wide range of compressed air.
Slanted introduction in the direction of fiber sliver movement causes the compressed air to become a suction stream on top.
Mechanical threading of a segment of the fiber fleece into the fleece funnel is entirely omitted. The fiber fleece merely has to be reduced to a smaller width at its forward end and the remaining, narrower segment has to be shortened to a predetermined length determined by the weight of the fiber fleece and the length of the fiber channel and the fleece channel from the fleece funnel to the nip. Brief actuation of a compressed-air generator in order to generate a brief compressed-air impulse produces the threading of the narrowed segment of fiber fleece into the fleece funnel and the conveying of this segment before the nip, where a brief rotational impulse of the calendar disks causes the complete threading or the complete introduction of the fiber sliver between the calendar disks.
The compressed-air impulse can be advantageously coupled with a rotational impulse that is slightly offset in time so that the operator needs to depress the push button only once in order to thread the fiber fleece. In the state of the art, a fiber fleece cannot be presented, introduced and be brought into operating position any more easily, rapidly and reliably.
The suction air stream above the point of compressed-air intake is reliably created when the compressed air is introduced at the point of the fiber sliver conveying channel with the smallest diameter. This is the sliver funnel which is installed in close proximity of the calendar disks. A stream of compressed air fed at this point in the direction of the calendar disks reliably produces a suction air stream above the feed point and going up to the fleece funnel, as no air losses occur there. No openings at a right angle to the guiding channel are provided in the entire guiding segment going from the fleece funnel to the sliver funnel which could make it possible for air to escape. The reliable build-up of the suction air stream starting at the forward end of the conveying path and taking effect back to the point of entry of the spread-out fiber fleece--the fleece funnel--makes it possible to avoid the necessity of bringing any additional air flow into this area, as is normally the case in the state of the art, when an inflow of air is provided at the fleece funnel or directly thereafter, while venting is provided at the sliver funnel or directly thereafter.
With the present invention the fiber fleece is thus taken up at its forward end by the air stream and is then pulled in the form of a fiber sliver along the entire fiber sliver channel and is presented directly in front of the calendar disks. The fiber sliver is not "pushed" by compressed air and is de-aired far before the calendar disks.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows the usual configuration of a fiber sliver guiding system with a long fiber sliver channel (left side of drawing) superimposed on a compact construction according to the invention (right side of drawing) with two nozzle inserts 30, 40, 50 60 connected together, of which two nozzle inserts 40, 50 are able to tilt relative to the other two nozzle inserts 30, 60 which are located on a nozzle holder 20 fixedly installed above the calendar disks 100a,100b. The superimposed drawing serves to illustrate the shortening of the conveying distance. The deflection roller 71 is part of the compact construction shown on the right side of the drawing;
FIG. 2 shows a fiber sliver guiding system according to the state of the art;
FIG. 3 shows the preparation of the fiber fleece F for introduction into the fleece funnel 50;
FIGS. 4a, 4b and 4c show an enlargement of the sliver funnel 30 of FIG. 1 which feeds the air without losses to a point directly at the nip 100c;
FIGS. 5a and 5b show the swiveling of a fleece funnel with nozzle insert 40' and a calendar disk 100b around a common pivot point SP.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the presently preferred embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the invention without departing from the scope or spirit of the invention.
The superimposition of FIG. 1 shows the difference with the state of the art which is shown schematically in FIG. 2. The fiber sliver FV which is not yet drafted when it is introduced is introduced in the state of the art via drafting rollers 68a, 68b, 69a, 69b and delivery rollers 70a, 70b by means of a fleece funnel 1 into a long guiding channel 8 which lets out in a sliver funnel 9. The sliver funnel deflects the fiber sliver FB by approximately 90° and into the nip of the calendar with its calendar disks 100a, 100b. The calendared fiber sliver KF emerges from the calendar in a vertically downward direction and is stored in a depositing device. This fiber sliver guidance is also shown with the same reference numbers in FIG. 1.
An embodiment of the invention shortens the fiber sliver path and makes it possible to omit the fiber sliver channel 8. An additional deflection roller 71 is used which deflects the direction of travel of the fleece FV by approximately 60° and introduces the fiber sliver into a device consisting of several functional elements forming the fiber sliver channel. The first element is the fleece funnel 50 with a ramp surface 50b and an immediately following funnel section 50a in which the wide, arriving fiber sliver (also called a fiber fleece) folded, doubled and is introduced into a first channel section. The channel section is constituted by an insert 40 which is plugged in on the rear side of the funnel segment 60 and is attached with a screw.
An articulation surface is provided at the forward end of insert 40 and, in the corner position shown in FIG. 1, it makes possible sealing off the guiding channel against the downstream sliver funnel 30.
The articulation surface of the forward, cylindrical segment of the inner insert 40 consists of two constantly curving surface segments tapering towards the rear which engage a matching bearing surface 35 on sliver funnel 30. Swiveling the fleece funnel 50 in direction α into the other end position does not break the radial air-tight seal between fleece funnel and sliver funnel, and air-tight air fiber sliver conveying is obtained in the closed as well as open, swiveled state.
The radial tightness on the articulation surfaces 35 is adjustable. The upper part--above the articulation surface--can be modified for this in axial direction, in particular also in radial direction in its relative position to the lower part. The fixed holder 20 in which the sliver funnel is inserted constitutes the basis for adjustment.
If the fleece funnel 50 is made in two parts--with the insert inserted into the funnel bore of the fleece funnel in a direction opposite to that of fiber sliver movement--the previously mentioned relative adjustment can be made on a grip 51.
The sliver funnel 30 is made in the form of an insert and reaches with a pointed tapered V-shaped end between the calendar disks 100a, 100b directly to the nip 100c. The insert 30 is configured so that it can be inserted axially into a sliver funnel holder 60 and be held there.
The fiber sliver is conveyed through the fleece nozzle 50, the inner insert 40 and the sliver funnel 30 into the guiding channel up to nip 100c, and for this the fleece 50 is swiveled out. The manually narrowed fiber fleece part F1 is held into the funnel opening 50a and is sucked in via injection bores 34a, 34b, 64a, 64b on the sliver funnel. A brief suction stream of a magnitude in time of approximately 500 m/sec is sufficient in order to convey the narrowed fiber sliver F1 with a minimal expenditure of compressed air until it is in front of the nip 100c, since the articulation bearing surface 35 and the bearing surface of the inner insert 40 are radially sealed off. Mechanical insertion assistance is not required.
In order to introduce first the segment F1 of the fiber fleece, and with it the full width F of the fiber fleece, through the nip in the form of an reshaped fiber sliver, a brief rotational impulse is imparted the calendar disk. It is able to shut itself off automatically after a predetermined suction time, may be superimposed on it, or can be shut off separately, manually.
The form of the sliver funnel 30 is clearly shown in FIG. 4a, and the direction and placement of the injection bores 34a, 34b in the sliver funnel are also shown in enlarged form here. The bores let out into a cylindrical channel 31 constituting the forward end of the fiber sliver channel. The cylindrical segment 31 widens over a conical segment 32 to the diameter of the fiber sliver channel which is determined by the inner insert 40.
The slanted injection bores 34a, 34b may form an angle of approximately 45° with the axis 200b of the sliver funnel insert 30, and they may be parallel-offset in order to impart a twist to the introduced fiber sliver as well as additional strength.
A sliver funnel holder 60 is provided with a centered, approximately cylindrical opening into which the sliver funnel insert 30 is inserted. An annular channel 33 open to the inside extends in circumferential direction in the cylindrical opening and can be supplied with compressed air by two or more cylindrical bores 64a, 64b. Extending from the annular channel, the compressed air introduced from the outside is introduced into the previously mentioned slanted injection bores 34a, 34b when the sliver funnel insert 30 is inserted and lets out in the cylindrical segment 31 of the fiber sliver channel which is located immediately against the nip 100c.
The forward end of insert 30 is V-shaped and has slightly curved V legs which are adapted to the surface curvature of the calendar rollers 100a, 100b. The sliver funnel insert 30 can thus be inserted directly into the slightly curved, narrowing intermediate space between the calendar disks and the cylindrical segment 31 ends with its forward end directly in front of the nip 100c. This becomes especially clear in the side view of FIG. 4c. The diameter d of the cylindrical guiding channel 31 is shown here. The forward, cylindrical segment of the sliver funnel insert 30 is provided here with two surface segments 31a, 31b which taper laterally in an upward direction and have the curvature shown in FIG. 4a. A V shaped opening end results in function of the pointed tapered sliver funnel insert 30 and the cylindrical bore 31 with constant diameter, whereby the air flowing through the injection bores emerges from this opening and conveys the fleece up to the nip.
Because of the width b of the calendar disks in relation to the clearly smaller diameter d of the cylinder guiding channel, the air cannot or only barely or slowly escapes laterally, so that the major portion of the flowing air is conveyed up to the nip and deposits the fiber fleece it carries along at that point.
FIG. 4b shows a top view in which the width b of the two calendar disks 100a, 100b can be seen. Also shown are the injection bores 64a, 64b as feed channels going to the annular channel 33, as well as the parallel-offset, slanted injection channels 34a, 34b in insert 30. At least 2 injection channels are present, so that the fiber sliver is centered and is at the same time imparted a twist.
The compressed air can be used at a pressure of 4 bar, for example, but is adapted to a channel diameter of approximately 3.8 mm in the sliver funnel and approximately 8 mm in the insert 40 of the fleece funnel 50. Tests have shown that even a compressed air blast of approximately 500 m/sec duration is sufficient for secure introduction of the forward end F1 of the fiber sliver up to the nip 100c. The length H1 of the manually narrowed fiber fleece is here adapted to the distance between the fleece funnel 50 and the nip 100c, and thereby to the length of the air-tight fiber sliver channel.
The above-mentioned annular channel 3 may also be made on the insert 30, e.g. by a surrounding notch, in an alternative variant (not shown in the drawings).
FIG. 5a shows a fleece funnel 50 with a nozzle insert 40'. The insert 40' is made in one piece. The insert 40' has a fiber sliver guiding system designed so that it corresponds in a first segment to the fiber guiding system of an insert 40 and in the following segment to the fiber sliver guiding system of a sliver funnel 30 (as in FIG. 4a). FIG. 5a shows such an insert 40' in preparation position, i.e. in a position for the presentation of the fiber fleece into the funnel area 50a. This position shown in FIG. 5a is also assumed by the insert 40' when a backup of fiber fleece has occurred.
The insert 40' can be replaced much quicker than the insert 40 and the sliver funnel 30 as shown in FIG. 1. Readjustment or alignment tasks can be omitted because of the compact (one-piece) configuration of the insert 40'. Furthermore no air-tight swiveling articulation is necessary.
In an advantageous embodiment, a calendar disk 100b and the insert 40' are located in a common support or holder (not shown). The support swivels around a pivot point SP. It is possible to swivel the calendar disk 100b and the insert 40' around the common pivot point SP. Since insert 40' is connected to the fleece funnel 50, both are therefore swiveled. For the sake of simplification only swiveling of insert 40' is mentioned hereinafter. Swiveling provides better access to the operator and allows him to see the insert 40' better. A conveyed fiber fleece can therefore be presented manually in the funnel area 50a in order to thread the beginning of the fiber fleece. The fiber fleece is formed by the fleece funnel into a fiber sliver and is immediately conveyed between the open calendar disks 100a, 100b. For the beginning of stationary operation the insert 40' and the calendar disks 100a, 100b are swiveled back into position as shown in FIG. 5b. This is the position for stationary operation (operating position) of insert 40'.
Another embodiment makes it possible to swivel insert 40' separately and to swivel the calendar disk 100b separately around pivot point SP. This allows the calendar disk 100b to remain in closed position during sliver introduction. Only the insert 40' swivels for the introduction of the sliver start. If it is necessary to open the calendar disks, this can be done separately.
It is also possible to have an embodiment in which the insert 40' does not swivel but is fixed as shown in FIG. 5b. In such a design, the guiding surface LF of the fleece funnel 50 must be pivotable. A pivot axis must be advantageously provided in the lower area of the guiding surface so that said guiding surface LF can be swiveled away only from the funnel area 50a. This makes it possible to swivel guiding surface LF away in case of fiber fleece back-up, so that said fleece is able to move out of the funnel area 50a. Furthermore, the operator is afforded a view of the funnel area 50 thanks to the ability of guiding surface LF to swivel. In this embodiment, a calendar disk 100 can furthermore be supported so as to be able to swivel relative to a pivot point SP.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit of the invention. For example, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. It is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. | A process and device are provided to introduce a fiber fleece through the nip of a pair of calendar rollers. Pressurized air is directed to a cylindrical segment of a sliver guiding system down stream from a tapered conical section so that the pressurized air draws the fiber fleece through the sliver guiding system without requiring lateral venting or expansion of the pressurized air. The pressurized air vents from the front end of the cylindrical section adjacent the nip of the pair of calendar rollers. | 3 |
FIELD
[0001] This disclosure relates generally to a spin-on filter for use in fluid, for example oil or fuel, filtration that is configured for attachment to a mounting head without the use of a nut plate commonly used on filters of this type.
BACKGROUND
[0002] Typical spin-on fluid filters according to some prior art designs are mounted to the mounting head by the use of an internally-threaded metal nut plate. The nut plate is anchored to the filter shell and includes at least one flow inlet and a flow exit. A spin-on filter with a nut plate often includes a large number of components that are required to form the filter which increases the cost and assembly complexity of the filter.
[0003] Some known spin-on fluid filters eliminate the nut plate. Examples include U.S. Pat. Nos. 7,434,697 and 7,614,504.
[0004] Whether or not the spin-on filter includes a nut plate, sealing must be provided between the head and the filter to prevent leakage outside the filter to environment, and sealing must be provided between the flow inlet and the flow exit to prevent leakage of unfiltered fluid from the inlet to the filtered fluid outlet. These sealing functions are typically provided by separate parts of the filter, including the use of installed sealing gaskets.
[0005] Improvements to spin-on filters are desirable.
SUMMARY
[0006] A spin-on filter is described that eliminates the use of a nut plate and reduces the number of separate components. Instead, the spin-on filter utilizes the top end plate of the filter cartridge to perform a number of functions, including closing the open end of the filter shell, sealing between the dirty and clean fluid sides, sealing between the filter and the mounting head to prevent leakage outside the filter to environment, attaching the filter cartridge to the shell, and sealing the end of the filter media.
[0007] The filter is less expensive to fabricate, including cost savings by eliminating many of the components found in traditional spin-on filters. The reduced number of components also helps to reduce the weight of the filter. In addition, by integrating the multiple functionalities in the top end plate, separate sealing gaskets are avoided while providing a unique interface design. Also, eliminating the nut plate allows more space availability at the top of filter which can be utilized for maximized slit width or compact filter design.
[0008] In one embodiment, the spin-on filter includes a shell having a closed end and an open end. The shell includes threads adjacent the open end that are configured to connect the shell to a mounting head. A filter cartridge is disposed within the shell that includes filter media suitable for filtering a fluid, including but not limited to oil or fuel such as diesel fuel. An end plate is attached to the filter media and is positioned adjacent to and closes the open end of the shell. The end plate has a perimeter edge that is attached to an end of the side wall of the shell which fixes the cartridge to the shell, a central fluid passageway in fluid communication with an inner space of the filter media, and a plurality of fluid passageways positioned between the perimeter edge and the central fluid passageway that are in fluid communication with the interior space of the shell. The end plate can also include first and second seals that are integrally formed therewith. The first seal is located adjacent to and is circumferentially continuous around the central fluid passageway to enable sealing with the mounting head to seal dirty fluid entering the filter from filtered fluid exiting the filter. The second seal is located adjacent to the perimeter edge and is circumferentially continuous on the end plate to enable sealing with the mounting head to prevent fluid leakage between the filter and the mounting head.
[0009] The various functions of the end plate of the filter cartridge discussed above can be used separately from one another or in any combination of the functions. For example, the end plate can close the open end of the filter shell and can be used to attach the filter cartridge to the shell, but sealing is provided by seals other than seals integrally formed on the end plate. In another example, the end plate can include integral seals for sealing between the dirty and clean fluid sides and sealing between the filter and the mounting head to prevent leakage outside the filter to environment, and the end plate can substantially close the end of the filter shell, but the cartridge can be fixed to the shell in a manner other than by using the end plate. Other combinations of functions are possible for the end plate.
[0010] The end plate can be formed of any material that is suitable to permit the first and second seals to perform their intended sealing functions. For example, the end plate can be formed of plastisol, polyurethane, a plastic with polyurethane, or other plastic material.
[0011] The perimeter edge of the second end plate can be attached to the shell in any manner that is suitable for fixing the cartridge to the shell. The attachment can be detachable to permit replacement of the filter cartridge, or permanent in which case the entire filter will be disposed of. Examples of attachments include, but are not limited to, a snap fit connection between the perimeter edge and the shell, spin welding the side wall of the shell to the perimeter edge, or molding the perimeter edge with the end of the side wall of the shell.
[0012] The threads used to connect the filter to the mounting head can be exterior threads or interior threads. The threads can be integrally formed on the side wall or can be formed on an attachment cap that is disposed adjacent to the open end of the shell and that is rotatable relative to the shell.
[0013] The improved spin-on filter described herein has two main subassemblies, namely the filter cartridge and the shell. In addition, the top end plate of the filter cartridge is configured to perform a number of functions, many of which were performed by separate components in prior spin-on filter designs. Therefore, the number of component parts of the filter is reduced compared to prior spin-on filter designs, which reduces cost. In addition, using the top end plate to close the open end of the shell permits an increase in filter media area that can be used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates an embodiment of the improved filter described herein in position to be mounted to a mounting head.
[0015] FIG. 2 is a cross-sectional view of the filter of FIG. 1 mounted to the mounting head.
[0016] FIG. 3 is close-up view of the portion contained in box 4 in FIG. 2 .
[0017] FIG. 4 is a partial sectional view of the filter of FIG. 1 .
[0018] FIG. 5 is a cross-sectional view of the filter of FIG. 1 showing the increase in slit width and pleat depth.
[0019] FIG. 6 is a close-up view of the portion contained in box 5 in FIG. 5 .
[0020] FIG. 7 is close-up view of the portion contained in box 6 in FIG. 5 .
[0021] FIG. 8 illustrates the underside of the filter head.
[0022] FIG. 9 illustrates another embodiment of an improved filter described herein mounted to a mounting head.
[0023] FIG. 9A is a close-up view of the portion contained in box 9 A in FIG. 9 .
[0024] FIG. 9B is a close-up view similar to FIG. 9A , but taken through one of the inlet openings in the end plate.
[0025] FIG. 10 illustrates another embodiment of an improved filter described herein mounted to a mounting head.
[0026] FIG. 11 is a close-up view of the portion contained in box 8 in FIG. 10 .
[0027] FIG. 12 illustrates another embodiment of an improved filter described herein mounted to a mounting head.
[0028] FIG. 13 is a close-up view of another embodiment of sealing between the head and the filter.
[0029] FIG. 14 illustrates another embodiment of an improved filter described herein mounted to a mounting head.
[0030] FIG. 15 illustrates a cap used to mount the filter of FIG. 14 to the head.
[0031] FIG. 16 illustrates another embodiment of an improved filter described herein mounted to a mounting head.
[0032] FIG. 17 illustrates another embodiment of a cap used to mount the filter of FIG. 16 to the head.
[0033] FIG. 18 illustrates an improved filter described herein next to a prior art filter using a nut plate in FIG. 19 .
DETAILED DESCRIPTION
[0034] With reference initially to FIGS. 1-7 , a spin-on fluid filter 10 in accordance with one embodiment is illustrated. The filter 10 is configured for detachable connection to a filter mounting head 12 . As used herein, the term spin-on refers to the use of rotation to effect connection and disconnection of the filter 10 to and from the head 12 . However, it is believed that the concepts described herein can be applied to other forms of connection between the filter and the head that do not require rotation.
[0035] The fluid filter 10 will be described herein as being configured for filtering oil or fuel such as diesel fuel. However, it is contemplated that the concepts described herein can be utilized on filters that filter others types of fluid, including liquids such as water, and air. In addition, the filter will be described as being configured for outside-in flow of the fluid where the fluid flows generally radially inward through the filter media to a central space and then out through a central outlet. However, the concepts described herein can also be employed on a filter that is configured for inside-out flow of fluid where the fluid flows generally radially outwardly through the media during filtration.
[0036] The head 12 includes an inlet 14 for dirty fluid to be filtered by the filter 10 , and an outlet 16 for filtered fluid that has been filtered by the filter. The inlet 14 is in communication with an interior circumferential space 18 , and the outlet 16 is in communication with an outlet space 20 . As shown in FIGS. 1 and 2 , the head 12 includes a circumferential skirt 22 with interior threads 24 formed on the interior thereof for use in connecting to the filter 10 . A circumferentially continuous sealing surface 26 is formed on the interior of the head adjacent the base end of the skirt 22 . In addition, as shown in FIGS. 1 , 2 and 8 , a sealing rib 28 projects downwardly from the interior of the head toward the filter 10 radially inwardly from the sealing surface 26 . The rib 28 has an angled sealing surface 30 that faces generally toward the central axis of the filter. The space 18 is defined between the sealing surface 26 and the rib 28 .
[0037] The filter head 12 is preferably configured to avoid sealing if one attempts to install an incorrect filter. For example, as shown in FIG. 8 , the rib 28 has a plurality of spaced slots 32 provided in it to avoid axial sealing if an incorrectly configured filter is used with the head 12 . In addition, the rib 28 is provided with a plurality of half circular tabs 34 to avoid any radial sealing if an incorrectly configured filter is used with the head 12 .
[0038] Returning to FIGS. 1-5 , the filter 10 has two main subassemblies, namely a shell 40 and a filter cartridge 42 that is disposed within the shell. The shell 40 can be formed of metal which allows the shell to be made thin. However, the shell can be formed of other materials, including plastic, if the shell is able to withstand the operating environment, including bearing loads and pressure, of the filter.
[0039] The shell 40 has an end wall 44 defining a closed end of the shell, and a side wall 46 extending from the end wall. The side wall 46 has an end 48 opposite the end wall 44 that defines an open end of the shell. The end wall 44 and the sidewall 46 define an interior space 50 of the shell between the closed end and the open end which is sized to receive the filter cartridge 42 therein. As best seen in FIGS. 1-5 , the end 48 of the side wall includes exterior threads 52 adjacent the open end that are configured to engage with the threads 24 on the head to connect the filter to the head. In one embodiment, the shell 40 can be an extruded shell with the threads 52 formed by a rolling, spinning or other forming operation as per DIN 7273 standard or with any specific thread profile.
[0040] The filter cartridge 42 includes filter media 60 that is suitable for filtering the fluid with which the filter will be used. One example of a suitable filter media 60 is a pleated cellulose media. However, other types of filter media can be employed including, but not limited to, multiple media layers and non-pleated media. As described further below, the use of pleated media is advantageous since the use of an end plate that closes the open end of the shell permits an increase in the slit width and the pleat depth of the pleated media, which increases the media area. However, similar increases in media area would be achieved with non-pleated media.
[0041] The media 60 is arranged in a generally cylindrical shape and defines an inner space 62 . A plastic or metal center tube 64 is disposed in the inner space 62 and supports an interior surface of the filter media 60 . The center tube 64 has a first end that is potted in the bottom end plate as described below, and a second end 66 that is surrounded by the upper end plate (described further below) and which helps defines a filtered fluid outlet of the filter.
[0042] A first or bottom end plate 70 is attached to a first end of the filter media 60 adjacent to the closed end of the shell. Likewise, a second or upper end plate 72 is attached to a second end of the filter media and is positioned adjacent to and closes the open end of the shell. The end plates 70 , 72 seal the ends of the media 60 to prevent fluid from flowing axially through the ends of the media, so all of the fluid flows generally radially through the media.
[0043] In the illustrated embodiment, the ends of the media 60 are attached to the end plates 70 , 72 using an over molding process where the end plates 70 , 72 are molded around the ends of the media and the ends of the center tube. During molding, each end of the media 60 and center tube 64 assembly is placed in a mold cavity. Polyurethane, plastisol, plastic with polyurethane, or other plastic material potting compound is introduced into the cavity and when cured, the ends of the media and the center tube become intimately bonded with the cured material and forms the end plates 70 , 72 that are integral structures with the media and the center tube.
[0044] However, it is contemplated that the media, center tube and the end plates can be attached in other manners, including by embedding the ends of the media and the center tube into pre-formed endplates, by using an adhesive, or through other suitable attachment means.
[0045] For ease of construction, the end plates 70 , 72 are preferably formed of the same material. However, the end plates 70 , 72 can be formed of different materials if it is necessary or considered beneficial in order to implement the intended sealing functions of the second end plate 72 as discussed further below. The material(s) used to form the end plates can be any material(s) that is suitable to perform the intended functions of the end plates 70 , 72 . For example, the end plates can be formed of plastisol, polyurethane, a plastic with polyurethane, or other plastic material.
[0046] As shown in FIGS. 1-5 , the first end plate 70 is closed which means that there are no fluid passageways therethrough. However, in other embodiments, depending upon the intended function of the filter media, one or more openings could be provided at certain locations in the first end plate 70 , for example to allow separated water to flow to a sump area. Filters designed with a filter-in-filter construction or filters with hydrophobic media designs typically use this type of end plate with openings construction. A plurality of tabs 71 are formed on the bottom of the end plate 70 during the molding operation. The tabs 71 act as stoppers for the cartridge 42 when it is being inserted into the shell 40 . The tabs 71 allow the spring which is normally used in conventional spin on filters to be eliminated. In addition, the tabs 71 also help to locate the cartridge 42 in the shell 40 .
[0047] With reference to FIGS. 4 and 5 , the second end plate 72 includes a perimeter edge 74 that is attached to the end 48 of the side wall of the shell, a central filtered fluid outlet passageway 76 in fluid communication with the inner space 62 , and a plurality of dirty fluid inlet passageways 78 positioned between the perimeter edge 74 and the central fluid passageway 76 in fluid communication with the interior space 50 .
[0048] As shown in FIG. 5 , the second end plate 72 extends across the entire open end of the shell, closing the open end. As best seen in FIGS. 4 and 5 , the perimeter edge 74 is attached to the end 48 by overmolding the second end plate 72 onto the end 48 which fixes the filter cartridge to the shell. Therefore, during the intended use of the filter when it is mounted on the head 12 , the only way for fluid to enter the filter 10 is through the passageways 78 , and the only way for fluid to exit the filter is through the passageway 76 .
[0049] In addition to over molding the end plate 72 onto the end 48 , the end plate 72 is also molded over the second end 66 of the center tube 64 as discussed above. In addition, the first end plate 70 is also over molded the first end of the center tube 64 .
[0050] With reference to FIGS. 2-5 , the second end plate 72 includes a first seal 80 that is configured to seal with the sealing rib 28 to seal dirty fluid entering the filter from filtered fluid exiting the filter, and a second seal 82 that is configured to seal with the sealing surface 26 to prevent fluid leakage between the filter and the mounting head. The seals 80 , 82 are integrally formed with, and formed from the same material used to form, the end plate 72 .
[0051] The first seal 80 is located adjacent to, and is circumferentially continuous around and defines, the central fluid passageway 76 . The first seal 80 includes an angled surface 84 that engages with and seals against the angled surface 30 on the sealing rib as shown in FIGS. 2 and 3 . The second end 66 of the center tube 64 provides support to the seal 80 . Therefore, angular sealing is achieved by compression of the seal 80 between two solid permanent parts of the center tube 64 and the angled surface of the sealing rib 28 . This forms the sealing for the clean and dirty side. This angularity in the sealing also provides alignment and it will also compensate for radial variation due to the threads 52 during assembly of the filter 10 with the head 12 .
[0052] The second seal 82 is located adjacent to or at the perimeter edge 74 and is circumferentially continuous on the second end plate. The second seal 82 is configured to engage and seal against the sealing surface 26 as shown in FIGS. 2 and 3 .
[0053] Use of the filter 10 is as follows. The filter 10 is brought toward the head 12 as shown in FIG. 1 , and then threaded onto the head using the threads 24 , 52 as shown in FIG. 2 . When completely threaded onto the head, the angled surface 84 of the seal 80 seals against the angled surface 30 of the sealing rib 28 , while the seal 82 seals against the sealing surface 26 . If an incorrectly designed filter is installed, the filter will not correctly seal against the angled surface 30 , and the slots 32 and/or tabs 34 on the rib 28 will permit fluid leakage.
[0054] The flow of fluid in the filter is shown by the arrows in FIG. 2 . Fluid to be filtered flows into the head via the inlet 14 , flows into the space 18 , and then flows through the passageways 78 in the end plate 72 into the filter as shown by the arrows. The fluid then flows generally radially inwardly through the filter media, through openings in the center tube and into the inner space 62 . The filtered fluid then flows upwardly through the outlet passageway 76 , into the space 20 and then exits via the outlet 16 .
[0055] FIGS. 9 , 9 A and 9 B illustrate another embodiment of a filter 100 which is similar in many respects to the filter 10 . Therefore, only the differences from the filter 10 will be described in detail, and features that are similar to features in the filter 10 will be designated with the same reference numerals. As shown in FIG. 9 , the head 102 is configured similar to the head 12 with respect to the fluid inlet and the sealing surface 26 .
[0056] The filter 100 primarily differs from the filter 10 with respect to the center tube and fluid outlet design. The second end plate 73 includes a first seal 90 that is configured for radial sealing with an outlet tube 91 of the head while the seal 82 seals against the sealing surface 26 . In addition, the filter 100 includes a center tube 108 where the first end is embedded in the first end plate 70 as in the filter 10 . However, the second end of the center tube 108 is simply potted into the second end plate 73 at a location between the seal 90 and the seal 82 as best seen in FIGS. 9A and 9B .
[0057] As shown in FIGS. 9A and 9B , the perimeter edge 74 of the end plate 73 is attached to the end 48 of the shell by overmolding the second end plate 73 onto the end 48 which fixes the filter cartridge to the shell.
[0058] FIGS. 10 and 11 illustrate an embodiment of a filter 120 that employs a differently configured second end plate 122 . The end plate 122 includes a first seal 124 that is configured for radial sealing with an outlet tube 126 of the head. The end plate 122 also includes a second seal 128 formed by an axially projecting rib with an inner surface 130 , and an angled outer surface 132 . The seal 128 fits into a channel formed in the head between an inner rib 134 and an outer rib 136 . The angled outer surface 132 engages and seals against an angled surface on the outer rib 136 , while the inner surface 130 seals against a surface of the inner rib 134 .
[0059] In addition, the end plate 122 includes a perimeter edge 140 that is shaped as a circumferentially continuous rounded bead. The beaded edge 140 is configured to snap fit connect with a rounded end 142 of the shell. This snap fit connection would permit replacement of the filter cartridge at the end of its useful life. Instead of a snap fit connection, the end 142 and the perimeter edge 140 can be spin welded together. Spin welding of filter parts is known in the art.
[0060] FIG. 12 illustrates an embodiment of a filter 150 that employs a differently configured second end plate 152 . In this embodiment, the end plate 152 includes a first seal 154 that is configured for radial sealing with an outlet tube 156 of the head. The end plate 152 also includes a second seal 158 that engages and seals against a sealing surface 160 that is similar to the sealing surface 26 in FIG. 9A . In addition, the end plate 152 includes a perimeter edge 162 that includes a circumferentially continuous, radial groove 164 that is configured to snap fit connect with a rounded end 166 of the shell. This snap fit connection would permit replacement of the filter cartridge at the end of its useful life. Instead of a snap fit connection, the end 166 and the perimeter edge 162 can be spin welded together.
[0061] FIG. 13 illustrates another embodiment of a second end plate 180 with a second seal 182 that has a rounded edge 184 that engages and seals with a rounded sealing surface on the head. A first seal 186 is configured for radial sealing with an outlet tube of the head.
[0062] FIGS. 14 and 15 illustrate an embodiment of a filter 200 where the threads that connect the filter 200 to the head are formed on an attachment cap 202 disposed adjacent to the open end of the filter and that is rotatable relative to the shell. An upper end 204 of the shell is flared outwardly and defines a shelf 206 . The cap 202 includes a bottom end that engages the shelf 206 , and an upper end that is internally threaded 208 for engagement with exterior threads on the head.
[0063] The filter 200 also includes a second end plate 210 with a first seal 212 that is configured similar to the first seal 154 in FIG. 12 , and a second seal 214 at a perimeter edge 216 . The perimeter edge 216 defines a radial slot that receives the end of the shell, where the second seal 214 defines the upper side of the slot and which seals with a sealing surface on the head. This construction permits the end plate 210 to be snap fitted into the shell. Alternatively, the end of the shell and the end plate 210 can be spin welded together. Also, the attachment cap 202 is loosely fitted on the end of the filter 200 . This permits the filter to be removed from the attachment cap 202 to allow replacement of the filter 200 .
[0064] FIGS. 16 and 17 illustrate another embodiment of a filter 231 which is similar in many respects to the filter 100 in FIG. 9 . Therefore only differences from the filter 100 will be described in detail and features that are similar to features in the filter 100 will be designated with same reference numerals. As shown in FIG. 16 , the head 230 is configured similar to the head 102 shown in FIGS. 9 , 9 A and 9 B, including fluid inlet and fluid outlet, and a similar sealing surface 26 and outlet tube 91 .
[0065] The filter 231 primarily differs from the filter 100 with respect to the shell, which has no threads formed on it, and the connecting arrangement that connects the filter 231 to the filter head 230 . The filter 231 is connected to the head 230 in a similar manner to the filter 200 as shown in FIG. 14 , where the threads that connect the filter 231 to the head 230 are formed on an attachment cap 236 disposed adjacent to the open end of the filter shell 232 and that is rotatable relative to the shell. The cap 236 includes a bottom end 238 that engages a shelf 233 formed on the shell 232 and an upper end that is internally threaded 237 for engagement with exterior threads 239 on the head 230 .
[0066] The lower, non-illustrated portions of the filters in FIGS. 10-14 and 16 can be similar to the lower filter portions illustrated in FIGS. 1-2 and 9 , or they can have a different configuration than in FIGS. 1-2 and 9 .
[0067] With reference to FIGS. 18 and 19 , a filter 250 constructed in accordance with the concepts described herein is illustrated next to a prior art filter 300 that uses a nut plate. As described above, the filter 250 has two main subassemblies, namely a shell and a filter cartridge, where the filter cartridge comprises filter media, a center tube, a molded bottom endplate and a molded top endplate that is fixed at its perimeter edge to the shell to close the open end of the shell and which defines first and second seals. Avoiding the nut plate allows more space availability at the top of the filter, which can be used to increase the slit width of the filter media (shown in FIG. 5 ) resulting in increased filter media area, or used to reduce the axial length of the filter. In addition, since the molded top end plate extends to and closes the open end of the shell, the pleat depth of the filter media (shown in FIG. 5 ) can be increased, resulting in increased filter media area.
[0068] In contrast, the prior art filter 300 includes all of the components listed in FIG. 19 . In addition, the presence of the nut plate results in an increase in the axial length of the filter 300 compared to the axial length of the filter 250 .
[0069] The invention may be embodied in other forms without departing from the spirit or novel characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein. | A spin-on filter that eliminates the use of a nut plate and reduces the number of separate components. Instead, the spin-on filter utilizes the end plate of the filter cartridge to perform a number of functions, including closing the open end of the filter shell, sealing between the dirty and clean fluid sides, sealing between the filter and the mounting head to prevent leakage outside the filter to environment, attaching the filter cartridge to the shell, and sealing the end of the filter media. | 1 |
[0001] The present description is related to U.S. patent application Ser. No. 10/822,226 entitled DETECTING PUBLIC NETWORK ATTACKS USING SIGNATURES AND FAST CONTENT ANALYSIS, filed on Apr. 8, 2004, which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present disclosure generally relates to the field of network security and more particularly relates to the prevention of self-propagating worms and viruses through data traffic analysis.
[0004] 2. Related Art
[0005] Many computers are connected to publicly-accessible networks such as the Internet. This connection has made it possible to launch large-scale attacks of various kinds against computers connected to the Internet. A large-scale attack is an attack that involves several sources and destinations, and which often (but not necessarily) involves a large traffic footprint. Examples of such large-scale attacks may include: (a) viruses, in which a specified program is caused to run on the computer, which then attempts to spread itself to other computers known to the host computer (e.g., those listed in the address book); and (b) denial of service attacks (DoS), in which a group of computers is exposed to so many requests that it effectively loses the ability to respond to legitimate requests. Many viruses and worms indirectly cause DoS attacks as well for networks by sending a huge amount of traffic while replicating. Distributed denial of service (DDOS) occurs when an attacker uses a group of machines (sometimes known as zombies) to launch a DoS attack.
[0006] Another form of large-scale attack is called backdoor or vulnerability scanning. In such an attack an intruder scans for backdoors at machines or routers. A backdoor is a method by which a previously attacked machine can then be enlisted by future attackers to be part of future attacks.
[0007] Spam is unsolicited network messages often sent for commercial purposes. Large-scale spam is often simply the same as (or small variants of) the spam sent to multiple recipients. Note that this definition of spam includes both email as well as newer spam variants such as Spam Sent Over Instant Messenger.
[0008] A specific form of attack is an exploit, which is a technique for attacking a computer, which then causes the intruder to take control of the target computer, and run the intruder's code on the attack machine. A worm is a large-scale attack formed by an exploit along with propagation code. Worms can be highly efficacious, since they can allow the number of infected computers to increase geometrically. The worm can do some specific damage, or alternatively can simply take up network bandwidth and computation, or can harvest e-mail addresses or take any other desired action.
[0009] Many current worms propagate via random probing. In the context of the Internet, each of the number of different computers has an IP address, which is a 32-bit address. The probing can simply randomly probe different combinations of 32-bit addresses, looking for machines that are susceptible to the particular worm. Once the machine is infected, that machine starts running the worm code, and again begins probing the Internet. This geometrically progresses.
[0010] A very common exploit is a so-called buffer overflow. In computers, different areas of memory are used to store various pieces of information. One area in memory may be associated with storing information received from the network: such areas are often called buffers. However, an adjoining area in the memory may be associated with an entirely different function. For example, a document name used for accessing Internet content (e.g., a URL) may be stored into a URL buffer. However, this URL buffer may be directly adjacent to protected memory used for program access. In a buffer overflow exploit, the attacker sends a URL that is longer than the longest possible URL that can be stored in the receiver buffer and so overflows the URL buffer which allows the attacker to store the latter portion of its false URL into protected memory. By carefully crafting an extra long URL (or other message field), the attacker can overwrite the return address, and cause execution of specified code by pointing the return address to the newly installed code. This causes the computer to transfer control to what is now the attacker code, which executes the attacker code.
[0011] The above has described one specific exploit (and hence worm) exploiting the buffer overflow. A security patch that is intended for that exact exploit can counteract any worm of this type. However, the operating system code is so complicated that literally every time one security hole is plugged, another is noticed. Further, it often takes days for a patch to be sent by the vendor; worse, because many patches are unreliable and end users may be careless in not applying patches, it may be days, if not months, before a patch is applied. This allows a large window of vulnerability during which a large number of machines are susceptible to the corresponding exploit. Many worms have exploited this window of vulnerability.
[0012] A signature is a string of bits in a packet that characterize a specific attack. For example, an attempt to execute the perl program at an attacked machine is often signaled by the string “perl.exe” in a message/packet sent by the attacker. Thus a signature-based blocker could remove such traffic by looking for the string “perl.exe” anywhere in the content of a message. The signature could, in general, include header patterns as well as exact bit strings, as well as bit patterns (often called regular expressions) which allow more general matches than exact matches.
[0013] While the exact definition of the different terms above may be a matter of debate, the basic premise of these, and other attacks, is the sending of undesired information to a publicly accessible, computer, connected to a publicly accessible network, such as the internet.
[0014] Different ways are known to handle such attacks. One such technique involves using the signature, and looking for that signature in Internet traffic to block anything that matches that signature. A limitation of this technique has come from the way that such signatures are found. The signature is often not known until the first attacks are underway, at which point it is often too late to effectively stop the initial (sometimes called zero-day) attacks.
[0015] An Intrusion Detection System (IDS) may analyze network traffic patterns to attempt to detect attacks. Typically, IDS systems focus on known attack signatures. Such intrusion detection systems, for example, may be very effective against so-called script kiddies who download known scripts and attempt to use them over again, at some later time.
[0016] Existing solutions to attacks each have their own limitations. Hand patching is when security patches from the operating system vendor are manually installed. This is often too slow (takes days to be distributed). It also requires large amounts of resources, e.g., the person who must install the patches.
[0017] A firewall may be positioned at the entrance to a network, and reviews the packets coming from the public portion of the network. Some firewalls only look at the packet headers; for example, a firewall can route e-mail that is directed to port 25 to a corporate e-mail gateway. The firewalls may be useful, but are less helpful against disguised packets, e.g., those disguised by being sent to other well-known services.
[0018] Intrusion detection and prevention systems, and signature based intrusion systems look for an intrusion in the network. These are often too slow (because of the time required for humans to generate a signature) to be of use in a rapidly spreading, new attack.
[0019] Other systems can look for other suspicious behavior, but may not have sufficient context to realize that certain behavior accompanying a new attack is actually suspicious. For example, a common technique is to look for scanning behavior but this is ineffective against worms and viruses that do not scan. This leads to so-called false negatives where more sophisticated attacks (increasingly common) are missed.
[0020] Scanning makes use of the realization that an enterprise network may be assigned a range of IP addresses, and may only use a relatively small portion of this range for the workstations and routers in the network. Any outside attempts to connect to stations within the unused range may be assumed to be suspicious. When multiple attempts are made to access stations within this address space, they may increase the level of suspicion and make it more likely that a scan is taking place. This technique has been classically used as part of the so-called network telescope approach.
SUMMARY
[0021] A content sifting system and method is provided that automatically generates a signature for a worm or virus. The signature can then be used to significantly reduce the propagation of the worm elsewhere in the network or eradicate the worm altogether. A complementary value sampling method and system is also provided that increases the throughput of network traffic that can be monitored. Together, the methods and systems identify invariant strings that appear in or across packets and track the number of times those invariant strings appear along with the network address dispersion of those packets that include the invariant strings. When an invariant string reaches a particular threshold of appearances and address dispersion, the string is reported as a signature for a suspected attack.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The details of the present invention, both as to its structure and operation, may be gleaned in part by study of the accompanying drawings, in which like reference numerals refer to like parts, and in which:
[0023] FIG. 1A is a network diagram illustrating an example network according to an embodiment of the invention;
[0024] FIG. 1B is a network diagram illustrating an example network according to an embodiment of the invention;
[0025] FIGS. 2A-C are block diagrams illustrating an example sensor unit according to an embodiment of the invention;
[0026] FIG. 3 is a block diagram illustrating an example packet according to an embodiment of the present invention;
[0027] FIG. 4 is a block diagram illustrating an example content prevalence table according to an embodiment of the invention;
[0028] FIG. 5 is a block diagram illustrating an example address dispersion table according to an embodiment of the invention;
[0029] FIG. 6 is a functional block diagram illustrating an example hashing technique according to an embodiment of the invention; and
[0030] FIG. 7 is a flow diagram illustrating an example process for identifying a worm signature according to an embodiment of the invention.
DETAILED DESCRIPTION
[0031] Certain embodiments as disclosed herein provide for systems and methods for identifying an invariant string or repeated content to serve as a signature for a network attack such as a worm or virus. For example, one method and system as disclosed herein allows for a firewall or other sensor unit to examine packets and optimally filter those packets so that invariant strings within or across packets are identified and tracked. When the frequency of occurrence of a particular invariant string reaches a predetermined threshold and the number of unique source addresses and unique destination addresses also reach a predetermined threshold, the particular invariant string is reported as a signature for a suspected worm. For ease of description, the example embodiments described below refer to worms and viruses. However, the described systems and methods also apply to other network attacks and the invention is not limited to worms and viruses.
[0032] After reading this description it will become apparent to one skilled in the art how to implement the invention in various alternative embodiments and alternative applications. However, although various embodiments of the present invention will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation. As such, this detailed description of various alternative embodiments should not be construed to limit the scope or breadth of the present invention as set forth in the appended claims.
[0033] FIG. 1A is a network diagram illustrating an example network 30 according to an embodiment of the invention. In the illustrated embodiment, a computer 10 , sensor unit 20 , and an aggregator unit 40 are part of and are communicatively coupled via the network 30 . The network 30 may be a local network, a wide area network, a private network, a public network, a wired network or wireless network, or any combination of the above, such as the ubiquitous Internet.
[0034] Internet messages are sent in packets including headers that identify the destination and/or function of the message. An IP header identifies both source and destination for the payload. A TCP header may also identify destination and source port number. The port number identifies the service which is requested from the TCP destination in one direction, and from the source in the reverse direction. For example, port 25 may be the port number used commonly for e-mail; port number 80 is often used for FTP and the like. The port number thus identifies the specific resources which are requested.
[0035] An intrusion is an attempt by an intruder to investigate or use resources within the network 30 based on messages over the network. A number of different systems are in place to detect and thwart such attacks. It has been recognized that commonalities between the different kinds of large-scale attacks, each of which attack a different security hole, but each of which have something in common.
[0036] Typical recent attacks have large numbers of attackers. Typical recent attacks often increase geometrically, but in any case the number of infected machines increases. Attacks may also be polymorphic, that is they change their content during each infection in order to thwart signature based methods.
[0037] The present systems and methods describe detecting patterns in data and using those patterns to determine the properties of a new attack. Effectively, this can detect an attack in the abstract, without actually knowing anything about the details of the attack. The detection of attack can be used to generate a signature, allowing automatic detection of the attack. Another aspect describes certain current properties which are detected, to detect the attack.
[0038] A technique is disclosed which identifies characteristics of an abstract attack. This technique includes looking for properties in network data which make it likely that an attack of a new or previous type is underway.
[0039] The present disclosure describes a number of different properties being viewed, however it should be understood that these properties could be viewed in any order, and other properties could alternatively be viewed, and that the present disclosure only describes a number of embodiments of different ways of finding an attack under way.
[0040] An aspect of the disclosed technique involves looking through large amounts of data that is received by the sensor 20 as shown in FIG. 1A . One embodiment discloses a truly brute force method of looking through this data; and this brute force method could be usable if large amounts of resources such as memory and the like are available. Another embodiment describes scalable data reduction techniques, in which patterns in the data are determined with reduced resources, e.g., smaller configurations of memory and processing.
[0041] The computer 10 may be any of a variety of types of computing devices such as a general purpose computer device. The computer 10 may be a user device or a server machine or any other type of computer device that performs a multi-purpose or dedicated service.
[0042] The sensor 20 is configured with a data storage area 22 . The sensor 20 may be any of a variety of types of computing devices such as a general purpose computer device. The sensor 20 may be a stand alone unit or it may be integral with the computer 10 or the aggregator 40 . There can be a single sensor 20 as shown or in other embodiments there can be a plurality of sensors that alone or collectively carry out the functions or a portion of the functions of the invention. The sensor 20 receives packets from the network 30 and analyzes the packets for indications of an attack. If a possible attack is detected, the sensor 20 can notify the aggregator 40 , which can then take appropriate action.
[0043] Similarly, the aggregator 40 is configured with a data storage area 42 and may be any of a variety of types of computing devices such as the general purpose computer device. Additionally, there may be one or more aggregators 40 that alone or collectively carry out the functions or a portion of the functions of the invention.
[0044] FIG. 1B is a network diagram illustrating an alternative example network 60 according to an embodiment of the invention. In the illustrated embodiment, the computer 10 is communicatively coupled with an intrusion system 70 and a firewall 80 via the network 60 . The computer 10 is also in communication with the Internet 90 via the firewall 80 or optionally through the intrusion system 70 .
[0045] The intrusion system 70 is configured with a data storage area (not shown) and may be in communication with the firewall 80 via the network 60 or optionally through a direct communication link 75 . The intrusion system 70 is also in communication with the Internet 90 through the firewall 80 or optionally directly through communication link 95 . The intrusion system 70 preferably carries out the same function as the previously described sensor 20 and may be a stand alone unit or integrated with another device. In one embodiment, the intrusion system 70 can perform the combined functions of the previously described sensor 20 and the aggregator 40 .
[0046] The intrusion system 70 may be any of a variety of types of computing devices such as a general purpose computer device. There may be a single intrusion system 70 as shown or there may be more than one that alone or collectively carry out the functions or a portion of the functions of the invention. In an embodiment, the intrusion system 70 may be integrated with the firewall 80 into a combined device 85 . In such a case, the communication link 75 may take the form of shared memory or inter-process communication, as will be understood by one having skill in the art.
[0047] The firewall 80 is also configured with a data storage area (not shown) and may be any of a variety of types of computing devices such as a general purpose computer. Additionally, there may be one or more firewalls that alone or collectively carry out the functions or a portion of the functions of the invention described herein.
[0048] FIG. 2A is a functional block diagram illustrating an example sensor 20 according to an embodiment of the invention. In the illustrated embodiment, the sensor 20 is configured with a data storage area 22 and includes a communication module 100 , a destination checker module 110 , a content analysis module 120 , and a signature module 130 . The data storage area 22 may include both internal and external data storage and include volatile and non-volatile memory devices. The configuration of computing devices with various types of memory is well known in the art and will therefore not be discussed in detail herein.
[0049] The communication module 100 handles network communications for the sensor 20 and receives and processes packets appearing on the network interface (not shown). The communication module 100 may also handle communications with other sensors and one or more aggregators or computers. In one embodiment, when packets are received by the communication module 100 , they are provided to the destination checker module 110 , content analysis module 120 , and signature module 130 for further processing in parallel.
[0050] The destination checker module 110 examines packets based on a special assumption that there is known vulnerability in a destination machine. This makes the problem of detection much easier and faster. The destination checker module 110 analyzes the packets for known vulnerabilities such as buffer overflows at a specific destination port. For example, a list of destinations that are susceptible to known vulnerabilities is first consulted to check whether the destination of the current packet being analyzed is on the list. Such a list can be built by a scan of the network prior to the arrival of any packets containing an attack and/or can be maintained as part of routine network maintenance.) If the specific destination is susceptible to a known vulnerability, then the packet intended for that destination is parsed to determine if the packet data conforms to the vulnerability. For example, in a buffer overflow vulnerability for a URL, the URL field is found and its length is checked to see if the field is over a pre-specified limit. If the packet is determined to conform to a known vulnerability, delivery of that packet can be stopped. Alternatively, the contents of the packet that exploit the vulnerability (for example, the contents of the field that would cause a buffer overflow) are forwarded as an anomalous signature, together with the destination and source of the packet. The contents may be forwarded, for example, to an aggregator 40 as previously described with respect to FIG. 1A so that a possible attack may be identified and stopped.
[0051] Content analysis module 120 examines the content of a packet to determine if it meets criteria that are not necessarily based on a known vulnerability. For example, the content analysis module 120 may examine packets in the aggregate to determine if they contain repetitive content. It has been found that large attacks against network resources typically include content that repeats an unusual number of times. For example, the content could be TCP or IP control messages for denial of service attacks. By contrast, worms and viruses have content that contains the code that forms the basis of the attack, and hence that code is often repeated as the attack propagates from computer to computer. Spam has repeated content that contains the information the spammer wishes to send to a large number of recipients.
[0052] Advantageously, only the frequently repeated content (signatures) are likely to be problems. For example, a signature that repeats just once could not represent a large-scale attack. At most, it represents an attack against a single machine. Therefore, the frequent signatures may be further analyzed by the content analysis module 120 to determine if it is truly a threat, or is merely part of a more benign message.
[0053] The signature module 130 analyzes packet data to determine what signatures, if any, are included in the data payload. The signature module 130 may examine individual packets to find signatures or it may examine the data within a single packet and across packets to find signatures that extend across packet boundaries. The signature module 130 may work in concert with the other modules in the sensor 20 to provide them with information about signatures in packets.
[0054] FIG. 2B is a functional block diagram illustrating an example content analysis module 120 according to an embodiment of the invention. In the illustrated embodiment, the content analysis module 120 is configured with a data storage area 22 and includes a spreading module 122 , a correlation module 124 , an executable code detection module 126 , and a scanning module 128 .
[0055] The spreading module 122 is configured to determine whether a large (where “large” is defined by thresholds that can be set to any desired level) number of attackers or attacked machines are involved in sending/receiving the same content. The content is “common,” in the sense that the same frequent signatures are being sent. During a large-scale attack, the number of sources or destinations associated with the content may grow geometrically. This is in particular true for worms and viruses. For spam, the number of destinations to which the spam content is sent may be relatively large; at least for large-scale spam. For denial of service attacks, the number of sources may be relatively large. Therefore, spreading content may be an additional factor representing an ongoing attack.
[0056] When a frequent signature is detected, the spreading module 122 investigates whether the content is exhibits characteristics of spreading. This can be done, for example, by looking for and counting the number of sources and destinations associated with the content.
[0057] In a brute force example, a table of all unique sources and all unique destinations is maintained. Each piece of content is investigated to determine its source and its destination. For each string S, a table of sources and a table of destinations are maintained. Each unique source or destination may increment respective counters. These counters maintain a count of the number of unique sources and unique destinations.
[0058] When the same string S comes from the same source, the counter is not incremented. When that same string does come from a new source, the new source is added as an additional source and the unique source counter is incremented. The destinations are counted in an analogous way. The source table is used to prevent over-counting the number of sources. That is, if Sally continually sends the message “hi Joe” Sally does not get counted twice.
[0059] The frequent and spreading signatures found by the spreading module 122 can also be subjected to additional checks such as a check for executable code, spam, backdoors, scanning, and correlation. Each of these checks, and/or additional checks, can be carried out by modules, either software based, hardware based, or any combination thereof.
[0060] The correlation module 124 examines the source and destination of multiple packets to determine if an interval pattern is present. For example, a piece of content may be sent to a set of destinations in a first measured interval. In a later second measured interval, the same piece of content is sent by some fraction of these destinations acting as sources of the content. Such correlation can imply causality wherein infections sent to destinations in the first interval are followed by these stations acting as infecting agents in the later interval.
[0061] In one embodiment, a correlation test can be used to scalably detect the correlation between content sent to stations in one interval, and content sent by these sources in the next interval. The correlation test is a likely sign of an infection. Meeting the correlation test adds to the guilt score assigned to a piece of content.
[0062] For example, a bitmap for source addresses and a bitmap for destination addresses are initialized to “0” whenever a new signature is detected and added to what may be referred to as a frequent content table. A similar initialization occurs at the end of every time interval to reset the frequency. The concepts used are very similar to those described herein for detecting spreading content when similar bitmap structures can be used.
[0063] Thus, when a new signature is detected, the source IP address is hashed into the source bitmap and the destination IP address is analogously hashed into the destination bitmap. The bit positions set in the source bitmap for this interval are then compared with the bit positions set in the destination bitmap for the previous interval. If a large number of set bits are in common, it indicates that a large number of the destinations that received the content in the last interval are sending the same content in this interval. Accordingly, the correlation module 124 would identify that content as passing the correlation test.
[0064] Another example correlation test is a spam test conventionally known as the Bayesian spam test. The Bayesian test may heuristically analyze the content to determine if the suspected content is in fact spam according to the Bayesian rules.
[0065] The executable code detection module 126 detects the presence of executable code segments. The presence of executable code segments may also be an additional (but not necessary) sign of an attack. Worms and certain other attacks are often characterized by the presence of code (for example, code that can directly execute on Windows machines) in the attack packets they send. Therefore, in analyzing content to determine an infestation, the repeatable content is tested against parameters that determine executable code segments. It is unlikely that reasonably large segments of contiguous packet data will accidentally look like executable code; this observation is the basis of special techniques for determining the presence of code. In one aspect, a check is made for Intel 8086 and Unicode executable code formats.
[0066] In one embodiment, the executable code detection module 126 is configured to test each suspicious data segment that is identified. For example, a data segment starting at the beginning of a packet, at an offset, or spanning across packets can be tested for executable code. When code is detected to be over a specified length, the executable code detection module 126 reports a positive code test, for example to the sensor or intrusion system.
[0067] A variety of different code tests can be employed by the executable code detection module 126 . For example, a particular code test can simply be a disassembler nm on the packet at each of the plurality of offsets. Most worms and the like use 8086 code segments. Therefore, an 8086 disassembler can be used for this purpose.
[0068] Alternatively, a technique of looking for opcodes and associated information can be used as a code test. The opcodes may be quite dense, leaving only a few codes that are clearly not 8086 codes. Each opcode may have associated special information following the code itself. While a small amount of data may look like code, because of the denseness of the opcodes, it is quite unlikely that large strings of random data look like codes. For example, if 90% of the opcodes are assigned, a random byte of data has a 90% chance of being mistaken for a valid opcode; however, this is unlikely to keep happening when measured over 40 bytes of data that each of the appropriate bytes looks like a valid opcode.
[0069] This test, therefore, maintains a small table of all opcodes, and for each valid opcode the test uses the length of the instruction to test whether the bits are valid. In one example, the code test may start at offset O, perform a length test, and then repeat until a length greater than N for opcodes tests of length N. Then each bit at offset O along with its length in the opcode table, is looked up. If the opcode table indicates that the byte is invalid, the code test would fail. If the opcode table entry is valid, the length test is incremented by the opcode table entry length and the code test would continue. The system thus checks for code at offset O by consulting the table looking for a first opcode at O. If the opcode is invalid, then the test fails, and the pointer moves to test the next offset. However, if the opcode is valid, then the test skips the number of bytes indicated by the instruction length, to find the next opcode, and the test repeats. If the test has not failed after reaching N bytes from the offset O, then the code test has succeeded.
[0070] This test can be carried out on each string, using 8086 and unicode, since most of the attacks have been written in these formats. It should be understood, however, that this may be extended to other code sets where desirable to do so.
[0071] As previously described, the code test can be combined with the frequent content test or other tests to confirm whether a piece of frequent content contains at least one fragment of code. In an alternative embodiment, the code detection test can be used as a threshold test prior to the other tests such as the frequent content test. In such an embodiment, only content that has a code segment of size N or more would be considered for frequent content testing.
[0072] The scanning module 128 is configured to determine whether IP addresses or ports are being probed for potential vulnerability. For example, it may be necessary for an attacker to communicate with vulnerable sources in order to launch an attack. Scanning may be used by the attacker or worm/virus to find valid IP addresses to probe for vulnerable services. Probing of unused addresses and/or ports can be used by the attacker to make this determination. However it is possible that future attacks may also modify their propagation strategies to use pre-generated addresses instead of probing. Accordingly, one embodiment uses scanning only as an additional sign of an attack which is not necessary to output an anomalous signature.
[0073] In one embodiment, a scanning test is employed that, unlike conventional scanning systems, uses both the content and the source as keys for the test. Conventional systems tested only the source address. In the scanning test, tests are made for content that is being sent to unused addresses (of sources that disburse such content and send to unused addresses) and not solely sources. A guilt score is assigned to pieces of “bad” content, though as a side-effect, the individual stations disbursing the bad content may also be tagged. Notice also that the exploit in a TCP-based worm will not be sent to these addresses because a connection cannot be initiated without an answer from the victim.
[0074] In one embodiment, the scanning module 128 looks for a range of probes to an unused space. For example, a source address may make several attempts to communicate with an inactive address or port by mistake. A hundred attempts to a single unused address or port is less suspicious than a single attempt to each of a hundred unused addresses/ports. Thus rather than counting just the number of attempts to unused addresses, the scanning module 128 may also make an estimate of the range of unused addresses that have been probed.
[0075] To implement these augmentations scalably, a representation of the set of the unused addresses/ports of an enterprise or campus network is maintained by the scanning module 128 . For scalability, unused addresses can be done compactly using a bitmap (for example, for a Class B network, 64K bits suffices) or a Bloom Filter (described in Fan, et al., Summary Cache: A Scalable Wide-Area Web Cache Sharing Protocol, SIGCOMM 98, 1998). The list can be dynamically validated. Initial guesses about which address spaces are being used can be supplied by a manager. This can easily be dynamically corrected. For example, whenever an address S thought to be unassigned sends a packet from the inside, that address should be updated to be an assigned address. Note that in the special case of a contiguous address space, a simple network mask suffices.
[0076] A scalable list of unused ports can be kept by keeping an array with one counter for each port, where each array entry is a counter. The counter is incremented for every TCP SYN sent or each RESET sent, and decremented for every TCP FIN or FIN-ACK sent. Thus, if a TCP-based attack occurs to a port and many of the machines it contacts are not using this port, TCP FINs will not be sent back by these machines, or they will send TCP resets. Thus, the counter for that port will increase. Some care must be taken in implementing this technique to handle spoofing and asymmetrical routing, but even the simplest instance of this method will work well for most organizations.
[0077] A “blacklist” of sources that have sent packets to the unused addresses or ports in the last k measurement periods. This can be done compactly via a Bloom Filter or a bitmap. A hashed bit map can also be maintained, (similar to counting sources above) of the inactive destinations probed, and the ports for which scanning activity is indicated.
[0078] For each piece of frequent content, the mechanism keeps track of the range of sources in the blacklisted list associated with the content. Once again, this can be done scalably using a hashed bitmap as described herein. In one embodiment, testing for content of scanning can be implemented by hashing the source address of a suspicious signature S into a position within the bit map. When the number of bits set within that suspicion bit map exceeds a threshold, then the scanning is reported as true.
[0079] Note that while worms may evince themselves by the presence of reasonably large code fragments, other attacks such as Distributed Denial of Service may be based on other characteristics such as large amounts of repetition, large number of sources, and the reception of an unusually large number of TCP reset messages. The content analysis module 120 may identify spam, for example, as being characterized by repetitive presence of keywords identified based on heuristic criteria. These additional checks for spreading, correlation, executable code, scanning, and spam can be optional such that one or more or none of these tests may be used.
[0080] FIG. 2C is a functional block diagram illustrating an example signature module 130 according to an embodiment of the invention. In the illustrated embodiment, the signature module 130 is configured with a data storage area 22 and includes a parser module 132 , a filter module 134 , a key module 136 , and a data module 138 . The signature module 130 is configured to examine packets for signatures that appear within a single packet or are spread across packets. The signature module 130 preferably works in connection with the other modules of the sensor 20 to detect a possible attack.
[0081] In an embodiment, the signature module 130 can perform a brute force examination of each packet that is received. It should be understood, however, that the brute force method of analyzing content could require incredible amounts of data storage. For example, commonly used intrusion systems/sensors that operate at 1 Gigabit per second, easily produce terabytes of packet content over a period of a few hours. Accordingly, a general data reduction technique may be used. It should be understood, however, that other detection techniques may be used without a general data reduction technique. Thus, in an embodiment, a data reduction technique can advantageously be used as part of those detection techniques that generate large amounts of data, such as signatures and source/destination addresses and ports.
[0082] In one aspect, a signature for a possible attack (also referred to as an “anomalous signature”) may be established when any frequent content is found that also meets an additional test such as spreading, correlation, executable code segments, or any other test. According to another aspect, the signatures may be scored based on the amount of indicia they include. In any case, this information is used to form anomalous signatures that may then be used to block operations or may be sent to a bank of signature blockers and managers such as the aggregator 40 previously described with respect to FIG. 1A .
[0083] In addition to the signature, if a packet signature is deemed to be anomalous according to the tests above, the destination and source of the packet may be stored. This can be useful, for example, to track which machines in a network have been attacked, and which ones have been infected.
[0084] An intrusion detection system (or sensor) device may also (in addition to passing the signature, source, destination, or other information) take control actions by itself. Standard control actions that are well known in the state of the art include connection termination (where the TCP connection containing the suspicious signature is terminated), connection rate limiting (where the TCP connection is not terminated but slowed down to reduce the speed of the attack), and packet dropping (where any packet containing the suspicious content is dropped with a certain probability). Note that when an attack is based on a known vulnerability, packet dropping with probability 1 can potentially completely prevent an attack from coming into a network or organization.
[0085] The signature module 130 is configured to identify a signature S from within any subset of the packet data payload and/or header. In general, a signature can be any subset of the data payload. A signature can also be formed from any portion of the data payload added to or appended to information from the packet header, for example, the TCP destination (or source) port. This type of signature recognizes that many attacks target specific destination (or in some limited cases, source) ports. An offset signature is based on the recognition that modern large-scale attacks may become polymorphic—that is, may modify the content on individual attack attempts. This is done to make each attack attempt look like a different piece of content. Complete content change is unlikely, however. Some viruses add small changes, while others encrypt the virus but add a decryption routine to the virus. Each contains some common piece of content; in the encryption example, the decryption routine would be the common piece of content.
[0086] The attack content may lie buried within the packet content and may be repeated, but other packet headers may change from attack to attack. Thus, according to another embodiment, the signature is formed by any continuous portion in the data payload, appended to the TCP destination port. Therefore, the signature module 130 investigates for content repetition strings anywhere within the TCP payload. For example, the text “hi Joe” may occur within packet 1 at offset 100 in a first message, and the same text “hi Joe” may occur in packet 2 at offset 200 . This signature module 130 allows for counting these as two occurrences of the same string despite the different offsets in each instance.
[0087] The evaluation of this occurrence is carried out by evaluating all possible substrings in the packet of any certain length. A value of a substring length can be chosen, for example, 40 bytes. Then, a data payload each piece of data coming in may be windowed, to first look for bytes 1 through 40 , then look for bytes 2 through 41 , then look for bytes 3 through 42 . All possible offsets are evaluated.
[0088] Determining the length of substrings that are evaluated is a trade-off depending on the desired amount of processing. Longer substrings will typically have fewer false positives, since it is unlikely that randomly selected substrings can create repetitions of a larger size. On the other hand, shorter substrings may make it more difficult for an intruder to evade attacks.
[0089] Certain attacks may chop the attack into portions which are separated by random filler. However, these separated portions will still be found as several invariant content substrings within the same packet. In such an attack, a multi-signature may be identified by the signature module 130 . A multi-signature may comprise one or more continuous portions of payload combined with information from the packet header such as the destination port.
[0090] Other attacks may break the attack into portions that are separated across two or more packets. In such an attack, when the packets are received and placed in order, the data payloads can be examined such that predetermined sized strings that span adjacent packets are analyzed for invariant content substrings that cross packet boundaries. Thus, an inter-packet signature may be identified that comprises a portion of payload from a first packet with a portion of payload from a second packet. Furthermore, the two source packets for the inter-packet signature are preferably adjacent when reordered.
[0091] The parser module 132 receives packets and parses the header and data payload from the packet. The parser module 1320 additionally extracts information from the packet header such as the protocol, the source IP address, the destination IP address, the source IP (or UDP) port, and the destination IP (or UDP) port just to name a few. The parser module 132 also breaks down the data payload into predetermined sized strings for further processing by other components of the sensor. As described, the predetermined sized strings may extend across packet boundaries such that a single predetermined sized string may have a portion of its content from a first packet and a portion of its content from a second, adjacent packet.
[0092] The filter module 134 may be implemented in hardware as a series of parallel processors or application specific integrated circuits. Alternatively the filter module 134 may be implemented in software that includes one or more routines. Advantageously, the software may be threaded so that the filtering process implemented in software is also a parallel process to the extent allowed by the associated hardware on which the software is running. The function of the filter 134 is to optimally reduce the number of predetermined sized strings that are processed while maintaining high efficacy for virus detection, as described later in detail with respect to FIG. 6 .
[0093] The key manager 136 identifies the invariant strings from the data payload that may qualify as a signature, for example, due to their repetitive nature, inclusion of code segments, matching a predetermined string, etc. The key manager 136 may combine information from the packet header with an identified string of content from the packet data payload to create a key. Each key is possibly a worm or virus signature. Alternatively, the key manager 136 may create a key from the string of content alone or from the string of content in combination with other information selected from the packet header such as the destination IP address or the destination port. In an embodiment, the key manager 136 performs data reduction on the key to minimize the size of the key.
[0094] In one embodiment, a data reduction technique called hashing may be employed. Hashing is a set of techniques to convert a long string or number into a smaller number. A simple hashing technique is often to simply remove all but the last three digits of a large number. Since the last three digits of the number are effectively random, it is an easy way to characterize something that is referred by a long number. For example, U.S. Pat. No. 6,398,311 can be described simply the 311 patent. However, much more complex and sophisticated forms of hashing are known.
[0095] In one example, assume the number 158711, and that this number must be assigned to one of 10 different hashed “bins” by hashing the number to one of 10 bins. One hashing technique simply adds the digits 1+5+8+7+1+1 equals 23. The number 23 is still bigger than the desired number of 10. Therefore, another reduction technique is carried out by dividing the final number by 10, and taking the remainder (“modulo 10”). The remainder of 23 divided by 10 is 3. Therefore, in 158711 is assigned to bin 3 . In this technique, the specific hash function is: (1) add all the digits; and (2) take the remainder when divided by 10.
[0096] The same hash function can be used to convert any string into a number between 0 and 9. Different numbers can be used to find different hashes.
[0097] The hash function is repeatable, that is, any time the hash function receives the number 158711, it will always hash to bin 3 . However, other numbers will also hash to bin 3 . Any undesired string in the same bin as a desired string is called a hash collision.
[0098] Many other hash functions are known, and can be used. These include Cyclic Redundancy Checks (CRCs) commonly used for detecting errors in packet data in networks, a hash function based on computing multiples of the data after division by a pre-specified modulus, the so-called Carter-Wegman universal hash functions (the simplest instantiation of which is to multiply the bit string by a suitably chosen matrix of bits), hash functions such as Rabin hash functions based on polynomial evaluation, and one-way hash functions such as MD-5 used in security. This list is not exhaustive and it will be understood that other hash functions and other data reduction techniques can be used.
[0099] A data reduction technique that is advantageous to use with the data payload subsections 230 described with respect to FIG. 3 allows adding a part of the hash and removing a part when moving between two adjacent subsections. One aspect of this embodiment, therefore, may use an incremental hash function. Incremental hash functions make it easy to compute the hash of the next substring based on the hash of the previous substring. One classic incremental hash function is a Rabin hash function (used previously by Manber in spotting similarities in files instead of other non-incremental hashes (e.g, SHA, MD5, CRC32)).
[0100] A large data payload may contain thousands of bytes. Accordingly, to minimize the probability of hash collisions (where different source strings result in the same value after hashing) the data reduction may be, for example, a hash to 64 bits.
[0101] The string S that is hashed may also include information about the destination port. The destination port generally remains the same for a worm, and may distinguish frequent email content from frequent Web content or peer-to-peer traffic in which the destination port changes.
[0102] In an embodiment, use of the Rabin hash function (also called the Rabin fingerprint) advantageously simplifies the analysis of data across packets. In an embodiment, the last 40 byte subsection of the data payload of a packet is stored after the packet processing is complete. The Rabin fingerprint for that subsection is also stored. When the next data payload is analyzed, the Rabin fingerprint is computed for the 40 byte subsection that includes the last 39 bytes of the previous packet and the first byte from the new packet. In this fashion, the packets may be examined and analyzed as a continuous stream of data—across packet boundaries. This allows the detection of an attack that spreads invariant strings across packets.
[0103] After a signature or key is created, the data manager 138 processes the signature. In an embodiment, the signature is subjected to a frequent signature test. Each key can be stored in a database. For example, the data manager 138 may maintain a content prevalence table and an address dispersion table (described later with respect to FIGS. 4 and 5 , respectively). The content prevalence table includes entries for keys and the number of times the particular key has been encountered (“count”). If a newly generated key is not present in the address dispersion table, the key is placed in the content prevalence table for tracking of the number of times the key is encountered. When the count for a particular key in the content prevalence table exceeds a predetermined threshold, the data manager 138 moves the key into the address dispersion table. In an embodiment, the content prevalence and address dispersion tables may be periodically flushed or specific entries may individually expire after a predetermined time period.
[0104] FIG. 3 is a block diagram illustrating an example packet 200 according to an embodiment of the present invention. In the illustrated embodiment, the packet 200 comprises a header 210 and a data payload 220 . The header 210 typically includes information relevant to the packet 200 such as the protocol by which the packet should be processed, the source IP address, the source IP port, the destination IP address, and the destination IP port. Other information may also be advantageously located in the header 210 .
[0105] The data payload 220 can be very large and is preferably divided up into smaller more manageable sized chunks, for example by the aforementioned parser. These more manageable sized chunks are shown as payload subsections 230 . The size of a payload subsection can vary and is preferably optimized based on the processing power of the sensor 20 , available memory 22 , and other performance or result oriented parameters. In one embodiment, the size of a payload subsection 230 is 40 bytes.
[0106] Alternatively, the data payload subsections can be all of the contiguous strings in the data payload of any length. Or the subsections may be all of the contiguous strings in the data payload with the same length. Other possible combinations of data payload subsections may also be employed as will be understood by those skilled in the art. In a preferred embodiment, each subsection is 40 bytes, with the first subsection comprising bytes 1 - 40 ; the second subsection comprising bytes 2 - 41 ; the third subsection comprising bytes 3 - 42 ; and so on until each byte in the data payload is included in at least one subsection.
[0107] FIG. 4 is a block diagram illustrating an example content prevalence table 250 according to an embodiment of the invention. In the illustrated embodiment, each row of the content prevalence table 250 includes a key and a count. For example, the count may represent the number of times the specific key has been encountered. As previously described, the key may be a string from the data payload of a packet and may also include the protocol and/or destination port information from the packet header. Alternatively, the key may be a representation of the string from the data payload (or the string combined with header information) after a data reduction has been performed.
[0108] In an embodiment, the data manager 138 (previously described with respect to FIG. 2C ) may maintain the content prevalence table 250 . For example, when an new key is identified, the key is looked up in the content prevalence table 250 . If the key is not in the table, it is added to the table along with a count of 0. Alternatively, if the key is already in the table, then the count associated with the key is incremented.
[0109] Additionally, a frequency threshold can also defined. Thus, if the count for a particular key exceeds the frequency threshold, then the key is identified as a frequent or repetitive key. In an alternative embodiment, a time threshold may also be defined for each entry in the content prevalence table 250 . Accordingly, when the time threshold is reached for a particular entry, the counter can be reset so that the frequent content test effectively requires the key to be identified a certain number of times during a specified time period.
[0110] FIG. 5 is a block diagram illustrating an example address dispersion table 270 according to an embodiment of the invention. In the illustrated embodiment, each row of the address dispersion table 270 includes a key and a count of the unique source IP addresses and a count of the unique destination IP addresses associated with the key. When a particular key in the content prevalence table 250 is identified as being a frequent or repetitive key, the data manager preferably creates an entry in the address dispersion table 270 for that key. Alternatively, when the key manager identifies a key that already exists in the address dispersion table 270 , the relative counts for the unique source IP address and the unique destination IP address is updated if necessary.
[0111] Because the tables illustrated in FIGS. 4 and 5 may become quite huge in practice, data reduction techniques may be performed to manage the content prevalence and the address dispersion tables. For example, a data reduction hash may be performed on one or both of the tables 250 and 270 .
[0112] In an embodiment, an optional front end test such as a Bloom Filter (described in Burton Bloom: Space/Time Tradeoffs In Hash Coding With Allowable Errors; Communications ACM, 1970) or a counting Bloom Filter (described in Fan, et al., Summary Cache: A Scalable Wide-Area Web Cache Sharing Protocol, SIGCOMM 98, 1998) to sieve out content that is repeated only a small number of times.
[0113] FIG. 6 is a functional block diagram illustrating an example hashing technique according to an embodiment of the invention. In general, for a more scalable storage of content in the content prevalence and/or address dispersion tables, a certain number k of hash stages are established. Each stage 1 hashes the value S using a specified hash function Hash(I), where Hash(I) is a different hash function for each stage 1 . For each of those stages, a specific position, k(I) is obtained from the hashing. The counter in position k(I) is incremented in each of the k stages. Then, the next I is established. Again, there are k stages, where k is often at least three, but could even be 1 or 2 in some instances.
[0114] The data reduction hashing system checks to see if all of the k stage counters that are incremented by the hash for a specific string S are greater than a stage frequency threshold. S is added to the frequent content table only when all of the k counters are all greater than the threshold.
[0115] Specifically with respect to FIG. 6 , when k=3, the data reduction technique would be called a 3 stage hash. Each stage is a table of counters which is indexed by the associated hash function (Hash(I)) that is computed based on the packet content. At the beginning of each measurement interval, all counters in each stage are initialized to 0. Each packet comes in (e.g., Packet S) and is hashed by a hash function associated with the stage. The result of the hash is used to set a counter in that stage.
[0116] For example, the packet S is hashed by a stage 1 hash function. This produces a result of 2, shown incrementing counter 2 in the stage 1 counter array. The same packet S is also hashed using the stage 2 hash function, which results in an increment to counter 0 in the stage 2 counter array. Similarly, the packet S is hashed by the stage 3 hash function, which increments counter 6 of the stage 3 counter array. In this example, the same packet hashes to three different sections (in general, though there is a small probability that these sections may coincide) in the three different counter stages.
[0117] After the hashing, the stage detector 290 determines if the counters that have currently been incremented are each above the frequency threshold. The signature is added to the frequent content memory 295 only when all of the stages have been incremented above the stage frequency threshold.
[0118] As examples, the stage 1 hash function could sum digits and take the remainder when divided by 13. The stage 2 hash function could sum digits and take the remainder when divided by 37 and the stage 3 hash function could be a third independent function. In an embodiment, parameterized hash functions may be used, with different parameters for the different stages, to produce different but independent instances of the hash function.
[0119] The use of multiple hash stages with independent hash functions reduces the problems caused by multiple hash collisions. Moreover, the system is entirely scalable. By simply adding another stage, the effect of hash collisions is geometrically reduced. Moreover, since the memory accesses can be performed in parallel, this can form a very efficient, multithreaded software or hardware implementation.
[0120] Advantageously, the bits in the individual stage counter arrays can be weighted by the probability of hash collisions, in order to get a more accurate count. When counting source and destination IP address, the weighting provides a more accurate count of the number of unique sources and destinations. Additionally, when applied to counting IP addresses, this technique effectively creates and stores a bitmap, where each bit represents an IP address. Advantageously, the storage requirements are significantly reduced, rather than storing the entire 32-bit IP address in an address table.
[0121] While the bitmap solution is better than storing complete addresses, it still may require keeping hundreds of thousands of bits per frequent content. Another solution carries out even further data compression by using a threshold T which defines a large value. For example, defining T as 100, this system only detects values that are large in terms of source addresses. Therefore, no table entries are necessary until more than 100 source addresses are found.
[0122] It also may be desirable to know not only the number of source addresses, but also the rate of increase of the source addresses. For example, it may be desirable to know that even though a trigger after 100 sources is made, that in the next second there are 200 sources, in the second after that there are 400 sources, and the like.
[0123] In an embodiment, even more scaling is achievable to advantageously use only a small portion of the entire bit map space. For example, if an identified signature is a frequent signature the IP address is hashed to a W bit number S HASH . Only certain bits of that hash are selected, e.g. the low order r bits. That is, this system scales down the count to only sampling a small portion of the bitmap space. However, the same scaling is used to estimate the complete bitmap space. The same scaling down operations are also carried out on the destination address.
[0124] For example, an array of 32-bits (i.e., r=32) may be maintained, where the threshold T is 96. Each source address of the content is hashed to a position between 1 and 96. If the position is between 1 and 32, then it is set. If the position is beyond 32, then it is ignored, since there is no portion in the array for that bit.
[0125] At the end of a time interval, the number of bits set into the 32-bit array is counted, and corrected for collisions. The value is scaled up based on the number of bits which were ignored. Thus, for any value of T, the number of bits set within the available portion of the registers is counted, and scaled by a factor of T. For example, in the previous example, if we had hashed from 1 to 96 but only stored 1 through 32, the final estimate would be scaled up by a factor of 3.
[0126] This technique may also be used to count a rising infection over several intervals, by changing the scaling factor. For example, a different scaling factor is stored along with the array in each interval. This technique can, therefore, reliably count from a very small to a very large number of source addresses with only a very small number of bits, and can also track rising infection levels.
[0127] Accordingly, the address is hashed and a scale factor for source addresses is assigned to a variable, e.g., SourceScale. If the high order bits of the hash from positions r+1 to r+SourceScale are all zero, the low order r bits are used to set the corresponding position in the source bit map. For example, if SourceScale is initially 3 and r is 32, essentially all but the low order 35 bits of the hash are ignored and the low order 32 bits of the 35 bits are focused on, a scaling of 2̂(35−32)=2̂3=8.
[0128] When the time interval ends, the counter is cleared, and the variable (SourceScale) is incremented by some amount. If, in the next interval the scale factor goes up to 4, the scaling focuses on the top 36 bits of the hash, giving a scaling of 2̂4=16. Thus by incrementing the variable (SourceScale) by 1, the amount of source addresses that can be counted is doubled. Thus when comparing against the threshold for source addresses, the number of bits in the hash is scaled by a factor of 2̂(SourceScale−1) before being compared to the threshold. This same technique can also be used for destination IP addresses.
[0129] FIG. 7 is a flow diagram illustrating an example process for identifying a worm signature according to an embodiment of the invention. At a high level, a network attack can be detected by receiving a plurality of packets on a network and analyzing the data payloads of those packets to detect common content among the packets. Data reduction techniques may also be employed to optimize the high level process. For example, initially, in step 300 , the sensor receives a packet. For example, the previously described communication module may receive the packet. Upon receipt, the packet is parsed in step 310 and header information is extracted and the data payload is divided up into a plurality of strings (subsections) as shown in step 320 . In an embodiment, the parsing function may be carried out by the previously described parser module. In a brute force method, the data payload may be divided up into the universe of all possible strings of one or more characters that are present in the data payload. Such an operation, however, is computationally expensive.
[0130] Alternatively, the data payload may be divided up into the universe of all strings having a minimum length. While this further reduces the number of strings relative to the minimum length, the operation remains computationally expensive.
[0131] In an embodiment, the data payload may be divided up into the universe of all strings of a specific length. This operation significantly reduces the number of strings created by the parsing of the data payload without compromise because each string created is representative of all longer strings including the baseline string. Advantageously, the specific string length can be optimized for detecting invariant strings in viruses and worms.
[0132] Additionally, if a specific length subsection is employed, then a portion of the data from the previous packet and a portion of the data from the current packet can be combined to create specific length subsections that span the packet boundary, as illustrated in step 330 . For example, if the specific length was 40 bytes, then the last 39 bytes of the data payload of the previous packet and the first byte from the data payload of the current packet can be combined to create a single subsection.
[0133] Once the data payload has been parsed into subsections, and combined with portions from an adjacent packet, the subsections are then filtered, as shown in step 340 .
[0134] In one embodiment, the filtering function may be carried out by the previously described filter module. The filtering may be carried out in a series of multi-stage hardware components or it may be carried out in software. The function of the filtering is to reduce the number of data payload subsections that require processing. In an embodiment, the Rabin fingerprint is calculated for each subsection and then only those subsections meeting a predetermined criteria are processed further. For example, after the Rabin fingerprint is calculated, each subsection that ends with six (6) zeroes is processed further. This may have the effect of thinning the number of subsections requiring processing to a fraction of the original number, for example to 1/64 th of the original number. Furthermore, because Rabin fingerprinting is randomly distributed, the creator of a worm or virus cannot know which subsections will be selected for further processing.
[0135] In one example, if the specific string length is 40 bytes and the thinning ratio is 1/64, the probability of tracking a worm with a signature of 100 bytes is 55%. However, the probability of tracking a worm with a signature of 200 bytes is 92% and the probability of tracking a worm with a signature of 400 bytes is 99.64%. Notably, all known worms today have had invariant content (i.e., a signature) of at least 400 bytes.
[0136] After the data payload subsections have been filtered, processing step 350 can be undertaken to determine if all of the subsections have been processed. If they have, then the process loops back to receive the next packet in step 330 . If all of the subsections have not been processed, then in step 360 a key is created for each data subsection. In one embodiment, the key creation may be carried out by the previously described key module. The key preferably includes the protocol identifier, the destination port, and the Rabin fingerprint for the data subsection. Alternatively, the key can include the Rabin fingerprint alone, or the Rabin fingerprint and the protocol, or the Rabin fingerprint and any combination of other identifying information. Once the key is created, the address dispersion table is consulted in step 370 to see if the key exists in the table. If the key does not exist in the address dispersion table, then the content prevalence table is updated in step 380 accordingly and the count for the key is initialized if the entry is new or incremented if the key was already present in the content prevalence table. If the count is incremented and the new count exceeds the predetermined threshold number as determined in step 390 , then an entry for the key is created in the address dispersion table as illustrated in step 400 . If the count does not exceed the threshold (or after the address dispersion table entry is created), the process returns to step 350 to determine if all subsections have been processed.
[0137] After an entry is created in the address dispersion table in step 400 , then the entry is updated to fill in the necessary information. Additionally, back in step 340 , if it is determined that an address dispersion table entry exists for the particular key, then the entry is updated. For example, the count for the source IP address and the count for the destination IP address can be updated in step 410 if those addresses are unique and have not yet been associated with the particular key.
[0138] After the address counts are updated, it is determined in step 420 if the new counts exceed a predetermined threshold. If they do, then in step 430 the key is reported (e.g., to the aggregator) as a possible signature for a suspected worm. Additionally, the packet (or packets if the data for the key came from two adjacent packets) containing the key are also reported. If the counts do not exceed the threshold (or after the report has been made), then the process returns to the step 350 to determine if all subsections have been processed.
[0139] Those of skill will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can often be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled persons can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the invention. In addition, the grouping of functions within a module, block, circuit or step is for ease of description. Specific functions or steps can be moved from one module, block or circuit without departing from the invention.
[0140] The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein can be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor can be a microprocessor, but in the alternative, the processor can be any processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
[0141] The steps of a method or technique described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium. An exemplary storage medium can be coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium can be integral to the processor. The processor and the storage medium can reside in an ASIC.
[0142] The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | Network worms or viruses are a growing threat to the security of public and private networks and the individual computers that make up those networks. A content sifting method if provided that automatically generates a precise signature for a worm or virus that can then be used to significantly reduce the propagation of the worm elsewhere in the network or eradicate the worm altogether. The content sifting method is complemented by a value sampling method that increases the throughput of network traffic that can be monitored. Together, the methods track the number of times invariant strings appear in packets and the network address dispersion of those packets including variant strings. When an invariant string reaches a particular threshold of appearances and address dispersion, the string is reported as a signature for suspected worm. | 7 |
[0001] The present application claims priority to DE 1 01 01 952.1, filed in Germany on Jan. 17, 2001, which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a method for the manufacture of chip board and fiber boards, or wood material boards to be pressed from long shavings.
BACKGROUND OF THE INVENTION
[0003] One such apparatus is disclosed in DE 43 33 61 4 A1. This apparatus consists of a spreading station, steam moistening apparatus, preheating section, and a continuously operating press, these four apparatuses being joined together in a continuously running and circulating manner by an endless woven metal belt having in each of its two marginal areas a heat-resistant plastic composition, for example Teflon.
[0004] The problem that was presented was that the press factor, especially in the processing of long shavings spread with orientation (resulting in OSB boards), is substantially greater than in the production of chip board. In addition to the negative influence of the coarse chip structure the poor press factor was due to the following: the processing of pressed boards of wood material, such as chip board, MDF (medium density fiber board), or OSB boards is performed technologically according to the principles that the wood particles—in this case the large-area oriented shavings for the OSB boards—are wetted with a moist fluid resin content (for example, phenolic resin binders), and that this water is evaporated when the chip mat in the press is heated, and the formation of steam, especially in the core of the boards being manufactured, produces a surrounding field of heat that is equal to or greater than 100° C. Since in the normal production of chip boards or MDF boards, the chip mat is enclosed between smooth press surfaces (hot plates or steel belts), a pressure higher than 1 bar can form between the large-area press zones. According to the steam pressure diagram, the temperature then rises with the rising steam pressure. In general, a temperature level of about 120° C. establishes itself between the upper and lower press surfaces. Due to the steam pressures in excess of 1 bar, an accelerated transfer of steam occurs from the outer layers to the middle layers, which results in an accelerated curing, especially in the core of the boards. This elevated steam pressure cannot establish itself through the metal mesh belt, because the mesh belt does not permit any build-up of pressure, so that only a wet steam is formed in the range around about 100° C., so that an accelerated curing in the core of the board is not possible. Ultimately, this results in the press factors that are approximately twice as high than in any normal production of chip boards.
[0005] For the reasons set forth, the production of OSB boards was economical only on a multiple-day apparatus with a very great number of stages. For the same reason, the use of continuously operating presses has hardly established itself in the production of OSB, because due to the high press factor, excessively long presses would have to be used, which would require an excessively high capital investment in proportion to productivity. On the other hand, however, the manufactured homes industry requires OSB boards in which at least one side displays a surface texture in the form of a mesh belt impression made by a metal wire mesh. The metal wire mesh serves in multi-stage presses for the transport of the coarse wood chips which are spread onto the metal wire mesh belt, and which cannot be pre-compressed in a fore-press. On the other hand, it provides for the surface texture on the pressed OSB boards which is functionally necessary for further processing.
[0006] With the method and apparatus according to DE 43 33 614 A1 it has been possible to improve the press factor to such an extent that an economical manufacture of chip boards can be achieved in a continuously operating press from a chip mat with large-area, oriented long shavings.
[0007] In the implementation of the invention according to DE 43 33 614 A1, it has developed that the method and the apparatus are suitable for the production of OSB in fast pressing time. The method and the apparatus, however, are capable of improvement, namely in regard to reducing the press time, the quality of the surface texture created, and the quality of the board.
[0008] An apparatus has furthermore been disclosed in DE 1 97 04 643 C2 in which, in the continuously operating press for the manufacture of primarily OSB boards, a circulating mesh belt is also carried through the press. In this apparatus the attempt has been made to prevent thermal expansions and differential expansions from resulting in damage to the steel belt and/or the mesh belt. The invention attempts to prevent damage by using a mesh belt and steel belt made of materials with equal thermal expansion properties, and by various measures to equalize their temperatures before they run into the continuously operating press. Thus relative movements between the steel belt and mesh belt are said to be prevented. But the steel belt and mesh belt have a very low thermal conductivity since they are made of high-alloy stainless steel. It has turned out that equipment of this kind has a production rating about 5% lower if the steel and metal mesh belts consist of high-alloy steels. The problem is that the heat has to be carried over the heating plates, through the steel belt and through the metal mesh belt to the surface of the material being pressed. The heat flow is hampered by the low thermal conductivity of the metal mesh belt. This reduced heat flow results in a slower heating of the material mat, especially in the center of the mat, within the continuously operating press, and thus results in longer press time and slower steel belt running and production rates.
SUMMARY OF THE INVENTION
[0009] The present invention is addressed to the problem of improving the quality of the texture of the manufactured boards of wood material, especially OSB boards, and achieving a longer life of the texturing metal mesh belt. The invention further makes it possible to adjust the process parameters for the wood material board between the textured side and the smooth side of the board to improve the production rate and product quality in regard to flexural strength and raw density profile, and to reliably assure the manufacture of a textured surface.
[0010] The present invention solves this and other problems. The present invention provides for a method for the continuous manufacture of wood material boards having a textured surface on at least one side, comprising: forming a mat of a wood or lignocellulose-containing material, treated with a binding agent, onto a continuously moving conveyor belt; introducing the mat between steel belts each circulating around one of an upper and lower frame part of a continuously operating press; and, after the step of introducing the mat, curing the mat in the continuously operating press to form one of a strand of boards and an endless wood material board by applying pressure and heat to the mat, wherein the continuously operating press comprises at least one endless metal mesh belt configured to circulate with a corresponding one of said steel belts and with the mat, wherein the metal mesh belt comprises a material having a thermal conductivity substantially higher than that of the corresponding steel belt and having a thermal expansion coefficient approximately equal to that of the corresponding steel belt, wherein the metal mesh belt and the corresponding steel belt are configured to pass through an insulating tunnel, in a return run, to reduce heat loss by thermal radiation, wherein the metal mesh belt is configured to pass through a heating tunnel, which is separated from the corresponding steel belt, wherein the heating tunnel is configured to heat the metal mesh belt to a temperature that is higher than a temperature of the corresponding steel belt by at least 40° C., and wherein curing the mat comprises applying a specific pressure to the mat of at least 0.3 N/mm 2 during a first at least 80% of a pressing time.
[0011] In one aspect of the present invention, the method further comprises the step of measuring a density profile of the formed one of the strand of boards and the endless wood material board, after the step of curing the mat, wherein the heating tunnel is configured to heat the metal mesh belt to a temperature profile that directly depends on said density profile.
[0012] In another aspect of the present invention, the method further comprises the step of adjusting a symmetrical or asymmetrical raw density profile in the formed one of the strand of boards and the endless wood material board, by adjusting a heat input into the side of the mat which is to be textured.
[0013] In another aspect of the present invention, the heating tunnel is configured to heat the metal mesh belt to a temperature that is higher than the temperature of the corresponding steel belt by at least 80° C.
[0014] In another aspect of the present invention, the step of introducing the mat comprises introducing the mat with a moisture content of less than or equal to approximately 9 weight-percent.
[0015] In another aspect of the present invention, the method further comprises the step of spraying one or both face strata of the mat with water.
[0016] In another aspect of the present invention, the method further comprises the step of preheating one or both face strata of the mat with steam.
[0017] The present invention also provides for a continuously operating press for the continuous manufacture of wood material boards having a textured surface on at least one side, comprising: an upper frame part and a lower frame part; two endless steel belts configured to draw a mat of material through the continuously operating press and to transfer press pressure, each steel belt associated with one of the upper frame part and the lower frame part; an endless metal mesh belt associated with a corresponding one of said steel belts; an insulating tunnel associated with said metal mesh belt and said corresponding steel belt; and a heating tunnel associated with said metal mesh belt and separated from said corresponding steel belt, wherein the metal mesh belt comprises a material having a thermal conductivity substantially higher than that of the corresponding steel belt and having a thermal expansion coefficient approximately equal to that of the corresponding steel belt, wherein the metal mesh belt and the corresponding steel belt are configured to pass through the insulating tunnel, in a return run, to reduce heat loss by thermal radiation, wherein the metal mesh belt is configured to pass through the heating tunnel, and wherein the heating tunnel is configured to heat the metal mesh belt to a temperature that is higher than a temperature of said corresponding steel belt by at least 40° C.
[0018] In one aspect of the present invention, the continuously operating press is configured to apply a specific pressure to the mat of at least 0.3 N/mm 2 during a first at least 80% of a pressing time.
[0019] The present invention also provides for an apparatus for the continuous manufacture of wood material boards having a textured surface on at least one side, comprising: a spreading station configured to spread an unoriented or oriented mixture of binding agent and one of chips and shavings to form a mat of material; a continuously operating press; and a conveyor belt configured to continuously move under the spreading station and configured to transfer the mat of material to the continuously operating press, wherein the continuously operating press comprises: an upper frame part and a lower frame part; a heatable and coolable press platen mounted on each of the upper frame part and the lower frame part; two endless steel belts configured to draw the mat of material through the continuously operating press and to transfer press pressure, each steel belt associated with one of the upper frame part and the lower frame part; driving and idler drums configured to support and carry said steel belts; an endless metal mesh belt associated with a corresponding one of said steel belts; an insulating tunnel associated with said metal mesh belt and said corresponding steel belt; and a heating tunnel associated with said metal mesh belt and separated from said corresponding steel belt, wherein the metal mesh belt comprises a material having a thermal conductivity substantially higher than that of the corresponding steel belt and having a thermal expansion coefficient approximately equal to that of the corresponding steel belt, wherein the metal mesh belt and the corresponding steel belt are configured to pass through the insulating tunnel, in a return run, to reduce heat loss by thermal radiation, wherein the metal mesh belt is configured to pass through the heating tunnel, wherein the heating tunnel is configured to heat the metal mesh belt to a temperature that is higher than a temperature of said corresponding steel belt by at least 40° C, and wherein the continuously operating press is configured to apply a specific pressure to the mat of at least 0.3 N/mm 2 during a first at least 80% of a pressing time.
[0020] In another aspect of the present invention, the heating tunnel comprises exactly one or two heating plates, or exactly one heating roll.
[0021] In another aspect of the present invention the metal mesh belt comprises a warp and filling, and wherein the warp and filling each consist of cast steel, or the warp consists of stainless steel and the filling consists of cast steel.
[0022] In another aspect of the present invention, the apparatus further comprises a cleaning brush with a blower tube and a vacuum cleaner, configured to continuously clean the metal mesh belt.
BRIEF DESCRIPTION OF THE DRAWING
[0023] The drawing shows a schematic view of a preferred embodiment of the present invention.
DETAILED DESCRIPTION
[0024] Referring to the drawing, the mat 10 of material to be pressed, composed of oriented or unoriented long shavings or chips, is spread onto a conveyor belt 13 at the spreading station 12 . The conveyor belt 13 serves to carry the mat 10 through a sprayer 23 and a preheating apparatus 22 into the continuously operating press 1 . The endless conveyor belt 13 is carried over guide pulleys 14 . The continuously operating press 1 can be a so-called double belt press, the main parts of which consist of a movable upper frame part 3 and a fixed bottom frame part 2 forming the adjustable press gap 11 . Upper frame part 3 and bottom frame part 2 are driven by driving drums 8 and idler drums 9 with steel belts 4 and 5 . On the sides of upper frame part 3 and bottom frame part 2 facing the press gap lithe heated and cooled press platens 6 and 7 are mounted. The finished wood material board exiting from the continuously operating press 1 is identified at 19 .
[0025] According to a preferred embodiment of the present invention, an accompanying metal mesh belt 15 is associated with at least one of the steel belts 4 or 5 (the upper steel belt 5 , as shown in the drawing). The metal mesh belt 15 comprises a material of greater thermal conductivity than the steel belt 4 or 5 . The steel belt 4 or 5 and the accompanying metal mesh belt 15 are returned together through an isolating tunnel 16 in order to prevent loss due to thermal radiation and to save energy. The metal mesh belt 15 is heated in a heating tunnel 18 , before it enters the press gap 11 , to a temperature higher than that of the corresponding steel belt 4 or 5 at the entrance to the press gap 11 . In the heating tunnel 18 the metal mesh belt 15 is carried over a lower heating plate 24 with which an upper heating plate 21 may also be associated. The preheating of the metal mesh belt 15 can also be performed by means of a heating roll 20 , in which case preferably the last guide pulley 17 ahead of the entrance to the press gap 11 is made to be a heating roll 20 . In another embodiment of the present invention, the metal mesh belt 15 may be constantly cleaned by a cleaning brush with an air blast bar and exhaust.
[0026] Of special importance is the choice of the material of the metal mesh belt, its higher thermal conductivity, the higher temperature of the metal mesh belt upon entry into the press gap, and the specific press pressure during the first 80% to 90% of the pressing time.
[0027] Table 1 shows the thermal conductivity of metal mesh belts of various materials. From this it is seen that the metal mesh belt of high-alloy stainless steel has a very low thermal conductivity. According to the invention, a belt is used as the metal mesh belt which has an at least 70% greater thermal conductivity than the steel belt. That is, a metal mesh belt of cast steel or preferably of a mixture of cast steel and stainless steel is used. In spite of the high thermal conductivity of a metal mesh belt of cast steel or of a mixture of cast steel and stainless steel, in the case of a one-sided texturing on the top or bottom side, the heat flow of the top and bottom side is still slightly different if the metal mesh belt, upon contacting the mat of material, has the same temperature as the steel belt. On the board side, with the metal mesh band about 2 mm thick, the heat flow is somewhat reduced, so that, in addition to the slightly reduced press factor, the density profile of the finished board is affected. Right at the start of the pressing, in the case of a high heat requirement, much heat is transported into the outer layers of the mat of material, so that these layers are softened by the heat and are more greatly compacted by the application of pressure than the cold middle layers. Even in the case of slight temperature differences at the surface of the material mat, a different cover layer density occurs, causing an asymmetrical raw density profile, which is considered undesirable by many users of the boards, since these boards more easily warp, among other things.
[0028] Therefore, it is especially advantageous that the metal mesh belt upon contacting the material mat has a temperature at least about 40° -80° C. higher than the steel belt. The heat put into the metal mesh belt then leads to an approximately uniform heat flow on the top and bottom sides of the mat, so that the problems described above are diminished. Density profile meters which are installed directly following the continuously operating press permit a continuous display of the density profile of the board just produced. By means of this density profile meter a precise adjustment of the temperature of the metal mesh belt can be performed. If in the case of an upper circulating metal mesh belt the face layer density is too low, it is possible by increased preheating of the metal mesh belt to increase the face layer density.
TABLE 1 Thermal conductivity and thermal expansion coefficient of metal mesh belts with weaving pattern typical for OSB manufacture Thermal conductivity Thermal expansion [W/m ° K] coefficient [1/K] Cast steel mesh 40 11 Stainless steel mesh 23-25 16 (high-alloy) Stainless steel warp, cast 32 16 or 11, steel filling according to direction Sandvik steel 1650 SM 16 11
[0029] The mat of material is under specific pressure during the pressing and shows a growth in width and, as for the length, at first a growth in length, and then at the end of the pressing a certain shrinkage in length. At the same time the pressed mat as bulk material and also the cured mat or hot board have substantially less stiffness than the metal mesh belt. When the pressed mat is relieved of pressure during processing, a relative movement occurs between the pressed mat and the texturing belt, causing the texture to be blurred.
[0030] In the case of the mesh texture of a Flexopan mesh as commonly used in cyclic pressing, the distance between two filling wires is about 1.7 mm. A shift of 0.2 or 0.3 mm between the filling wire and the pressed mat, if the pressure is relieved and is reapplied, or if the specific pressure is too low, would result in a visible loss of texture quality.
[0031] In other words, when a certain minimum pressure of 0.3 N/mm 2 —i.e., a normal force—is applied to the mat, the static friction between the mat and the metal mesh belt is sufficiently great so that no shift takes place between the mat and the metal mesh belt. Tests have shown that this pressure alone suffices to prevent relative movement. Toward the end of the pressing, after about 80% of the pressing time, the specific pressure may be dropped below 0.3 N/mm 2 in order to let vapor off from the hot board. After the vapor venting has begun, the specific pressure is no longer increased. So at the end of the pressing the specific pressure may be lowered without impairing the texture quality, because another subsequent application is not performed. A slight relative movement between the steel belt and the metal mesh belt is allowed in the press gap. This results in wear on the metal mesh belt. Relative movement between the metal mesh belt and the heating plate also takes place in a cyclic press in which a metal mesh belt with a temperature under 50° C. is deposited on a pressed board heated at 220° C. At this rate of wear the metal mesh belt has a useful life far in excess of a year.
[0032] The raw material mat can be sprayed with hot water or, preferably, the surface layers are preheated with steam by the method of DE 44 47 841; both methods serve to shorten the pressing time. In the continuous production of OSB, often only the top side of the raw mat is sprayed with water, since on the bottom of the mat the spray water remains on the transport belt and does not get into the hot press. In this case substantially more heat is required for the evaporation of moisture on the top surface of the mat than on the bottom surface of the mat. This heat can be supplied selectively to the mat by heating the metal mesh band circulating on top to a very high temperature.
[0033] The metal mesh belt may return through a separate heat tunnel from the entrance of the continuously operating press to a quarter of the press length, since the metal mesh belt should be heated to a higher temperature than the steel belt. The metal mesh belt is preferably drawn over a heating plate. Instead of the heating plate, heated rolls can also be used. Between the heating plate of the preheating section and the steel belt, thermal insulation should be provided, which preferably should be carried even around the entrance drum. From the first quarter to the end of the press the metal mesh belt is carried in the same insulating tunnel as the roll rods and the steel belt.
[0034] In another embodiment, the metal mesh belt can be brought to a temperature that is about 80° K higher than that of the steel belt in the entrance (about 120° C.). After making contact with the raw material mat the metal mesh belt will shrink, but this shrinkage is prevented by the steel belt. This shrinkage signifies a stretching of the metal mesh belt, but in the hot pressing operation it is still in the elastic range. After the pressure is relieved in the exit from the press the metal mesh band may shrink unhampered, since the press pressure in this area is no longer enough to harm the materials in contact with one another.
[0035] It is also appropriate to use a metal mesh belt in which the warp is made of stainless steel and the filling of cast steel. This makes it possible to obtain a metal mesh belt that has an elastic elongation of 1% lengthwise, which is useful in regulating the running of the belt and in compensating for irregularities.
[0036] In the use of the material of the metal mesh belt proposed according to the invention it is also important to consider that the metal mesh belt must be so elastic that, at the pressure acting upon it, it can greatly compensate the stresses exerted upon it. A shorter pressing time or a shorter continuously operating press can advantageously also be achieved if the spreading of the mat takes place with a moisture content of less than or equal to approximately 9 weight percent, and then water is sprayed on one or both faces or the mat as a whole, or only the faces are preheated with steam.
[0037] The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment was chosen and described to explain the principles of the invention and as a practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.
List of Reference Numbers
[0038] 1. Continuously operating press
[0039] 2. Bottom frame part
[0040] 3. Upper frame part
[0041] 4. Steel belt, below
[0042] 5. Steel belt, above
[0043] 6. Press platen, below
[0044] 7. Press platen, above
[0045] 8. Driving drum
[0046] 9. Idler drum
[0047] 10. Mat of material to be pressed
[0048] 11. Press gap
[0049] 12. Spreading station
[0050] 13. Conveyor belt
[0051] 14. Guide pulleys
[0052] 15. Metal mesh belt
[0053] 16. Isolating tunnel
[0054] 17. Guide pulleys
[0055] 18. Heating tunnel
[0056] 19. Wood material board
[0057] 20. Heating roll
[0058] 21. Heating plates
[0059] 22. Preheating system
[0060] 23. Spraying system | A continuously operating press for the continuous manufacture of wood material boards having a textured surface on at least one side includes: an upper frame part and a lower frame part; two endless steel belts configured to draw a mat of material through the continuously operating press and to transfer press pressure, each steel belt associated with one of the upper frame part and the lower frame part; an endless metal mesh belt associated with a corresponding one of the steel belts; an insulating tunnel associated with the metal mesh belt and the corresponding steel belt; and a heating tunnel associated with the metal mesh belt and separated from the corresponding steel belt. The metal mesh belt includes a material having a thermal conductivity substantially higher than that of the corresponding steel belt and having a thermal expansion coefficient approximately equal to that of the corresponding steel belt. | 1 |
CROSS REFERENCE TO RELATED PATENT APPLICATIONS
[0001] The present application is a divisional patent application of U.S. patent application Ser. No. 10/644,130 filed on Aug. 20, 2003 for a “Single Piece Packaging Container and Device for Making Same.”
BACKGROUND OF THE INVENTION
[0002] The present invention is directed to packaging containers and a device for making the containers. More particularly, the present invention pertains to configurations for a packing container having self-formed end closures, created from a single piece of material. The present invention also pertains to a device for forming the containers.
[0003] Packaging for lengthy items takes many forms. One construction includes a pair of corrugated, laminated paperboard top and bottom U-shaped channels configured for one to fit within the other. Most packages formed in this manner require separate end closures or caps, usually manufactured from cardboard or wood. These caps generally are stapled to adjacent package walls. Not only does this method necessitate close-fit manufacturing, but it is also very cumbersome at installation, and may cause content damage due to incompletely formed or off-positioned staples.
[0004] In another variety of packaging container, one of the top and bottom U-shaped channels has a notch cut into opposing side walls of the “U,” so that the “U” portion may be folded over at a 90 degree angle. In such a configuration, channel ends are closed by the folded base portion and the side walls of the “U,” which are folded over adjacent side walls. To seal such a package, tape or a like strip-type adhesive sealant must be extended over the flaps that then are folded over the adjacent side walls. Even though a seal may be formed, openings may remain at the juncture of the folded-over base portion and the cover portion, seriously weakening the package. This design is disclosed in U.S. Pat. No. 4,976,374.
[0005] Another existing packaging container, disclosed in Loeschen, U.S. Pat. No. 6,382,447, resolves the above-referenced problems by providing a packaging container in which the entirety of the end closure is formed from the packaging material itself. However, the container base unit, which forms end closures for the packaging container, features mitered corners. These mitered corners require complex die-cutting with mirrored tools, and mandatory strapping at specific positions to restrain the miter flaps. The patent to Loeschen, which is commonly assigned herewith, is incorporated herein by reference.
[0006] A new, single-piece packaging container cut without miters is disclosed in application Ser. No. 10/264,506, filed Oct. 4, 2002, assigned to the assignee of the present invention and incorporated herein by reference. The end closures of this packaging container are formed from the packaging material itself. The container allows for no gaps at its closure locations, because its end closures meet or overlap along the container's main body portion, providing a high degree of structural strength and package integrity. Manufacturing the container is extremely simple and cost-effective, requiring only two straight saw-cuts on each package end.
[0007] Occasionally, packaging containers must accommodate objects with varied local height elevations, or objects that require segregation during shipping or storage. Normally, shippers rely on foam fillers or container partitions to protect such irregularly shaped or fragile objects. Foam fillers may compress, leak, or shift, and container partitions may shift or break during shipping, rendering shippers' attempts to protect their products worthless. Accordingly, there exists a need for specialized configurations for a single-piece packaging container having self-formed end closures, providing better protection for fragile and/or irregularly shaped objects than undependable foam fillers or container partitions.
BRIEF SUMMARY OF THE INVENTION
[0008] Configurations for a packing container formed from a single, preformed, rigid unit of U-shaped cross-section having a main body portion with a bottom wall and opposing side walls, and having self-formed end closures are disclosed. The unit forms a plurality of end closures, at each end of the packaging container. Each end closure is formed from a plurality of closure panels extending from and adjacent to each end of the main body portion. The main body portion and the plurality of end closures are separated from one another by fold lines.
[0009] For purposes of the present disclosure, the package material, although defined as having a U-shaped cross-section is, in fact, formed from a material having a channel-like or squared U-shape having a flat or near-flat bottom wall. The corners may be formed having a radius of curvature (i.e., rounded) or they may be formed having relatively sharp angles. However, again, for purposes of the present disclosure, the container material is referred to as “U-shaped.”
[0010] The main body portion and the plurality of closure panels all have straight-cut corners at their junctions with each other. Some closure panels are configured for folding generally perpendicular to each other and to the main body bottom wall, and others are configured for folding generally parallel to each other and to the main body bottom wall.
[0011] In one embodiment, the packaging container is configured to enclose an object with an elevated end (e.g., a support post with an attached asymmetrical flange). One of the end closure's closure panels has approximately the same height as the elevated end of the object to be packaged. Another embodiment is configured to enclose an object with an elevated mid-section (e.g., a crankshaft with integrated cam). Additional closure panels are included with this configuration, to accommodate the “bulge” made by the object's elevated mid-section.
[0012] In another embodiment, the packaging container is configured to enclose an object with random elevations. Two of the end closure's closure panels have approximately the same height as the highest elevation of the object to be packaged. A fourth embodiment is configured to enclose two or more dissimilar objects that should be prevented from touching or intermingling during shipping in separate compartments. Another embodiment is configured to combine elements of the four above-referenced configurations, allowing a user to ship objects with elevated ends, elevated mid-sections, or random elevations in separate compartments. A sixth embodiment is configured to enclose one or more objects with a set of two closure panels that are about equal in length to one another.
[0013] These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:
[0015] FIG. 1 is a side view of a configuration for a single-piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container being shown with its first, second, and third closure panels laid open, prior to folding and securing;
[0016] FIG. 2 is a side view of the configuration of FIG. 1 , showing the packaging container enclosing an object with an elevated end;
[0017] FIG. 3 is a side view of another configuration for single piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container being shown with its first, second, and third closure panels laid open, prior to folding and securing;
[0018] FIG. 4 is a side view of the configuration of FIG. 3 , showing the packaging container enclosing an object with an elevated mid-section;
[0019] FIG. 5 is a side view of another configuration of a single piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container being shown with its first and second closure panels laid open, prior to folding and securing;
[0020] FIG. 6 is a side view of the configuration of FIG. 5 , showing the packaging container enclosing an object with random elevations;
[0021] FIG. 7 is a front view of the configuration of FIG. 5 along line 7 - 7 , showing the packaging container enclosing an object with random elevations;
[0022] FIG. 8 is a side view of another configuration of a single piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container being shown with its first, second, and third closure panels laid open, prior to folding and securing;
[0023] FIG. 9 is a side view of the configuration of FIG. 8 , showing the packaging container enclosing two objects in two separate compartments;
[0024] FIG. 10 is a side view of another configuration of a single piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container shown enclosing two objects, one with an elevated end, and the other with an elevated mid-section, in two separate compartments;
[0025] FIG. 11 is a side view of another configuration of a single piece packaging container with straight-cut end closures constructed in accordance with the principles of the present invention, the container being shown with its first and second closure panels laid open, prior to folding and securing;
[0026] FIG. 12 is a side view of the configuration of FIG. 11 , showing the packaging container enclosing an object;
[0027] FIG. 13 is a perspective view of one device for forming the cuts in the packaging container material;
[0028] FIG. 14 is a perspective view of one exemplary container having cuts formed therein;
[0029] FIG. 15 is a cross-sectional view taken along line 15 - 15 of FIG. 14 , illustrating a pair of embossings formed in the container material for enhanced container formation;
[0030] FIG. 16 is a perspective view of the cutter carriage shown with the carriage in the up or loading position;
[0031] FIG. 17 is a side view of the cutter carriage of FIG. 16 shown with the carriage moving into the down or cutting position;
[0032] FIG. 18 is a partial side view of the cutter shown with a container loaded therein and with the holding pins securing the container within the cutter;
[0033] FIG. 19 is a cross-sectional view taken along line 19 - 19 of FIG. 18 ;
[0034] FIG. 20 is a partial side view of the carriage;
[0035] FIG. 21 is a perspective view of the cutter showing the indexing assembly in the retracted position;
[0036] FIG. 22 is a perspective view of the cutter similar to FIG. 21 but showing the indexing assembly in the extended position; and
[0037] FIG. 23 is a front view of the cutter showing the scale windows through a lower portion of the carriage and the scale visible therethrough.
DETAILED DESCRIPTION OF THE INVENTION
[0038] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described presently preferred embodiments with the understanding that the present disclosures are to be considered exemplifications of the invention and are not intended to limit the invention to the specific embodiments illustrated.
[0039] It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention,” relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.
[0040] Referring now to the figures and in particular FIG. 1 , there is shown a packaging container 10 , configured to enclose an object with an elevated end (e.g., a support post with an attached asymmetrical flange) in one of the embodiments of the present invention. The packaging container is formed in a U-shaped cross-section. Preferably, the packaging container is formed from laminated paperboard material. The packaging container includes a main body portion 12 , first closure panels 14 , 16 , second closure panels 18 , 20 , and a third closure panel 22 . The straight-cut first, second, and third closure panels are formed from an extension of the main body portion 12 . The main body portion has a bottom wall 24 and side walls 26 . The first, second, and third closure panels 14 , 16 , 18 , 20 , and 22 , also have bottom walls 28 , 30 , and 32 , and side walls 34 , 36 , and 38 .
[0041] The first closure panels 14 , 16 are formed adjacent to and at either end of the main body portion 12 . The side walls 34 of the first closure panels 14 , 16 have first straight-cut corners 40 . The main body side walls 26 also have straight-cut corners 42 , immediately adjacent to the first panels' straight-cut corners 40 . First fold lines or creases 44 can be formed between the main body bottom wall 24 and the firs closure panels' bottom walls 28 at the junctures of the straight-cut corners 42 , 44 to facilitate folding.
[0042] The second closure panels 18 , 20 are adjacent to the first closure panels 14 , 16 . The second closure panels 18 , 20 are separated from the first panels 14 , 16 by second fold or crease lines 46 formed between the first closure panels' bottom walls 28 and the second closure panels' bottom walls 30 , parallel to the first fold lines 44 . The side walls 36 of the second closure panels 18 , 20 include first straight-cut corners 48 at the junctures with the first closure panels 14 , 16 . The side walls 34 of the first closure panels 14 , 16 include second straight-cut corners 50 adjacent to the second closure panels 18 , 20 .
[0043] The third closure panel 22 is adjacent to one of the second closure panels 18 . The third closure panel 22 is separated from the second panel 18 by third fold or crease lines 52 formed between the second closure panel's bottom walls 30 and the third closure panel's bottom walls 32 , parallel to the first and second fold lines 44 , 46 . The side walls 38 of the third closure panel 22 include straight-cut corners 54 at the junctures with the second closure panel 18 . The side walls 36 of the second closure panel 18 include second straight-cut corners 56 adjacent to the third closure panel 22 .
[0044] The height h 26 of the main body side walls 26 is about equal to the heights h 34 , h 36 , and h 38 of the first closure panels side walls 34 , second closure panels side walls 36 , and third closure panels side walls 38 . The length l 14 of one of the first closure panels 14 is approximately equal to the height h 52 of the object 52 (see FIG. 2 ) with an elevated end enclosed within the package 10 . The length l 16 of the other first closure panels 16 is approximately equal to the heights h 20 , h 34 , h 36 , and h 38 of the main body, first closure panels, second closure panels, and third closure panel side walls 20 , 34 , 36 , and 38 .
[0045] Referring to FIG. 2 , assembling the package 10 is straightforward and readily carried out. The package 10 is placed on a surface, with the main body 12 , and the first, second, and third closure panels 14 , 16 , 18 , 20 , and 22 , laid out flat. The article to be packaged 58 is placed in the main body portion 12 . The first panels 14 , 16 are then folded upwardly, so that the first panels 14 , 16 are perpendicular to the bottom wall 24 of the main body portion 12 . As the first panels 14 , 16 are folded, their side walls 34 can be inserted between the main body side walls 26 . The second panels 18 , 20 are then folded over, perpendicular to the first panels 14 , 16 , so that the bottom walls 30 of the second panels 18 , 20 lie substantially parallel to the bottom wall 24 of the main body portion 12 . As the second panels 18 , 20 are folded, their side walls 36 can be inserted between the side walls 34 of the first panels 14 , 16 . Finally, the third panel 22 is folded, generally perpendicular to the first closure panels 14 , 16 , generally parallel to the main body bottom wall 24 , and overlapping one of the second closure panels 20 . As the third panel 22 is folded, its side walls 38 can be inserted between the side walls 26 of the main body portion 12 . FIG. 2 shows the package 10 fully assembled and enclosing an object 58 with an elevated end. One of the corners 50 of one of the first closure panels 14 and one of the corners 48 of one of the second closure panels 18 may be trimmed to facilitate package forming.
[0046] Another embodiment of the present invention is displayed in FIGS. 3 and 4 , which show a packaging container configuration designed to enclose an object with an elevated mid-section 60 (e.g., a crankshaft with an integrated cam). Similar to the configuration shown in FIGS. 1 and 2 , the packaging container 10 includes a main body portion 12 , first closure panels 14 , 16 , and second closure panels 18 , 20 , but the present embodiment incorporates two third closure panels 22 , 23 instead of one. The lengths l 14 , l 16 of the first closure panels 14 , 16 are approximately equal to the heights h 26 , h 34 , h 36 , and h 38 of the main body, first closure panels, second closure panels, and third closure panel side walls 26 , 34 , 36 , and 38 .
[0047] Referring to FIG. 4 , to assemble the package, the main body 12 , and the first, second, and third closure panels 14 , 16 , 18 , 20 , 22 , and 23 are laid out flat on a surface. The article to be packaged 60 is placed in the main body portion 12 . The first panels 14 , 16 are then folded upwardly, so that the first panels 14 , 16 are perpendicular to the bottom wall 24 of the main body portion 12 . As the first panels 14 , 16 are folded, their side walls 34 can be inserted between the main body side walls 26 . The second panels 18 , 20 are then folded over at roughly a 45-degree angle to the first panels 14 , 16 , so that the bottom walls 30 of the second panels 18 , 20 lie at substantially at 45-degree angle to the bottom wall 24 of the main body portion 12 . As the second panels 18 , 20 are folded, their side walls 36 can be inserted between the side walls 34 of the first panels 14 , 16 . Finally, the third panels 22 , 23 are folded, generally at a 45-degree angle to the second closure panels 14 , 16 , parallel to the main body bottom wall 24 , and overlapping one another to accommodate the mid-section bulge of the object 60 . As the third panels 22 , 23 are folded, their side walls 38 can be inserted between the side walls 26 of the main body portion 12 . The second closure panels 18 , 20 may vary in length l 18 , l 20 , but together should always be equal to the length l 12 of the main body portion 12 . FIG. 4 shows the package 10 fully assembled and enclosing an object 60 with an elevated mid-section.
[0048] A third embodiment of the present invention is illustrated in FIGS. 5-7 , which show a packaging container configuration designed to enclose an object with random elevations 62 . Similar to the configurations shown in FIGS. 1-4 , the packaging container 10 includes a main body portion 12 , first closure panels 14 , 16 , and second closure panels 18 , 20 , but no third closure panels. The lengths l 14 , l 16 of the first closure panels 14 , 16 are approximately equal to the highest height of the object 62 with random elevations enclosed within the package 10 .
[0049] Two additional short slits 64 , 66 are cut into the side walls 26 of the main body portion 12 , creating small support wedges 68 , 70 . The slits 64 , 66 are positioned close to the center of the main body portion side walls 26 , and are spaced approximately two inches apart. The height h 64 , h 66 of the slits is approximately half the height h 26 of the main body portion 12 side walls 26 . Both support wedges 68 , 70 are slightly deformed inward, allowing the second closure panels 18 , 20 to rest upon them (see FIGS. 6 and 7 ) when closed.
[0050] FIGS. 6 and 7 show the packaging container 10 as assembled. The main body 12 , and the first and second closure panels 14 , 16 , 18 , and 20 are laid out flat on a surface. The article to be packaged 62 is placed in the main body portion 12 . The first panels 14 , 16 are then folded upwardly, so that the first panels 14 , 16 are perpendicular to the bottom wall 24 of the main body portion 12 . As the first panels 14 , 16 are folded, their side walls 34 can be inserted between the main body side walls 26 . The second panels 18 , 20 are then folded over, perpendicular to the first panels 14 , 16 so that the bottom walls 30 of the second panels 18 , 20 lie substantially parallel to the bottom wall 24 of the main body portion 12 . As the second panels 18 , 20 are folded, their side walls 36 can be inserted between the side walls 34 of the first panels 14 , 16 . The side walls 36 of the second closure panels 18 , 20 rest on the support wedges 68 , 70 formed in the main body side walls 26 . FIG. 6 shows the package 10 fully assembled and enclosing an object 62 with random elevations. FIG. 7 shows a front cut-away view of the package 10 fully assembled and enclosing an object 62 with random elevations.
[0051] A fourth embodiment of the present invention is demonstrated in FIGS. 8 and 9 , which show a packaging container configuration designed to enclose two related but dissimilar objects or groups of objects 72 , 74 , which should be prevented from touching or intermixing during shipping. Similar to the configurations shown in FIGS. 3 and 4 , the packaging container 10 includes a main body portion 12 , first closure panels 14 , 16 , second closure panels 18 , 20 , and third closure panels 22 , 23 . The lengths l 14 , l 16 of the first closure panels 14 , 16 and l 22 , l 23 of the third closure panels 22 , 23 are approximately equal to the heights h 20 , h 34 , h 36 , and h 38 of the main body, first closure panels, second closure panels, and third closure panel side walls 20 , 34 , 36 , and 38 .
[0052] Referring to FIG. 9 , to assemble the package, the main body 12 , and the first, second, and third closure panels 14 , 16 , 18 , 20 , 22 , and 23 are laid out flat on a surface. The articles to be packaged 72 , 74 are placed on either end of the main body portion 12 . The first panels 14 , 16 are then folded upwardly, so that the first panels 14 , 16 are perpendicular to the bottom wall 24 of the main body portion 12 . As the first panels 14 , 16 are folded, their side walls 34 can be inserted between the main body side walls 26 . The second panels 18 , 20 are then folded over, perpendicular to the first panels 14 , 16 , so that the bottom walls 30 of the second panels 18 , 20 lie substantially parallel to the bottom wall 24 of the main body portion 12 . As the second panels 18 , 20 are folded, their side walls 26 can be inserted between the side walls 34 of the first panels 14 , 16 . Finally the third panels 22 , 23 are folded, generally perpendicular to the second closure panels 18 , 20 and the main body bottom wall 24 , and generally parallel to the first closure panels 14 , 16 . As the third closure panels 22 , 23 are folded, their side walls 38 can be inserted between the side walls 36 of the second closure panels 18 , 20 . When folded, the third closure panels 22 , 23 form a double-thick divider, separating the packaged objects 72 , 74 . The second closure panels 18 , 20 may vary in length l 18 , l 20 , but together should always be equal to the length l 12 of the main body portion 12 . FIG. 9 shows the package 10 fully assembled and enclosing objects 72 , 74 that should be prohibited from touching or intermixing during shipping.
[0053] The present configuration additionally may be used as a packaging container with a built-in spacer. Frequently, objects are somewhat shorter than the length of available shipping containers. For example, it would be economical to ship an object four feet to five-and-a-half feet in length in a six-foot-long standard box. Usually, such an object would be randomly placed in a too-large box and covered with foam fillers or other, similar protective materials. However, fillers may compress, leak, or shift, leaving shipped objects without protection. Conversely, using the packaging container 10 described in FIGS. 8 and 9 , the short object could be placed against one end of the container 10 , and then custom enclosed into a segregated side, with a double-thick divider separating it from the other, fully-formed, hollow chamber. The present configuration allows shippers to customize packaging containers by creating a segregated, perfectly-sized compartment within a standard-sized box.
[0054] A fifth embodiment of the present invention is demonstrated in FIG. 10 , which shows a packaging container configuration designed to combine all four of the above described configurations. As described in detail above, the packaging container 10 exhibited in FIG. 10 can accommodate and object with an elevated end 58 , an object with an elevated mid-section 60 , an object with random elevations 62 (not shown), and objects that must be segregated during shipping 72 , 74 . To accomplish the composition of FIG. 10 , the side of the main body portion 12 containing the object with an elevated end requires four closure panels ( 14 , 18 , 22 , 76 ), and the side of the main body portion 12 containing the object with an elevated mid-section requires five closure panels ( 16 , 20 , 23 , 78 , 80 ). All of the closure panels are folded and inserted according to the above descriptions, resulting in completely object coverage and a double thick divider. If an object with random elevations 62 was packaged as part of a combination container, four closure panels would be required for its end of the container.
[0055] A sixth embodiment is presented in FIGS. 11 and 12 , which show a packaging container configuration designed to enclose one or more objects 82 . Similar to the configuration shown in FIGS. 5 and 6 , the packaging container 10 includes a main body portion 12 , first closure panels 14 , 16 , and second closure panels 18 , 20 , but no third closure panels. The lengths l 14 , l 16 of the first closure panels 14 , 16 are approximately equal to the heights h 26 , h 34 , and h 36 of the main body, first closure panels, and second closure panels side walls 26 , 34 , and 36 . In that this is a “seamless” container, the second closure panel 20 has a length l 20 that is about equal to the length l 12 of the main body portion 12 .
[0056] FIG. 12 shows the packaging container 10 as assembled. The main body 12 , and the first and second closure panels 14 , 16 , 18 , and 20 are laid out flat on a surface. The article to be packaged 82 is placed in the main body portion 12 . The first panels 14 , 16 are then folded upwardly, so that the first panels 14 , 16 are perpendicular to the bottom wall 24 of the main body portion 12 . As the first panels 14 , 16 are folded, their side walls 34 can be inserted between the main body side walls 26 . The second panels 18 , 20 are then folded over, perpendicular to the first panels 14 , 16 so that the bottom walls 30 of the second panels 18 , 20 lie substantially parallel to the bottom wall 24 of the main body portion 12 . As the second panels 18 , 20 are folded, their side walls 36 can be inserted between the side walls 34 of the first panels 14 , 16 . In that the length l 20 is about equal to the length l 12 of the main body portion 12 , the container appears to be “seamless”; that is, the container appears to be without a mid container seam across the top (which is panel 20 ) or the main body portion 12 .
[0057] Referring now to FIG. 13 , there is shown one cutter device 102 for forming or making the side wall cuts in the container 10 material. The cutter 102 includes a frame 104 , a container support 106 and a carriage 108 that moves in a reciprocating manner in the direction of the cut. As illustrated, the container support 106 includes beam 110 on which are mounted stand-offs 112 for receiving the container 10 . The container 10 rests on the stand-offs 112 to define a base surface 114 and side surfaces 116 for supporting the container 10 as it is cut.
[0058] The carriage 108 is configured to move down and up, toward and away from the container 10 as it rests on the support 106 . The carriage 108 is configured to support a pair of rotary cutters 118 , for example, circular saws, one each mounted a carriage side wall 120 . In this manner, as the carriage 108 moves up and down (as indicated by the arrow at 122 ), the cutters 118 move up and down for cutting through the side walls of the container 10 .
[0059] As best seen in FIGS. 16 and 20 , a cutting anvil 124 is positioned on the support 106 at the location at which the cutters 118 move into the container 10 . The anvil 124 includes channels 126 formed in the side walls to permit movement of the cutters 118 through the container side walls without contacting the anvil 124 side walls. In addition, the anvil 124 can include a raised portion or ridge 128 that extends transversely across the top wall 129 of the anvil 124 between the side wall channels 126 .
[0060] In a present embodiment, the carriage 108 is moved up and down by action of a drive 130 , such as the exemplary pneumatic cylinder. The pneumatic cylinder 130 is mounted to an upper carriage plate 132 to which the carriage side plates or walls 120 (mounting the cutters 118 to the carriage 108 ) are mounted. In this manner, reciprocating movement of the cylinder 130 moves the carriage 108 which moves the cutters 118 into and out of contact with the container 10 . Other drives will be recognized by those skilled in the art and are within the scope and spirit of the present invention.
[0061] The cutters 118 are fixedly mounted to the carriage 108 to permit readily moving the carriage 108 up and down for cutting the container side walls. To facilitate holding or maintaining the container 10 in place as the carriage 108 moves downward and the cutters 118 move into contact with the container side walls, a pair of holding pins 134 can be mounted to the support 106 . The holding pins 134 move outwardly to hold the container 10 side walls against the carriage side surfaces 116 as the cutters 118 make contact with the container 10 . In a present embodiment, the pins 134 are pneumatically actuated.
[0062] To further provide a “clean” container 10 appearance, the cutting device 102 is configured to emboss the container top or bottom wall 24 at fold or crease lines between the side wall cuts. As seen in FIGS. 15 and 19 , the upper carriage plate 132 includes a transverse groove 136 formed therein that corresponds to the top wall ridge 128 . In this manner as the carriage 108 moves down to move the cutters 118 into contact with the container 10 side walls, the upper plate 132 “presses” the container top (or bottom) wall 24 between the upper carriage plate 132 and the support top wall 129 , sandwiching the container wall 24 between the ridge 128 and the groove 136 , thus “embossing” a groove into the wall 24 .
[0063] To provide the appropriate spacing between cuts (e.g., to form appropriate sized panels 12 , 14 , 16 ), the cutter device 102 can include an indexing assembly 138 . The indexing assembly 138 includes a drive 140 , such as the exemplary pneumatic cylinder, to move the container 10 a desired distance once a first cut is made to position the container 10 for a second cut. To effect movement, the cylinder 140 cycles between a retracted position ( FIG. 21 ) and an extended position ( FIG. 22 ). The extension length or distance of the cylinder 140 can be set to correspond to the desired distance between cuts.
[0064] As seen in FIG. 23 , the carriage 108 can include openings or windows 142 in a side thereof that overlie a scale 144 that is applied to the support beam 110 . In this manner, the distance along the length of the container 10 at which the cut or cuts are formed can be precisely set and controlled.
[0065] All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure.
[0066] In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.
[0067] From the foregoing, it will be observed that numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims. | Configurations for a packing container formed from a single, preformed, rigid unit of generally U-shaped cross-section are disclosed. One configuration utilizes three end closures to enclose an object with an elevated end. Another configuration employs three end closures to enclose an object with an elevated mid-section. A third configuration uses two end closures to enclose an object with random elevations. With three end closures, a fourth configuration encloses two or more dissimilar objects in separate compartments. The fourth configuration is especially useful for items that should be prevented from touching or intermingling during shipping. A fifth configuration combines elements of the other four configurations, allowing a user to ship objects with elevated ends, elevated mid-sections, or random elevations in separate compartments. A sixth configuration encloses one or more objects with two end closures that are about equal in length to one another. A device for forming the container is also disclosed. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to a gas turbine turbojet with an upstream fan and to a method of mounting an electric current generator in the turbojet.
Some of the power generated by an aeronautical turbojet engine is used to power various parts both of the turbojet and of the aircraft propelled in full or in part by that turbojet.
Some of this power is currently taken off the high-pressure (HP) compressor, the compressed air of which is used, particularly for pressurizing and conditioning the cabin of the aircraft, or alternatively for de-icing. Some of this power is taken mechanically off the shaft of the HP stage of the turbojet to drive the input shaft of an accessories gearbox positioned on a casing of the turbojet. This input shaft is rotationally driven by a transmission shaft extending through a structural arm of the casing and itself driven by a pinion secured to the HP shaft.
There is a current trend toward increasing the installed electrical power so tapping mechanical power from the engine is anticipated.
However, drawing too much mechanical power has a detrimental effect on the operation of the HP spool because it is liable to adversely affect engine operability, particularly when the engine is running at low speed.
DESCRIPTION OF THE PRIOR ART
Patent Application FR 2882096 discloses taking some of the mechanical power off the low-pressure (LP) spool to drive the rotation of the input shaft of an accessories gearbox. A solution such as this entails structural modifications to the LP shaft 2 by adding a power transmission pinion to it. A system such as this is difficult to assemble because it involves moving around metallic parts that are bulky and heavy.
Patent Application WO2007/036202 also discloses mounting an electric current generator in the turbojet spool. The generator is made up of a stator element positioned circumferentially in the compression casing of the turbojet, and of rotor elements fixed to the ends of blades secured to the HP shaft and rotationally driven in the compression casing of the turbojet.
The rotational movement of the rotor elements induces a current in the stator element, which current is transmitted to the various pieces of equipment that require power. A current generator such as this is difficult to access and entails partial disassembly of the turbojet when it needs to be replaced or serviced. The compressor casing is of a small size, making it complicated to route the generated current to the various pieces of equipment.
SUMMARY OF THE INVENTION
In order to alleviate at least some of these disadvantages, the applicant company has proposed a twin-spool gas turbine turbojet comprising a high-pressure rotor and a low-pressure rotor, the low-pressure rotor shaft being connected, at its upstream end, to a fan housed in a fan casing, which turbojet comprises, upstream of the fan, a fixed cowl element centered on the axis of the engine and on which there is mounted an electric current generator designed to take mechanical power off the low-pressure rotor shaft and convert it into electrical power.
The turbojet advantageously allows power not to be taken from the HP rotor shaft. The current generator is simple to access, allowing it to be replaced in a limited length of time by dismantling a minimum number of turbojet components.
The current generator is positioned upstream of the fan, in a cool region of the turbojet, thus reducing its need for cooling and therefore its mass.
The current generator comprises a stator element connected to the fixed cowl element, and a rotor element driven by the upstream end of the low-pressure rotor shaft.
According to one embodiment, the turbojet comprises a fan disk on which the fan blades are mounted. A rotor element of the current generator is rotationally driven by a journal secured to said fan disk.
The cowl element is advantageously connected to the fan casing by radial retaining arms.
The radial arms allow the stator element of the generator to be held securely without requiring substantial structural modifications to the turbojet.
Ducts for lubricating the current generator and electric cables are formed in the radial retaining arms.
According to another embodiment, power transmission pinions are formed respectively on the rotor element of the current generator and on the upstream end of the low-pressure rotor shaft, the pinions meshing with one another in order to transmit the rotational movement of the low-pressure rotor shaft to the rotor element of the current generator.
The invention also relates to a method of mounting a current generator in the fan of a gas turbojet, in which:
the current generator is mounted on the fixed cowl element; the fixed cowl element is positioned on the fan in such a way that the rotor element of the generator is in register with the upstream end of the low-pressure rotor shaft; and the cowl element is immobilized on the fan casing with the radial retaining arms.
The generator is simple to mount and this mounting is performed upstream of the turbojet. The components that need to be handled are small in size and light in weight thus allowing the current generator to be replaced quickly.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages will emerge from the following description of the turbojet of the invention with reference to the figures in which:
FIG. 1 depicts a sectioned view of the upstream part of a turbojet according to the invention with a current generator positioned in the fan of the turbojet;
FIG. 2 depicts a close-up view of the current generator of FIG. 1 ;
FIG. 3 depicts another embodiment of the invention; and
FIG. 4 depicts a general arrangement of the turbojet of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1 , the turbojet of the invention is a twin-spool gas turbojet 100 comprising a low-pressure (LP) rotor and a high-pressure (HP) rotor 1 , which are mounted so that they can rotate about the axis X 3 of the turbojet. This type of turbojet is well known to those skilled in the art. The terms internal or external, inner or outer, when used in the description, will be understood to mean radially internal or external or on the inside or the outside of the turbojet, with respect to the axis X 3 thereof.
More specifically, with reference to FIG. 4 , the turbojet functionally comprises, from the upstream direction downstream in the direction in which the gases flow, a fan 10 , a compressor, a combustion chamber, a turbine and a jetpipe. As it is a twin-spool engine, it comprises an LP compressor upstream of an HP compressor, and an HP turbine upstream of an LP turbine.
The fan 10 in FIG. 1 comprises a fan disk 19 attached by a flange to a journal 15 , itself supported by a bearing secured to the intermediate casing, the journal 15 here being secured to the low-pressure shaft 2 .
The fan 10 further comprises a moving cowl element 11 which is fixed to the fan disk 19 . The moving cowl element 11 is of frustoconical shape and guides the incoming air stream. A fixed cowl element 12 is positioned upstream of the moving cowl element 11 .
The fan 10 is rotationally driven inside the fan casing 14 by the LP rotor shaft 2 which rotates as one with the moving cowl element 11 . A housing 13 is formed in the moving cowl element 11 .
With reference to FIG. 1 and more specifically to FIG. 2 , an electric current generator 20 is mounted on the fixed cowl element 12 , the generator 20 comprising a stator element 21 , firmly attached to the fixed cowl element 12 , and a rotor element 22 free to rotate with respect to the fixed cowl element 12 .
In this instance, the rotor element 22 is an electromagnet extending axially along the axis X 3 . The stator element 21 is made up of windings which extend coaxially with respect to, and on the outside of, the rotor element 22 . A bearing 23 supports the rotor element 22 as it rotates in the stator element 21 .
As the electromagnet 22 rotates about the axis X 3 , a magnetic field is created and induces an electric current in the windings 21 .
Radial retaining arms 16 structurally connect the fixed cowl element 12 to the fan casing 14 , the stator element 21 of the current generator 20 thus remaining immobile as the fan blades 18 rotate. The retaining arms 16 are attached by a flange to the fan casing 14 .
The retaining arms 16 are advantageously hollow and can house ducts 41 for lubricating the current generator 20 and electric cables 42 depicted in FIG. 2 . The upper retaining arm 16 is depicted showing hidden detail over part of its length so that the ducts 41 for lubricating the current generator 20 and the electric cables 42 may be seen.
The ducts 41 for lubricating the current generator 20 allow a lubricant, such as oil, to be carried from an oil tank, positioned downstream of the fan, to the current generator 20 to cool and lubricate the current generator 20 .
Once the current generator 20 has been cooled, hot oil flows through the retaining arms 16 thus de-icing the arms and cooling the oil. Such lubricating ducts 41 make it possible to reduce the size of the heat exchangers needed for cooling said oil.
The electric cables 42 allow the current generated in the windings 21 to be led away to electrical equipment positioned downstream of the engine.
The retaining arms 16 of the fixed cowl element 12 in this instance are shaped so as to conduct the incoming air stream toward the fan blades 18 . The retaining arms 16 are three in number here, spaced 120° apart. It goes without saying that this number may change according to the configuration of the engine.
In this exemplary embodiment, the rotor element 22 is connected directly to the upstream end of the low-pressure rotor shaft 2 . Power transmitting bevel gear pinions 25 , 26 are formed respectively on the rotor element 22 of the current generator 20 and on the upstream end of the low-pressure shaft 2 , the pinions 25 , 26 meshing with one another in order to transmit the rotational movement of the low-pressure shaft 2 to the rotor element 22 of the current generator 20 .
As the turbojet engine 100 runs, the low-pressure rotor shaft 2 is rotationally driven by the low-pressure turbine of the turbojet 100 .
The low-pressure rotor shaft 2 rotates the electromagnet 22 about the axis X 3 and induces an electric current in the windings 21 of the current generator 20 . The current is carried by the retaining arms 16 of the fixed cowl element 12 via the electric cables 42 positioned in the arms 16 , the equipment situated mainly downstream of the fan therefore being supplied with electric current.
In another form of embodiment, with reference to FIG. 3 , an additional journal 17 is mounted between the fan disk 19 and the rotor element 22 of the current generator 20 , the fan disk 19 supporting the fan blades 18 . The journal 17 , which rotates as one with the LP rotor shaft 2 , drives the rotation of the rotor element 22 .
The journal 17 is connected by a screw-nut connection to the fan disk 19 and to the rotor element 22 . The way in which the current generator 20 is fixed with the fixed cowl element 12 remains the same; it is only the way in which the rotor element 22 is driven that differs from the previous embodiment.
The invention also relates to the method of mounting the current generator 20 in the turbojet 100 .
The current generator 20 is mounted on the fixed cowl element 12 . The current generator 20 is screwed to the cowl in this instance.
The fixed cowl element 12 is positioned on the fan 10 in such a way that the rotor element 22 of the generator 20 is in register with the upstream end of the low-pressure rotor shaft 2 .
The power transmitting bevel gear pinion 25 of the stator element 22 is brought into register with the power transmission bevel gear pinion 26 of the low-pressure rotor shaft 2 .
The fixed cowl element 12 is then immobilized on the fan casing 14 with the radial retaining arms 16 .
The ducts 41 for lubricating the current generator 20 are connected to the current generator 20 in order to supply the current generator 20 with oil, the electric cables 42 being connected to the windings of the stator element 21 of the current generator 20 so as to carry the current to the various pieces of equipment of the aircraft. | A twin-spool gas turbine turbojet comprising a high-pressure rotor; a low-pressure rotor; a low-pressure rotor shaft connected to a fan housed in a fan casing; and a fixed cowl element centered on the axis of the engine, upstream of the fan, on which there is mounted an electric current generator designed to take mechanical power off the low-pressure rotor shaft and convert it into electrical power. | 5 |
BACKGROUND OF THE INVENTION
Devices incorporating wireless communications techniques are becoming increasingly prevalent in modern society. An inevitable result of this trend is that frequency spectrums are becoming more crowded and prone to interference. At the same time, consumers are becoming increasingly concerned about the privacy and security of wireless communications. Consequently, systems engineers designing a variety of wireless communications systems, including cellular and cordless telephones, to are increasingly turning to digital spread spectrum signaling methods to achieve greater security, higher signal-to-noise ratio, and more efficient bandwidth utilization than can be achieved by using conventional signaling methods, such as amplitude or frequency modulation without bandwidth spreading.
One popular spread spectrum signaling technique is known as frequency-hopping spread spectrum (“FHSS”). FHSS systems operate by rapidly changing their tuning frequency in a known pattern, referred to as the hop sequence. Multiple users each using different hop sequences can communicate simultaneously over independent communications channels on a single frequency range. However, because FHSS systems rely on the receiver and transmitter rapidly tuning to the desired frequency, many prior art designs require that significant microcontroller processing time be devoted to repeatedly programming a phase-locked loop to tune new channels.
Consequently, one object of the present invention is to provide a hardware-implemented phase-locked loop controller for programming a phase-locked loop, thereby allowing the general purpose microcontroller to devote its processing power to implementing more advanced functionality.
When designing wireless communications systems using portable units, the battery life of the portable unit is a key design parameter. Some prior art FHSS portable units significantly extend their battery life by periodically entering a “sleep” mode, in which many system components are de-powered. However, the portable unit's responsiveness is often significantly compromised, because upon “awakening” from sleep mode the unit must perform a complete resynchronization procedure before to communication with the base unit can resume. Other systems may continuously maintain synchronization albeit at the expense of decreased battery life. It is therefore an object of this invention to provide a phase-locked loop (PLL) controller which allows a transceiver to enter a very low power sleep mode, and yet resume communications immediately upon awakening.
Another aspect of FHSS systems which is especially advantageous is the ability to avoid interference on a particular frequency channel by dynamically changing the channels in the hop sequence, substituting a new “clear” channel frequency for an detected “bad” channel frequency. Therefore, another object of the present invention is to allow simple implementation of dynamic channel allocation.
Phase-locked loop circuits may require specific configuration programming prior to use. Designers may also wish to allow for specific control of the phase-locked loop during diagnostic or other modes of operation. Consequently, it is an object of the present invention to allow for an override of the default hardware-controlled phase-locked loop programming sequence.
Furthermore, in designing a digital wireless communications system, it is often desirable to allow a portable unit to communicate to any one of a plurality of base units spread throughout a region, such as in the case of the implementation of a cellular telephone system. This configuration allows a user of the portable unit to communicate throughout a wide area, while requiring only enough transmit power to reach the nearest base unit. Consequently, portable unit battery life is improved, and interference with other nearby users of the frequency band is decreased. However, to implement such functionality in a FHSS system, transceivers in the portable and base units must have synchronized hop sequences such that a portable unit will be able to communicate to any base unit which is loaded with the same hop sequence. It is therefore an object of this invention to provide a hardware-implemented PLL controller with hop synchronization ports which may be used to synchronize the hop sequences of multiple units in a system.
These and other objects of the present invention will become apparent in light of the present specification and drawing.
SUMMARY OF THE INVENTION
In accordance with the invention, a hardware implemented phase-locked loop controller is provided which utilizes an indirect addressing scheme to access PLL data for repeated programming of a phase-locked loop at a fixed rate. The invention consists of a hop counter, a pattern register, a PLL data table, and a data control circuit.
The hop counter periodically increments its state between zero and a specified maximum value. Upon reaching the maximum value, the counter state is reset back to zero. In accordance with one aspect of the invention, the hop counter may maintain hop sequence synchronization while a transceiver is placed in a low-power sleep mode, thereby allowing instantaneous resumption of communications upon awakening. In accordance with another aspect of the invention, the hop counter may provide for synchronization between multiple transceivers in a communications system. The hop counter can generate a sync signal upon reaching its maximum state, which can be transmitted to additional transceivers in the system to force the simultaneous reset of additional hop counters.
The pattern register is an addressable memory area addressed by the hop counter, which outputs channel numbers comprising the hop sequence. In accordance with one aspect of the invention, the pattern register may include an input whereby an external circuit can write new values to locations in the pattern register, thereby enabling the implementation of dynamic channel allocation techniques without interrupting communications.
The PLL data table converts the channel number to which the phase-locked loop is to be tuned, into the control words which tune the phase-locked loop to the desired frequency. The specific control words may vary according to the design of the phase-locked loop circuit.
The data control circuit provides a programming interface to send the PLL data table output to the phase-locked loop device. For example, many phase-locked loop devices are programmed via a serial programming interface, in which case the data control circuit may include a parallel to serial converter, and may further synthesize clock and frame signals as required by the PLL programming model. Optionally, the data control circuit may also provide signals to control RF circuit functionality, as is desired to effectuate a proper channel change. Finally, the data control circuit may include provisions for an overriding input, through which an external circuit can control the PLL programming regardless of the PLL data table output.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of one embodiment of the invention, as implemented in a frequency hopping radio system with an external microcontroller which sets the number of frequencies in the hop pattern, and implements dynamic channel allocation, which embodiment also controls auxiliary external circuits via dedicated control lines.
FIG. 2 is a schematic block diagram of another embodiment of the invention, as implemented in a frequency hopping radio system which also allows an external microprocessor to override the default controller operation and program the PLL, which embodiment also controls auxiliary external circuits via a serial interface common to the PLL.
DETAILED DESCRIPTION OF THE INVENTION
While this invention is susceptible to embodiment in many different forms, there are shown in the drawings and will be described in detail herein several specific embodiments, with the understanding that the present disclosure is to be considered as an exemplification of the principle of the invention and is not intended to limit the invention to embodiments illustrated.
FIG. 1 of the drawings illustrates an embodiment of the present invention comprising a hardware-implemented phase-locked loop (“PLL”) controller. Specifically, the PLL controller utilizes an indirect addressing scheme to access PLL data for repeated programming of a PLL at a fixed rate according to a specified sequence of tuning frequencies.
FIG. 1 is a schematic block diagram of the PLL controller 10 , and the interconnection between PLL controller 10 and related external circuitry, including PLL 41 and optional microcontroller unit (“MCU”) 40 . PLL controller 10 is composed of hop is counter 20 , pattern register 21 , PLL data table 22 , and data control circuit 23 .
Hop counter 20 includes a counter which increments its state at regular periodic intervals. As commonly implemented in a frequency hopping radio system, hop counter 20 will increment many times per second. When the state of hop counter 20 reaches a maximum state, it is reset to zero and counting up begins anew. The specified maximum state can either be predetermined, or can be set by optional external MCU 40 via connection 32 . Connection 32 will generally consist of an electrical connection between MCU 40 and hop counter 20 whereby MCU 40 can program a maximum number of states for hop counter 20 .
In some implementations, such as in systems with multiple transceivers, hop counter 20 may include hop synchronization input 30 and hop synchronization output 31 . A signal applied to hop sync input 30 forceably resets the hop counter state. Similarly, hop sync output 31 provides a signal after hop counter 20 reaches its maximum state. In a system with multiple transceivers, hop sync output 31 of a first transceiver can be applied to hop sync input 30 of a second transceiver, thereby causing multiple transceivers to step through their respective hop sequences synchronously.
The aforementioned hop sequence synchronization between transceivers can provide several advantages in a communications system involving one or more portable units communicating with multiple base units. The advantages stem from the fact that when hop sequences are synchronized throughout such a system, any portable device can communicate with any base unit by simply loading a common hop sequence. For example, in an office wireless telephone environment, a pool of available base units can be dynamically allocated to corresponding portable units based on portable unit demand, thereby enabling system implementation with a reduced number of base units. Also, by providing multiple base units dispersed throughout the system coverage area, a portable unit need only transmit with sufficient power to be adequately received at the nearest available base unit. The reduced transmission power increases portable unit battery life, and reduces interference with other nearby devices operating simultaneously on the same frequency band. Furthermore, as a portable user moves away from one base unit and towards another, the call can be seamlessly “handed off” between base units without interruption by loading the portable unit's hop sequence into the initiating base unit before ending the connection with the terminating base unit.
Another feature of PLL controller 10 is that hop sequence synchronization can easily be maintained during low-power “sleep mode” operation of a handset transceiver. By maintaining power to only hop counter 20 , hop counter 20 will remain synchronized with other devices in the system, except to the extent that any frequency drift of the oscillator internal to hop counter 20 relative to the other devices causes inaccuracies. Other transmit and receive circuitry can therefore be de-powered when not needed to conserve power and maximize battery life. Communications may resume immediately upon the transceiver awakening to full power mode by limiting sleep periods to a length after which any slight frequency drift that has occurred requires only bit alignment rather than a complete sync reacquisition. The acceptable maximum sleep time will depend upon the hop counter oscillator precision and transmission rate (or bit period), and can be determined by one of ordinary skill in the art.
The output of hop counter 20 is electrically connected to the address input of pattern register 21 . Pattern register 21 stores the frequency channel numbers comprising the hop sequence in consecutive memory locations. The output of pattern register 21 therefore provides a frequency channel number to PLL data table 22 . Pattern register 21 may optionally include memory write port 33 . Memory write port 33 allows external circuitry, such as MCU 40 , to change the frequency channel contained in any given memory location of the pattern register. Memory write port 33 therefore allows convenient implementation of various dynamic channel allocation techniques. Dynamic channel allocation is an advantageous feature of frequency-hopping radios whereby the effects of fixed-frequency sources of interference or channel degradation can be avoided by removing the frequency upon which communications are impaired from the hop sequence, and replacing it with a new frequency. When interference on the new frequency is less than that on the channel which it replaced, the overall quality of the communications link has been improved. Channel evaluations and allocation decisions are made by MCU 40 in the embodiment illustrated. Several dynamic channel allocation methods are known in the art.
PLL data table 22 contains the PLL command words necessary to program the PLL to each frequency channel. It outputs the command words which program PLL 41 to the frequency indicated by the channel number received from the pattern register. The exact content of the command words will depend upon the design and programming model of the particular PLL utilized, as is known by one of ordinary skill in the art.
The output of PLL data table 22 is electrically connected to data control circuit 23 , which actually programs the phase-locked loop device 41 via interface 35 . Data control circuit 23 performs the format conversions and implements the programming interface required by the PLL 41 programming protocol. For example, many phase-locked loop devices are programmed via a serial programming interface, in which case the data control circuit includes a parallel to serial converter, and synthesizes clock and frame signals for transmission via interface 35 .
Wireless communication devices commonly include both transmitter and receiver circuits. Accordingly, the present invention could be utilized by one of ordinary skill in the art in numerous embodiments to control both transmit and receive PLLs. For example, in an embodiment in which transmit and receive communications are time domain duplexed, and a single PLL is utilized for both transmit and receive circuits, the output of PLL data table 22 may include both transmit and receive PLL programming words. Data control circuit 23 then sequentially programs PLL 41 to the transmit and receive frequencies. Alternatively, if separate PLLs are utilized for transmit and receive circuits, an embodiment of the invention may be utilized which incorporates parallel receive and transmit PLL data tables and data control circuits, such that each PLL is driven by a common hop counter and pattern register, but programmed by separate data tables and control circuits. Such alternative embodiments are within the scope of this invention, inasmuch as they would be known to one of skill in the art in view of the disclosure provided herein.
Additionally, data control circuit 23 optionally provides signals to control miscellaneous aspects of RF circuit functionality. For example, it may be desirable to de-power a transmitter and/or receiver during periods of nonuse to conserve power and prolong battery life. Furthermore, t is often desirable to de-power a transmitter while the PLL is changing frequencies, so as to avoid unwanted energy transmission on spurious frequencies during the PLL tuning acquisition. In such example, data control circuit 23 may include miscellaneous control line 36 connected to RF circuit power supplies 42 as depicted in FIG. 1 . Data control circuit 23 may then assert line 36 to deactivate supplies 42 , thereby turning off the transmitter, before programming PLL 41 with a new tuning. Control circuit 23 can then de-assert line 36 to reactivate supplies 42 after the PLL has locked on to the new frequency, thereby resuming transmission at the new frequency. FIG. 2 illustrates an alternative embodiment in which external power supplies 42 are a node on a common serial programming interface 35 , in which case supplies 42 are addressed and controlled via serial commands from data control circuit 23 .
Finally, data control circuit 23 may optionally include an overriding input 34 , as depicted in FIG. 2 . Override input 34 allows external circuit MCU 40 to directly control the output of data control circuit 23 , regardless of commands received from PLL data table 22 . This feature can be used, for example, to send initialization commands to PLL 41 upon device power-up, or for providing a diagnostic test mode of PLL operation.
The foregoing description and drawings merely explain and illustrate the invention and the invention is not limited thereto except insofar as the appended claims are so limited, inasmuch as those skilled in the art, having the present disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention. | A phase-locked loop controller for a frequency hopping communications system which utilizes an indirect addressing scheme to access PLL data is provided. The controller is hardware-implemented, with little or no microcontroller processing overhead required. The controller enables simple synchronization with other units in a communications infrastructure implementation. The controller provides a simple interface for implementing dynamic channel allocation methods. An override port allows external control of the PLL with which the controller is associated. Finally, the controller can control auxilliary aspects of system operation, such as powering down a transmitter while changing PLL tuning. | 7 |
FIELD OF THE INVENTION
This invention relates to a discharge, or fluorescent, lamps, and more particularly to discharge lamps where the color of the light emitted can be controlled
BACKGROUND OF THE INVENTION
As is well known in the art, fluorescent lamps come in all sorts of different tones or colors of white. Even though they all appear to be white, their color temperature varies anywhere from 2500 to about 6000 or even 8000 and 10,000 Kelvin (herein defined as degrees Kelvin). Herein "color temperature" is related to the temperature of black body which would give an equivalent tone of white light. In general, the lower the color temperature the redder the tone of the white light, and conversely the higher the color temperature the bluer the tone of the white light. There is no specific component in the lamps having a temperature equal to the color temperature--the term is a standard used in the industry to compare the color of various fluorescent (and for that matter incandescent) lamps. The drive for different colors of fluorescent lamps derives from our familiarity with the redder, warmer incandescent lamps and our desire to have the more efficient fluorescent lamps mimic this warmer light in certain instances. This is due to the fact that the market requirements differ greatly as to the degree of whiteness that is required for different situations. For example, offices use mostly high color temperature fluorescent lamps somewhere in the vicinity of 4100 or even 5000 Kelvin. Part of the reason for the higher color temperature requirements is that these lights tend to be somewhat closer to sunlight and therefore they induce alertness and crisp daylight ambiance or atmosphere. On the other hand, in applications where somewhat softer moods or after work atmosphere is more appropriate the color temperature of the light source is typically reduced to about 2500, 2700, or 3000 Kelvin. Those lamps tend to give a light color which is somewhat closer to sunset or dusk or to incandescent lamps that people are used to at home.
Discharge lamps with different color temperatures are obtained by blending different phosphors which under identical ultraviolet excitation give somewhat different colors. Therefore, a discharge lamp must be replaced by a lamp with a different phosphor blend to produce a different color light. The color of that lamp is fixed and determined by the choice of the phosphors, and that is the reason different color temperature lamps are on the market in separate bulbs.
Generally speaking, 80% or so of the sales of discharge lamps is for lamps with color temperature range from about 3000 to 5000 Kelvin. This 2000 Kelvin range provides a quite perceptible range of different colors. However, there are some sales for lamps with a color temperatures below 3000 Kelvin, and some sales for lamps with color temperatures well above 5000 Kelvin.
Typically, residential applications tend to prefer the lower color temperature fluorescent lamps either in the circleline or in the compact fluorescent configuration. The compact fluorescent lamps (CFL) that penetrate the residential market have color temperature in the 2700 to 3100 Kelvin range which gives a reddish quality to the white light. The content of red in these residential lamps is higher than the lamps found in offices or other such business applications. In the residential market of today, the available varieties of colors is acceptable, in fact, it is preferable. It is an object of the present invention to provide a color variable CFL for use in the kitchen area, the hall area, or in the rooms where lights stay on for a long period of time. In such settings, the residential customer is provided with the desirable (and marketable) advantage of changing the color of the light without replacing the bulb to provide different moods during the course of the day and over different seasons.
Prior attempts to make a variable color temperature fluorescent lamp have, for one reason or another, never been commercialized. In many of these cases the structures of these ideas are not practical, economical, or not amenable to efficient manufacturing. The remaining cases have other performance limitations which preclude commercial success. For example, it is well known in the art of fluorescent lamps that if one increases the temperature of the lamp the amount of mercury, which is in the vapor phase, increases substantially producing more of the blue mercury lines which increases the color temperature, and so the light appears more bluish. This does change the color of the light; however the life of the lamp is markedly reduced, and the additional energy supplied (to raise the temperature of the mercury) reduces efficiency (defined herein as the ratio of the light intensity emanating from the lamp compared to the electrical power supplied to the lamp).
Another attempt to provide variable color light from discharge lamps has been to use multiple lamps of different color temperatures side by side and/or mixed in a fixture. In order to use such a fixture, one lamp of one color temperature is fully energized and the other is not fully energized. By changing the power distribution between the two lamps, e.g. a low temperature (reddish) and a high temperature (bluish) lamp, it is possible to make the fixture emit light of different colors. This is a brute force approach whereby the lamps are not deployed at their full efficiency. Both lamp life and the efficiency are reduced when lamps are operated in this mode. Furthermore, one would need to sell a whole fixture with a variety of lamps in order for this variable color to be deployed. Another disadvantage of this approach is that one end of the fixture emanates a different color than the other end of the fixture due to the physical position of the two lamps in the fixture. Also, since one lamp is not fully energized one end of the fixture is brighter than the other end in addition to the color difference. This approach, from an aesthetic point of view, is not an acceptable solution and it has not resulted in a successful product.
Another device that provides variable color light from discharge devices is shown in U.S. Pat. No. 5,363,019, entitled, VARIABLE COLOR DISCHARGE DEVICE, to Itatani et al., and assigned to Research Institute for Applied Sciences, of Kyoto Japan. This patent issued on Nov. 8, 1994. This inventive device used a mixture of two gases that, when excited, provide different color discharge light. The gases are controlled by electric fields.
It is an object of the present invention to overcome this limitation by providing a single variable color temperature lamp having a coating of a fixed blend phosphor or layers of such coatings on the lamp bulb. A related object is to provide a lamp with multiple coatings of different phosphors or combinations of phosphors or blends of such phosphors.
It is an object of the present invention to provide a lamp where the color can be changed without substantial loss of efficiency and/or life and to provide a practical system that can be manufactured with existing technology.
It is yet another object of the present invention to provide a variable color fluorescent lamp with a variable color temperature that extends from at least 3000 to 5000 Kelvin. A related object is to provide variable color temperature fluorescent lamps wherein each lamp may have a variable color temperatures range a few hundred to several thousand degrees Kelvin.
SUMMARY OF THE INVENTION
The preceding objects are met by a variable color temperature regular or compact fluorescent lamp. A variable color lamp is defined herein as a fluorescent lamp whose color temperature can be controlled at will by externally varying a parameter of the electrical driving signal to the lamp such as: current, voltage, the frequency of the signals, use of intermittent signals or signals with pulse segments, where the type of pulse segment, is described by characteristics such as rise times, fall times, amplitudes, electrical signal waveform shapes and the like. The variations of the drive signal cause the spectral emissions from the mercury to have corresponding different amounts of energy in the various spectral lines. By coating the lamp bulb with phosphor blends or layers that preferentially react to the different spectral lines a mechanism is created that allows changes in the external electrical drive signal to result in different colors of light emitted from the lamp. The invention applies to all known fluorescent lamps, of any shape, size, power, and configuration. Furthermore, an advantage of the present invention is that the variable color lamp can be made with existing technology.
Herein, type A is used therein to specify, generally, those materials which absorb and respond to a range of incident radiation around 254 nm, and type B to materials that have reduced absorption and response to the 254 nm range of type A, but do respond to other radiation wavelengths, e.g. 365 nm and/or 185 nm. However, the use of type A and/or type B and/or type C herein are simply to designate separate phosphors or blends. No limitation is suggested as to use of type A, B or C, herein. Many different phosphors and blends of phosphors can be used to advantage within the scope of this invention, all that is required of the different phosphors and blends thereof is that they can be mixed or overcoated upon one another, and where each has a different absorption spectrum and emission spectrum compared to any other.
The objects are met in a discharge lamp including a chamber (or bulb) with transparent walls, said chamber sealed to the atmosphere, a mixture of a rare gas, e.g. krypton, argon, or substantially any of the noble inert gases, and mercury contained within the chamber, a first phosphor or phosphor blend (type A) covering a first portion of the chamber wall, a second phosphor or phosphor blend (type B) covering a second portion of the chamber wall, and where said first and second portions may overlap and range independently from a small area of said inner chamber wall to substantially the entire chamber wall, two electrodes extending into the chamber through said walls with external electrical contacts, means to drive an electrical signal from one contact through the chamber to the second contact, and means to control the electrical signal such that the phosphors are preferentially excited such that the phosphors will produce different wavelengths and quantity proportions of visible light. In other preferred embodiments a third phosphor or phosphor blend, covering a third portion of the chamber wall is implemented in addition to the first two, and where the portion of the chamber wall may overlap and range independently from a small area to substantially the entire area. In yet other preferred embodiments additional phosphors or phosphor blends may be used.
There are no variable color temperature fluorescent lamps on the market--likely due to the technological and cost challenges involved in making such a lamp. The present invention provides substantial advantages over currently existing products. These advantages are:
1. Customers would have access to a variety of color temperatures in one lamp that they can alter at will depending on their needs, application, time of day, and season. This advantage is likely to command a substantial premium over existing products in the marketplace. Furthermore, customers will be able to create special effects by emphasizing certain color temperatures in one part of the space and other color temperatures in other parts.
2. From the manufacturing and distribution point of view, the costs of supplying one lamp rather than the eight or ten different color temperature lamps now being supplied will reduce costs that will result in a lower price to the customer.
3. Manufacturing costs associated with making variable color temperature lamps are likely to be significantly less. This is due to the fact that every time there is a changeover for making the same lamp in a different color temperature one loses labor time, machine time, and materials such as phosphor and glass scrap. Overall shrinkage, that is lamps and components that are scrapped due to poor quality, during the transition is likely to drop significantly. It is self evident that making a single type and a single color lamp (or two or three different lamps) is easier and cheaper than making a multiplicity of color temperature lamps. Therefore, everything else being equal, a single phosphor system lamp is cheaper to make.
4. Components costs are likely to drop. Purchasing and blending eight to 10 or more different phosphors each at different quantities is more expensive than purchasing and blending only two or three phosphors, each at proportionally higher quantities to make the same number of lamps. This increase in quantity typically translates to lower price. Therefore, savings should be realized due to this scale up in purchased components.
Other objects, features and advantages will be apparent from the following detailed description of preferred embodiments thereof taken in conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a fluorescent or discharge lamp according to a first preferred embodiment;
FIGS. 1A and 1B show a portion of the coated wall section of the FIG. 1 devices (at A/B) and illustrate two variant embodiments wherein a two phosphor layer coating (FIG. 1A) and a three phosphor layer coating (FIG. 1B) are provided in contrast to a single coating of blending phosphors in FIG. 1;
FIG. 2 is a block diagram of the circuitry driving the lamp of FIG. 1;
FIG. 3A and 3B are excitation spectra for some type A phosphors;
FIG. 3C is the corresponding emission spectrum of the type A phosphors of FIGS. 3A and 3B;
FIG. 4A is the emission spectrum for a lamp with type A phosphor including the blue spectral emission lines from mercury;
FIG. 4B is the drive waveform used to produce FIG. 4A spectrum;
FIG. 5A is the excitation spectrum for a type B phosphor;
FIG. 5B is the emission spectrum of the type B phosphor of FIG. 5A;
FIG. 6A-6H are some electrical drive waveforms used to drive the fluorescent lamps;
FIG. 7A is the emission spectrum from a lamp with a phosphor blend of 80% type B and 20% type A;
FIG. 7B is the drive waveform to produce the spectrum of FIG. 7A;
FIG. 7C is the emission spectrum from a lamp with a phosphor blend of 80% type B and 20% type A;
FIG. 7D is the drive waveform to produce the spectrum of FIG. 7C:
FIG. 7E is the difference spectrum between FIGS. 7C and 7A, showing the emissions added by the pulsed drive of FIG. 7D;
FIG. 8 is a graph of the changes in color temperature against proportions of phosphors of type A to type B, and including differences due to electrical drive waveforms; and
FIG. 9 is a graph of the changes in illumination against proportions of phosphors of type A to type B, and including differences due to electrical drive waveforms.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1, 1A, 1B show the fundamental elements of a discharge lamp 2. As is well known, a low pressure mercury/rare gas 4 discharge constitutes the heart of a fluorescent lamp. Electrodes 6 protrude through the glass envelope 8 and these electrodes are connected to an AC power source, see FIG. 2. An electrical discharge between the two electrodes 6 within the envelope excites the mercury to produce, quite efficiently, 254 nm (nanometer) radiation which is one of the fundamental resonance lines of mercury. The rare gas, typically argon or krypton, is used to prevent the rapid deterioration of the electrodes 6 during operation. This 254 nm radiation impinges upon the walls of the tube which are typically coated 12 with a phosphor material. The phosphor particles absorb the ultraviolet (254 nm) photons and converts them to visible radiation. Depending on the phosphor matrix, as well as the doping concentrations therein, a shade of white or any other color can be generated. Examples of dopants which could be used herein are: Eu, Tb, Ce, Mn, Gd, and the like. As stated above and as appears in more detail hereinafter, the phosphor coating comprises multiple distinct phosphor choices that can be a single layer 12 of blended phosphors as illustrated in FIG. 1, a layered coating arrangement 12A as in FIG. 1A comprising a glass substrate 12G as part of the envelope overlaid with phosphor layers 12A1 and 12A2; or a layered coating arrangement 12B as in FIG. 1B comprising coating layers of phosphors 12B1, 12B2, 12B3 on the envelope wall. Stippling is shown in the envelope in FIGS. 1, 1A, 1B to illustrate the discharge 4 generally.
Green, red, or purple fluorescent light sources for specialized applications have been produced. As mentioned above, the white light could vary anywhere from color temperatures of 2000-2500 Kelvin to about as high as 10,000 Kelvin. This is accomplished by changing the concentrations of the dopants and the proportions of the phosphor blend that produce blue, green and red colors. Again, as mentioned above, once the phosphor is deposited on the surface of the glass and baked, it becomes a permanent part of the lamp and therefore, when operated as in the prior art, the color is fixed. In addition to the above sources of emitted light, often some of the higher energy states of the mercury atoms are excited that emit blue and green colors or lines (line herein is defined as the spectral line associated with electrons falling from higher energy states to lower energy state with a concomitant release of light). These line colors are taken into account to determine the ultimate color of the emitted light from a manufactured lamp.
FIG. 2 shows in block diagram form, an arrangement suitable for powering a discharge lamp used in accordance with the present invention. The electrodes 6 are heated to thermionic emission by the supplies 14 connected to the external portions 10 of the electrodes. The function generator 16 and a power amplifier 18 form a flexible system to produce electrical signals to drive the lamp. These components (16, 18) may be arranged to modify the electrical signals to change the color temperature and so the emitted light of the discharge lamp 17. Once a desired lamp color temperature has been determined an electronic ballast circuit can be synthesized to operate the lamp at that desired color temperature using present technology as in ballasts which control fluorescent lamp operation today.
Other means to produce excited mercury atoms without using electrodes, say by electromagnetic means, may be used to advantage within the scope of this invention.
It is known that the mercury atom can be placed in excited conditions where the atom's electrons have been displaced into higher energy states compared to an unexcited condition of the atom. It is also known that these excited atoms will spontaneously return to their unexcited states and will emit spectral lines that are characteristic of the specific energy states. The mercury spectral lines (in nanometers) having useful intensities and of interest are: 185, 254, 365, 407, 435 and 546. It has been discovered that by changing the driving scheme of the lamp, that is the way the discharge lamp is powered, that the proportional intensity of light emitted among these spectral lines can be changed. There is a relationship between the way the lamp is driven and the intensity of light generated in these spectral lines.
In order to use the above discovery to advantage, phosphors were obtained that respond preferentially to the various spectral lines and to produce different color temperatures and so different emitted light color. The scheme works as follows (using the mercury lines as the phosphor excitation radiation): FIG. 3A and 3B shows the excitation spectrum of typical phosphors used in fluorescent lamps. NP 92 is a blend of NP220 shown in FIG. 3A and NP340 shown in FIG. 3B. NP refers to phosphors produced by the Nichia Co. of Japan. Both of these phosphors respond substantially to the 254 mercury spectral line, and both output significant light intensity around 611 nm and 544 nm. Another phosphor, e.g.(Y,Ba)2SiO5:Ce (refered to herein as YBA), produced by the Nemoto Phosphor Co. of Japan, has a reduced excitation response to the 254 nanometer mercury resonance line but is substantially excited by the 365 nanometer radiation was developed. The excitation curve of this phosphor is shown in FIG. 5A, and the corresponding emission spectrum is shown in FIG. 5B. From inspection of these curves it can be seen that this phosphor responds significantly to the 365 nm but insignificantly to 254 nm, and this phosphor outputs light around 420 nm. When two phosphors are blended, one which is excitable primarily by the 254 nm and the other by the 365 nm mercury line, and if each of these phosphors are preferentially excited in a controlled manner that the color of the emitted output light from these phosphors can be controlled. YBA is not the only phosphor of type B that can be used. Other phosphors include ZnS:Ag, ZnS:Cu, BaAl 12 O 19 :Mn, and similar phosphors.
In prior art, normal conditions of operation are where the mercury emits primarily 254 nm, only phosphor emissions as in FIG. 3C would be useful (type A). Typically about 90% of the radiation which is emitted by mercury is in the 254 line under AC or DC normal, continuous wave operation. Therefore, as a result of this normal operation only phosphor type A is excitable producing the regular white light which is the basis of the fluorescent lamp. Now if the excitation mode is changed to a pulse scheme or a number of other such schemes which will be described later on the mercury 365 line can be increased to a higher percentage. For example, under prior art normal conditions only 2% of the total radiation is in the 365 line, but by pulsing or burst pulsing the driving electrical signal into the lamp the 365 line radiation can be increased to about 10% of the total emitted radiation. Now the second phosphor type B is excitable, and the radiation of the second phosphor (type B) is added to the radiation of phosphor type A. This, in many cases, is sufficient to change the color temperature of the lamp enough to satisfy most user's needs. Furthermore, by changing the frequency and the excitation mode of the driving electrical signal the amount of 365 nm radiation produced can be varied from 2% to 10% on a continuous basis depending on the amount of power that is introduced. The phosphor blend can be selected with reasonable efficiencies that provide a color change especially in the 3000 to 5000 K. range. A preferred embodiment includes phosphors selected from Sr5(PO4)3Cl:Eu, (Y,Ba)2SiO5:Ce, LaPO4:Ce,Tb, and Y2O3:Eu.
If the majority of the radiation is obtained from the 254 nm via the first phosphor type A, which has a high efficiency then the loss of efficiency in the lamp as a result of changing the excitation scheme (to obtain color change) is relatively minimal. This is true because up to ninety percent of the light intensity still comes from the 254 nm radiation. This embodiment results in use of an ordinary, prior art, regular lamp with a fixed phosphor blend which under certain excitation schemes emits light of one color temperature and, as the excitation scheme is altered, it emits light of a different color temperature. The advantages in this approach are that: the lamp is manufacturable, using existing technology, therefore it is relatively low cost; only the driving scheme needs to be re-configured probably using an electronic circuit excitation; and for color temperature changes within the limits of market requirements there is no substantial loss of efficacy. These features and advantages make the present invention very attractive and practical.
In one preferred embodiment the phosphors are blended, but in another preferred embodiment the phosphors are applied as separate layers. Another preferred embodiment is as follows: a layer of ZnS (zinc sulfide) phosphor is first coated on a glass; a layer of NP92 overcoats the first layer (NP92 has green and red rare earth phosphor components). This embodiment resulted in a color temperature change of about 1200° K. between a continuous excitation and a pulse burst excitation. There was a 15% decline in efficacy. ZnS was chosen because of its strong absorption at 365 nm and weak absorption at 254 nm. A third embodiment includes the additional third layer overcoating the two layer mentioned just above. This third layer was YBA which was added to absorb the 185 nm radiation (not shown in the drawings). This third embodiment also provided a substantial color temperature change. Within the scope of this invention there are numerous combinations of phosphors and blends thereof that exploit the extra ultraviolet radiation emitted under the pulse drive electrical signals described herein. In addition, additional layers beyond three can be used to advantage within the scope of the present invention.
An important aspect of this invention is that, when color change of the emitted light from a lamp is desired, the present invention generates proportionally more 365 nm radiation compared to 254 nm radiation. For example, the 365 nm radiation intensity can rise five-fold from two to ten percent, while the 254 nm radiation may change by only a few percent.
The mercury 254 nm radiation line (line refers to radiation or light emanating at a fixed frequency) originates at the lowest excited state above the ground state at an energy level of 4.86 eV. In order to generate the 365 nm line, an energy level of nearly 9 eV has to be attained. By using a pulse or pulse burst drive, more mercury atoms can be excited to the higher energy levels required for the increased 365 nm radiation production and the corresponding color temperature change described in this invention. Within a drive scheme employing pulses, there are many ways to shape the pulses or the burst of pulses. Some of these schemes are more efficient and/or practical for the production of non 254 nm mercury lines than the others as described later.
FIG. 3A, 3B and 3C show the normal, prior art phosphor type A excitation and emission spectra which is used in most fluorescent lamps. This phosphor is called a rare earth tri-phosphor. FIG. 4A shows the normal mercury/noble gas emission spectra whereby a majority of the emissions is due to the type A phosphor conversion of 254 nm radiation. FIG. 4B shows the electrical driver voltage and current waveforms used to generate the emission of the lines of FIG. 4A. The driver waveforms shown are similar to those obtained from a commercial electronic ballast. The parameters of the electrical waveform in FIG. 4B are 20 kHz at eight watts.
FIG. 5A shows the new phosphor which has been used in an embodiment of the present invention. This is a commercially available phosphor obtained from Nemoto Phosphor Company which is presently used in a variety of non-lamp applications. However this phosphor is compatible with the lamp environment, and this phosphor is typically tailored to respond to 365 nm excitation. FIG. 5B shows the emission spectrum of the phosphor which is in the blue visible region. Other phosphors, excitable by 365 nm excitation, are available that emit visible light in the green, red or some other part of the spectrum. For example the phosphor ZnS:Cu,Al (zinc sulfide, copper aluminum) emits green, YVO4:Eu (yttrium vanadate europium) emits red, and ZnS:Ag,Cl (zinc sulfide, silver chlorine) emits blue. Finally, combinations of these foregoing phosphors will emit light combination to achieve a variety of colors. In addition, there are many other phosphors, known in the art, that one could employ within the scope of this invention to maximize the absorption of 365 nm excitation and emit visible light. See FLUORESCENT LAMP PHOSPHORS, by Keith H. Butler, published by Pennsylvania State Univ. Press, 1980.
Finally, FIGS. 6A-H shows some examples of pulse burst excitation waveform signals used to drive the lamp that augment 365 nm emission of a mercury/rare gas discharge. Herein, pulse burst is defined to include a range of pulses from a single pulse to a multitude of pulses. Rounded or sinusoidal waveshapes are found in the forms of FIGS. 6A and 6B. A pulse segment is herein defined as a single pulse starting at the base line and ending when the base line is encountered twice more. Rise times are accentuated in triangular shapes or forms of FIG. 6E and F, and rise and fall times are accentuated in the rectangular or square shapes of FIG. 6G and 6H. FIGS. 6B, D, F, and H exhibit pulse burst or intermittent waveform signals. Intermittent waveform is herein defined as a waveform comprising a series of pulse burst separated from each other. A preferred embodiment of the present invention uses combinations of these drive signals where the intermittent signals are substituted for the continuous waveform signal of FIG. 6A when a color temperature change is desired. In fact combinations of the various continuous signals and the pulse or intermittent signals can be used within the scope of the present invention. For example, one combination may be a continuous waveform, used for given color temperature, with a change to a drive waveform comprising a pulse or intermittent waveform superimposed on the continuous waveform which yields a changed color temperature. Other combination includes a change from a given continuous waverform to an waveform comprising alternating periods of two other different waveforms. In fact any combination of separate pulse waveforms and composites of different pulse burst waveforms, including periods of no drive signal interspersed among the pulse waveforms, can be used to advantage in the present invention.
In another preferred embodiment a fluorescent lamp made in accordance with the present invention may be driven by a low amplitude electrical drive signal that maintains a low level of excitation of the mercury and a corresponding low level of light emitted by the phosphors. This drive signal is described in the art as a "keep alive" or "simmer" signal. Actual power levels in a simmer operation of a lamp range from a few percent upwards to well over ten percent, with ten percent being most common. In this state an intermitent signal may be used such that a low level of light is generated. Typical operation might be to have the simmer signal for 14 ms (milliseconds) followed by a 1 ms pulse burst. One benefit of use of such a signal is to avoid the condition when a lamp is fully off and high voltage is needed to cause the mercury to be excited. This high voltage may have some long term detrimental effects on the electrodes.
FIG. 7A shows the emission spectrum of a lamp with a blended phosphor which contains about 20% of the type A variety and 80% of the type B variety by volume. FIG. 7B shows the typical, prior art sinusoidal, continuous waveform operation that produces the emission spectrum of FIG. 7A. FIG. 7C shows the emission spectrum under sinusoidal pulse burst scheme excitation shown in FIG. 7D. FIG. 7E shows the difference between the two spectra of FIG. 7C and 7A. FIG. 7E shows a fair amount of blue (in the 400-440 nm range) emission of the phosphor blend and some additional mercury visible lines that have been excited by the pulse excitation. It should be noted that only positive differences, i.e., where the spectral output from pulsing is more than for continuous operation, are shown in FIG. 7E. This lamp was operated at 8 watts.
FIG. 8 shows the change of color temperature as a function of composition of phosphor type A and phosphor type B. As the phosphor type B percentage composition increases, the color temperature is increased, and the controllable range of color temperatures is larger. The largest color change for a given phosphor blend was obtained when bursts of fast rising triangular pulses were used, these waveforms are shown in FIG. 6F. The change of color temperature shown in FIG. 8 is with respect to symmetrical continuous sine wave of 50 kHz at a lamp power of 8 W. The base line of this graph represents the color with the continuous sinusoidal waveform, where the diamond shaped indicators lie. The lamp was operated at 9 W with the fast rising triangular pulse burst excitation of FIG. 6F, and the resulting color temperature change for each blend is indicated by the dot. As mentioned earlier, any waveform that results in a relative increase of 365 nm, 185 nm and mercury visible lines compared to 254 nm radiation can be used to advantage by the present invention.
FIG. 9 shows the change in relative illuminance as a function of percentage composition of type A and B phosphors and under the drive conditions and waveforms as described in FIG. 8. The diamond indicators are along the top axis, zero percent, which is the base line. The changes in illumination due to fast rising triangular pulse burst excitation of FIG. 6F are indicated by the dots.
The techniques of applying the phosphor in layers or in a single layer of a mixture or blend is well known in the art, and such techniques can be used advantageously with the present invention.
EXAMPLE OF A PREFERRED EMBODIMENT LAMP
A tubular FL (fluorescent lamp) was prepared from a glass tube of 0.7" OD and 8" long. The phosphor powders were mixed in a lacquer solution (solvent plus binder) as per standard practice for wet coating applications. Two different phosphor solutions were prepared, as follows
______________________________________PHOS- MANUFACTURER EXCITATION EMISSIONPHOR (designation) PEAK (nm) PEAK (nm)______________________________________TYPE A NICHIA (NP92) 254 544, 611TYPE B NEMOTO (YB-A) 365 420______________________________________
The two phosphor types were then mixed and made into 3 different blends in volumetric ratios for use in fluorescent lamps for generating different colors.
TYPE A: TYPE B
20:80
50:50
80:20
After coating the glass tubes with the phosphor blends, the tubes were dried and baked in an oven to remove the binder and solvent. The electrode glass stem assembly was sealed at each end of the tube. The lamps were then processed by standard techniques to activate the emission material of the electrode coils and then tipped off with a fill of 3 torr of argon as a buffer gas. It can be seen that, except for the special phosphor that is used, capable of selective excitation by 365 nm radiation, the lamp construction and manufacturing techniques are standard industry practices.
For lamp operation, the drive consisted of a Hewlett Packard pulse/function generator (8116A) and a high frequency amplifier (ENI 1040L) connected to the lamp. The electrode heating currents were supplied by separate circuits consisting of a 6 V battery in series with a rheostat and ammeter. The lamp electrical characteristics were measured with a true RMS VAW meter (Yokogawa 2532), oscilloscope (LeCroy 9304M), 100X Tektronix voltage probe and 10:1 current transformer (Pearson 411).
Spectral measurements were done using a Lighting Sciences system which consists of a computer controlled CCD camera that views a diffracted image of the lamp.
The normal operation of the lamp was by driving it with a sinusoidal waveform of frequency 50 kHz. This is equivalent to operating the lamp on a commercial electronic high frequency ballast. The system described above allowed the waveform to be changed to triangular shape and the rise time to be varied. It allowed for continuous (CW) or pulse burst operation. The lamp data includes operation with sinusoidal or triangular waveshapes, continuous or pulse burst operation, rise times normal (i.e., symmetric to fall time) or fast and at slightly different powers.
For the lamp described here, a symmetric, sinusoidal 50 kHz operation at 8 W is described as "normal" operation and is the reference case for the color change experiments.
It should be pointed out that the two phosphors may not necessarily be in very close proximity. For example, one phosphor could be applied to the inside of the arc tube and the second phosphor which is excited by longer wavelength radiation could be applied to the outside of the arc tube. In such a case, there would be a need for another jacket which would protect the second phosphor. Alternatively the second phosphor could be applied to the inside of the outer jacket and the space between the two bulbs could be evacuated. These and many other particular configurations constitute other preferred embodiments of the present invention. The invention as mentioned above includes utilization of two different phosphors which have somewhat different excitation regions and emission regions thereby resulting in a color change upon altered excitation.
It should be noted that mixing more than two phosphor types as well as coating more than two layers of different phosphors types (e.g. three layers, each layer of different absorption and emission spectra) is within the scope of the present invention. A particular embodiment is a three layer configuration of type A responding only to 254 nm, type B responding only to 365 nm, and a type C responding only to 185 nm excitation.
It is important in the present invention to have the electrical drive waveforms to have fast rise time pulses to generate fast electrons. These fast electrons change the prior art electron energy distribution function, and this change results in excitation of the upper energy states of mercury. Excitation of these upper energy states is important in the preferential generation of 185 nm, 365 nm, 546 nm, 437 nm and 404 nm radiation because these particular lines originate from upper excited states of the mercury atom. The literature contains numerous ways of changing the electron energy distribution, see PROGRESS IN LOW PRESSURE MERCURY-RARE GAS DISCHARGE RESEARCH, by J. Maya and R. Lagushenko, published in Advances in Atomic, Molecular and Optical Physics. This reference cites several of those techniques. The scope of the present invention includes these approaches as regards to the generation of proportionally higher percentage of upper excited states of the mercury other than the 6 3 P resonance state which emits the 254 nm radiation. Again, in addition to the phosphors utilized in these experiments, additional phosphors, that are excitable by other wavelengths which result from the pulse excitation or the change in the electron energy distribution function, can be used to advantage in the present invention.
A well known problem of fluorescent lamps concerns electromagnetic interference (EMI) which results whenever a system includes pulses, fast rise time and high frequencies. Usually in such systems there is a certain amount of both radiated and conducted EMI. Both the FCC and the FDA have standards which limit telecommunications interference and health hazards, respectively. These limits are set for industrial, commercial and residential applications of electronic and other equipment, and these standards must be met for a practical, commercial fluorescent lamp.
There are several techniques and technologies that have been utilized in the marketplace to avoid EMI both in the radiated and conducted modes. For the radiated suppression of EMI: grounding the external metallic coverings and screens, covering all openings, together with the use of high permeable materials, such as mu-metal and the like have proved successful in these applications. For the conducted EMI: there are circuits and power line filters that have proved sufficient in the industry to suppress the conducted EMI. Therefore application of these known techniques and materials will be sufficient to reduce the EMI to acceptable ranges.
It will now be apparent to those skilled in the art that other embodiments, improvements, details and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent, which is limited only by the following claims, construed in accordance with the patent law, including the doctrine of equivalents. | A fluorescent lamp (2) having at least two phosphor coatings (12) on the surface of the sealed lamp bulb, typically an inner surface. There is variable driving means which preferentially activates one phosphor and not the other phosphors, at one arrangement or setting or configuration of the driving means, while at another setting the driving means activates in addition a different or several different phosphors. Each phosphors may be a blend of phosphors and the phosphors and/or blends may be overcoated upon one another forming multiple layers or all mixed together and applied as a one layer coating on the lamp surface. The inventive lamp uses standard fabricating techniques and materials, but allows the user to change the color temperature of the lamp by controlling parameters of the electrical driving signal, that is the, spectrum and quantity of light emitted are changed in response to the changed driving signal such that the user can arrange the light output to be more or less blue or red or to balance the longer wavelengths perceived against the shorter wavelengths perceived. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application represents a continuation application of and claims priority to U.S. patent application Ser. No. 14/173,166, entitled “Domestic Clothes Dryer and Method for Driving Such Dryers”, filed Feb. 5, 2014, currently pending, and further claims priority from European Patent Application 13154316.7 filed on Feb. 7, 2013, both of which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to clothes dryers and, more particularly, to clothes dryers that distribute air through one or more lifters.
BACKGROUND
[0003] JP-A-9056991 describes a lifter fixed at the periphery part of a rotary drum and cylindrical seals are fixed at the outer periphery of an air intake plenum and of an air exhaust plenum, so that a circulation passage is formed on the back of the rear wall of the drum. The use of two concentric air plenum chambers and related seals makes the above known solution quite complex and not easy to be implemented. Moreover in the above known solution the process hot air is flowing always and entirely through the lifters, even if the lifters are in an upper position during drum rotation. In this condition, i.e. when the lifters are not in contact with clothes, the effectiveness of having air flowing in the lifter is substantially reduced. Another disadvantage of the above known solution is that it cannot be adapted to traditional dryers where air flow enters the drum from a perforated rear wall and leaves the drum from an aperture placed adjacent the front opening of the drum.
SUMMARY
[0004] It is an object of this disclosure to provide a tumble clothes dryer that does not present the above disadvantages and which can provider higher drying performances, better fabric care and reduced wrinkles.
[0005] The above object is reached thanks to the features listed in the appended claims.
[0006] One of the most relevant technical features of a dryer according to this disclosure is the use of a distribution device in the air inlet plenum chamber capable of delivering air to the drum either indirectly, i.e. through one or more lifters, or directly, i.e. though a rear perforated wall of the drum.
[0007] According to this disclosure, the distribution device is a shaped air plenum chamber which faces only a lower portion of the rear perforated wall, from its side opposite to the drum, so that air is delivered to the drum only though the lower portion of the rear perforated wall. Therefore, when the position of the lifter during rotation of the drum corresponds to the shaped air plenum chamber, air is flowing entirely or partially through the lifter, and when the position of the lifter does not correspond to said air plenum chamber, air is flowing through the plurality of holes of the rear wall of the drum facing the shaped air plenum chamber. The shape of said plenum chamber, together with the shape of an air conveying base portion of the lifter orthogonal to the active portion of the lifter on the drum side wall (such base portion covering, at a predetermined distance, a part of the perforated rear wall of the drum in order to create a sort of inner chamber) will be responsible on the amplitude of arc during which air is delivered through the lifter.
[0008] In one example, the shape of the base portion of the lifter covers substantially a circular sector covering from 60° to 100° of arc of the perforated rear wall of the drum, while the air plenum chamber covers an area a bit wider than said base portion of the lifter, so that at least a percentage of process air flows always through the perforated wall also when the lifter, during its rotation with the drum, it is in a lower portion of the drying chamber. This has been found beneficial in terms of drying efficiency and energy saving.
[0009] The use of lifters for blowing air into the drum as described herein can be implemented without significant modification of existing machines. Moreover, as described herein the air is flowing through the lifter only if this latter is aligned with the distribution device (i.e. inlet air plenum chamber). In this way air flows in the lifter only when this latter is in contact with clothes, i.e. in the lower part of its circular trajectory.
[0010] Another advantage derives from use of a dedicated cycle and the use of separate actuation for drum tumbling and air blowing that enables energy saving and reduced fabric shrinkage. For instance, the use of “blowing lifters” (i.e. use of lifters though which process air can be fed to the drum) increases significantly the drying evenness with respect to traditional dryers, particularly because air flows where it is needed, towards clothes placed in the bottom of the drum, on the lifter, where in the above known solution most of the air would flow through the upper lifter and only a limited part would flow through clothes therefore reducing significantly the efficiency of the overall drying process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Further advantages and features of this disclosure will be clear from the following detailed description, with reference to the attached drawings, in which:
[0012] FIG. 1 is an isometric view of an example clothes tumble dryer;
[0013] FIG. 2 is an isometric enlarged view of the inside of the drum of FIG. 1 ;
[0014] FIG. 3 is an isometric view of the rear of the drum of FIGS. 1 and 2 ;
[0015] FIG. 4 is a partial cross-sectional view of a detail of FIG. 2 ;
[0016] FIG. 5 is a front view of the perforated rear wall of the drum where the shape of the distributor is shown in solid and dotted line; and
[0017] FIG. 6 is a schematic view of how a clothes dryer according to this disclosure works.
DETAILED DESCRIPTION
[0018] With reference to FIG. 1 , an example tumble dryer 10 includes a cabinet 12 having an upper wall 12 a, a front wall 12 b provided with a hingedly mounted door 14 , side walls 12 c and a rear wall 12 d. Inside the cabinet 12 a rotating drum 16 is mounted which is actuated by an electric motor (not shown) and which defines a drying chamber 17 . The drum 16 includes at least one lifter 18 having a plurality of holes 20 for air passage. The lifter 18 may be hollow. The lifter 18 includes a rear base portion 18 a covers a portion of a rear perforated wall 16 a of the drum in order to convey air entering through the perforated wall 17 a towards the holes 20 of the lifter 18 . The rear base portion 18 a may have a triangular or circular sector shape. The base portion 18 a defines with the facing portion of the rear wall 16 a of the drum 16 a sort of inner chamber 19 (see FIG. 4 ) which covers an arc ranging preferably from 60 to 100° and which communicates with the portion of the lifter 18 fixed to the side wall of the drum 16 . The clothes dryer 10 may also have a dispensing system for dispensing treating chemistries into the drum 16 , and including a reservoir 22 that is closed by a cover 24 . The clothes dryer 10 is also provided with a controller 26 that may receive input from a user through a user interface 28 for selecting a cycle of operation.
[0019] The clothes dryer 10 also includes an air inlet channel 30 (see FIG. 6 ) and an outlet channel 32 , a heating system (not shown) that heats air entering the drum (e.g. by means of resistors, heat exchangers, etc.), and a blower (not shown) that makes air flowing across the drum 16 .
[0020] The drum outlet 32 , where a removable filter 33 for removing fluff or lint is placed, can be eventually connected to the drum inlet 30 thus realizing a closed loop system in which heat exchangers, resistors, heat pump, etc. control the condensation and heating process. As an alternative the drum outlet 32 can be connected to an air vent.
[0021] The lifter 18 functions not only to increase the heat exchange efficiency between air and clothes and improve the evenness of the drying result by means of clothes redistribution during the whole cycle, but also to improve the efficiency of hot air distribution.
[0022] A common drawback of known dryers is that when the load size increases to almost fill the drum volume, the efficiency of the lifter in redistributing the load within the drum is decreased thus leading to the risk of damaging the clothes that are positioned in the rear end of the dryer (where temperatures are higher) and reducing the evenness of drying results.
[0023] With a lifter design that allows not only the hot air to flow through the lifter 18 but also by means of a distribution of air through the lifter 18 only during a certain degree of rotation of the drum 16 , the temperature gradient in the drum 16 is reduced and the evenness of drying is increased, reducing also the risk of clothes damaging.
[0024] The above controlled distribution is carried out by means of a shaped fixed distributor 34 which forms an air inlet plenum chamber upstream the drum 16 . The shape of the distributor 34 ( FIG. 5 ) does not corresponds necessarily to the circular sector shape of the base portion 18 a of the lifter 18 , but need not extend higher than the lower half of the drum 16 . In FIG. 5 , two shapes are shown (in dotted and solid lines) which have worked well in tests carried out by the applicants. Such shapes maximize the air flow either though the lifter 18 (when this latter is in the lower positions during rotation) and through clothes adjacent the lifter.
[0025] In other examples, the enhanced lifter design can be combined with a dedicated cycle design, able to stop tumbling when the lifter 18 is located in a position that minimizes the temperature gradient. This approach can furthermore increase the above mentioned advantages and can provide also energy saving benefits due to reduced motor usage. One or more lifters of the type disclosed above can also be used together with one or more typical lifters that do not match the above description. Due to the fact that the lifter 18 is physically connected to the drum 16 , during tumbling it changes its position with respect to the air inlet 34 thus leading to a variable air mass flow rate in the lifter 18 and in the drum 16 . This is clearly shown in FIG. 6 where arrows A show the air flow through the lifter 18 (when this latter is placed in the lower position inside the drum 16 ), and arrows B show the air flow through the rear wall 16 a of the drum 16 when the lifter 18 is in a position not matching the air distributor 34 . This alternating air flow path in the drum 16 creates the conditions for a variable heat flux as well that improves the evenness of drying and fabric care.
[0026] The examples disclosed herein can improve significantly also the drying and fabric care performances with delicate cycles. As described above, aiming to reduce the mechanical action on this type of loads, the tumbling is often reduced or even avoided; this solution has the negative result of increasing the temperature gradient thus leading to the already discussed drawbacks. If the proposed lifter design is used, the machine can be designed to stop tumbling (for the whole cycle or only for part of it, also e.g., using a PWM approach) in a way that the air can flow through the lifter 18 to provide a means to optimize heat flux for these type of loads using appropriate design of the lifter. In some examples, the drum 16 is in a position where the lifter 18 lays on the bottom of the drum 16 , thus having the clothes laying on it. The method used to stop the drum 16 in the correct position is well known in the art and it can be easily transferred from the known solutions for top loader washer for having the door in upwards location to facilitate loading and unloading of the drum.
[0027] Moreover, since air can flow through the lifter 18 , the latter can be designed to host a cartridge containing a fragrance or some other chemical additives to improve quality of drying that can be released in the drum 16 .
[0028] In some examples, the lifter 18 is used with a drum 16 having an air inlet and outlet port on opposite sides thus enabling fine optimization of heat fluxes. Nevertheless the examples disclosed herein can be applied to those drums in which inlet and outlet air connections are located on the same side (with a dedicated air collector similar to air distributor 34 ). In these examples the lifter 18 can be used to convey hot inlet air towards the opposite side of the drum 16 , therefore improving significantly the heat flux distribution in the longitudinal direction.
[0029] FIG. 4 shows a detail of the air distributor 34 which is made preferably by a shaped metal or plastic sheet 35 . In order to increase the efficiency, a sealing means (not shown) can be interposed between the edge of the shaped sheet 35 forming the distributor 34 and the rear wall 16 a of the drum 16 . | A domestic clothes dryer comprises a rotating drum defining a drying chamber, an air inlet upstream the drum and at least a hollow lifter mounted in the drum, wherein said hollow lifter is in communication with the air inlet for distributing air inside the drum through a plurality of openings. The air inlet comprises a shaped air plenum chamber facing a lower portion of a rear perforated wall of the drum and capable of delivering air to said lifter and/or directly to the drum through said rear perforated wall. | 3 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of German patent application 10 2005 049 436.6, filed Oct. 15, 2005, herein incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for operating a textile machine having a plurality of workstations, and more particularly to such a method wherein the workstations comprise exchangeable components, each having a readable and writable transponder arranged on the exchangeable components or integrated therein. The present invention further relates to a textile machine for carrying out the referenced method, and more particularly to such a textile machine comprising a plurality of workstations, each case having one or more exchangeable components with a readable and writable transponder.
BACKGROUND OF THE INVENTION
[0003] A method for preparing a subsequent treating or processing operation of a textile bobbin is known from German Patent Publication DE OS 37 32 367 wherein a readable and writable electronic memory chip is arranged on the textile bobbin or the tube thereof. The memory chip is used to store specific information for the respective textile bobbin produced on a textile machine, such as the production date, the production time, the production site, the machine number, the batch number, the fiber material, the yarn length and the like. However, information about the number of completed clearer cuts or the number of yarn breaks eliminated which occurred during production of the textile bobbin and which are relevant to the subsequent treating or processing operations, is also recorded.
[0004] A method for operating an open-end spinning mechanism is known from German Patent Publication DE 197 55 060 A1, in which an identification marking which is configured as a transponder or as a barcode, is arranged on a spinning rotor. The transponder and also the barcode are used as information carriers of product data specific to the spinning rotor, such as the year of construction, type, size or the like. This readable information is used to avoid faulty use of a spinning rotor type when installing the spinning rotor in a workstation of an open-end spinning mechanism. This serves to ensure that the correct spinning rotors in terms of spinning technology are always used for the respective yarn batch. The transponder used is provided with a permanently stored coding which only allows the specification of the spinning rotor.
[0005] The method proposed according to German Patent Publication DE 197 55 060 A1 only provides for the identification of the spinning rotor used against the background of safety and production aspects.
[0006] It is known from German Patent Publication DE 101 17 095 A1 to provide exchangeable machine components of a textile machine with an identification marking. The identification markings are configured as colour markings which are read out by means of an optical recording system. The information read out allows conclusions in the manner already mentioned about the nature and the type of exchangeable component. In this manner, the sensible use of components on the textile machine is to be ensured in terms of spinning technology, as already known from German Patent Publication DE 197 55 060 A1. German Patent Publication DE 101 17 095 A1 also only discloses the possibility of identification of an exchangeable component against the background of safety and production aspects.
SUMMARY OF THE INVENTION
[0007] The present invention is therefore based on the object of providing a method and a textile machine for carrying out the method, whereby the automatic recording of data influencing the wear of an exchangeable component is made possible.
[0008] This object is achieved by providing an improved method for operating a textile machine having a plurality of workstations, wherein the workstations comprise exchangeable components, which in each case have a readable and writable transponder which is arranged on the exchangeable components or integrated therein. According to the method of the present invention, during the lifecycle of the exchangeable components at least the operating data which influence the state of wear of the exchangeable components and can be recorded for these during the period of use thereof are automatically stored on the respective transponder. The present invention further provides an improvement in textile machines for carrying out the present method, characterised in that at least one transceiver for writing and reading the transponders attached to the exchangeable components or integrated therein is arranged in the region of each workstation.
[0009] Further advantageous configurations, features and advantages of preferred embodiments of the method and textile machine of the present invention are described more fully hereinafter.
[0010] According to the present invention, it is proposed that during the lifecycle of the exchangeable components, at least the operating data which directly influence the state of wear of the exchangeable components and can be recorded for these during the period of use thereof are stored on the transponder. The operating data to be recorded are, for example, data such as the tonnage processed with the respective components, optionally broken down over a plurality of batches and the number of operating hours during which the components were used. Likewise, the conditions of use under which the exchangeable components were used may be recorded, such as, for example, the rotational speed during the processing of a batch, the average rotational speed over the period of use or the total period of use of the components. However, the number of yarn breaks or the clearing cuts in relation to the period of use of the components may also be recorded in the respective transponder.
[0011] The operating data recorded over the lifespan allow assessment of the degree of wear-dependent behaviour of the exchangeable components under different conditions of use. In this manner, quality profiles can be set up for the respective components and this allows optimisation of the exchangeable components in relation to their conditions of use. This may lead to improved utilisation of the service lives, components of the same type with a similar state of wear being used to process a batch.
[0012] For this purpose, when components are exchanged, the quality of the component used for the exchange can rapidly be checked and compared using operating data and consequently a more reliable statement can be made about the usability thereof. Moreover, a categorisation of the components as a function of wear is made possible so the stock keeping becomes more transparent. Possible categories are above all the actual period of use of the components or the throughput achieved.
[0013] In addition, on the basis of knowledge of the wear of the stored components, it can be weighed up whether and to what extent the relevant components are used again or what quality can be achieved through the processing of a batch on the basis of the use of the components on a textile machine.
[0014] Above all, the operating data of the exchangeable components directly connected with the material to be processed, such as the fiber band (commonly referred to as a sliver) or the yarn to be produced, are to be recorded. According to the invention, the method is used in various textile machines, such as rotor spinning machines, ring spinning machines, winding machines, twisting machines or the like, in which the exchangeable components, in particular, are provided with transponders, which directly come into contact with the material to be processed and are therefore subject to greater wear than, for example, other exchangeable components of the textile machine.
[0015] A further substantial advantage is produced in that the operating data recorded in the transponder are not deleted when the exchangeable components are removed from the textile machine. The operating data recorded in the transponders are also available for a repeated use of the exchangeable components as the operating data were stored individually in the transponder associated with the respective component and not at a central location of the textile machine. In this manner, the necessary storage requirement at the textile machine is reduced. In addition, the textile machines do not have to be connected to one another in such a way for this that they can exchange operating data with one another to ensure that when using the component on a different textile machine of the same type, the history of the lifecycle of the exchanged component is available. Rather, the operating data of the components recorded in the transponders can be retrieved at any time and can be used to assess the state of wear.
[0016] In particular, the operating data relevant to the exchangeable component can be transferred automatically to the transponder for recording in the event of a work interruption. This may be the case, for example, on the initiation of a bobbin change, or a batch change or when there is a yarn break or a clearer cut or after the textile machine has been switched on. This achieves gap-free recording of the operating data over the lifecycle of the exchangeable components.
[0017] Advantageously, the operating data stored in the transponder may be automatically read out on introduction of the components into the workstations of the textile machine. Thus, the servicing personnel have available the data of the respective components which are installed in the textile machine as a replacement for other components. The data may be displayed for this purpose, for example directly at the respective workstation or at a central control unit.
[0018] Alternatively, the operating data stored in the transponders of the exchangeable components may be read out independently of their use in the workstations of the textile machine. This is, in particular, advantageous when storing the exchangeable components as the operating data recorded in the transponders can be retrieved at any time in order to be able to categorise the components according to their state of wear or to already be able to select them prior to their installation in the workstation of the textile machine.
[0019] For this purpose, the transponder may be read out and written by means of a transceiver. Furthermore, the operating data stored in the transponder may be encoded. In this manner, undesired reading or over-writing of the operating data stored in the transponders may be prevented.
[0020] According to the improved textile machine of the present invention, it is proposed that a sensor device for writing and reading the transponders attached to the components or integrated into the components should be arranged in the region of each workstation. In this manner, the operating data already recorded on the transponder are read out when the components are introduced into the respective workstation of the textile machine or the operating data are updated in the already installed position of the components after each completed work cycle to continuously document the lifecycle of the components. When the components are put into operation for the first time, these are initialised, in other words, the time of putting into operation is stored on the transponder of the components.
[0021] Advantageously, the workstations may in each case have a control device which is connected to the transceivers. Furthermore, the textile machine may have a central unit which is connected to the transceivers. Thus, the operating data are transmitted by the superordinate central control unit or by the workstations' own control devices to the transceivers and vice versa. For this purpose, the transmission of the operating data may be initiated, for example, by work interruptions, which are communicated by the respective control device of the workstations or the central control unit to the transceivers. In addition, at regular time intervals, a communication of the operating data may be initiated to update the database on the transponders of the exchangeable components used in the textile machine.
[0022] The transponder may be both an active and a passive transponder. The use of an active or passive transponder depends inter alia on the service life to be expected of the component and on the required transmission range of the operating data stored on the transponder. Active transponders are equipped with their own energy supply and therefore have a higher range than passive transponders. On the other hand, passive transponders are more economical.
[0023] The transceivers are preferably configured in such a way that the operating data of a plurality of components can be read out simultaneously. This is, in particular, advantageous if, for example, an assessment of components in stock is to be carried out as this process can be considerably accelerated thereby.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Further details of the invention can be inferred below from an embodiment shown in the drawings, in which:
[0025] FIG. 1 shows a side view of a workstation of an open-end rotor spinning machine;
[0026] FIG. 2 schematically shows the activation of the individual drives of a workstation in a further embodiment of the open-end rotor spinning machine;
[0027] FIG. 3 shows a schematic view of a spinning rotor;
[0028] FIG. 4 shows a schematic view of a support disc;
[0029] FIG. 5 shows a perspective view of a draw-off nozzle and a channel plate and a channel plate adapter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] FIG. 1 shows one half, i.e., one side, of a semi-automatic open-end rotor spinning machine 1 . Such spinning machines have a plurality of workstations 2 , which are in each case equipped with a spinning mechanism 3 and a winding device 33 . In the spinning mechanisms 3 , the fiber band 34 fed in spinning cans 28 is spun in each case to form a yarn 30 which is wound on the winding device 33 to form a cross-wound bobbin 22 . The winding devices 33 in this case have, as known per se, a respective creel 21 for the rotatable holding of the tube of a cross-wound bobbin 22 , a winding drive roller 23 , a yarn traversing device 26 and a device 7 for lifting the cross-wound bobbin 22 from the bobbin drive roller 23 .
[0031] The device 7 is, for example, configured as a thrust piston gear which is connected via a pneumatic line 24 , into which an electromagnetic valve 17 is connected, to an excess pressure source (not shown).
[0032] In the present embodiment, the drive of the bobbin drive roller 23 is implemented as a group drive. In other words, a drive shaft along the length of the machine is provided, to which the individual bobbin drive rollers 23 are fixed. In an alternative embodiment, however, a single motor drive of the bobbin drive roller 23 is also possible. In a case such as this, the drive of the bobbin drive roller 23 is connected by a corresponding control line to the spinning station's own control device 9 .
[0033] In the region of the winding device 33 , a yarn lifting device (not shown), known per se, may also be installed. A yarn lifting device of this type prevents the yarn unintentionally being able to be captured during the piecing process by the traversing yarn traversing device 26 . In other words, the yarn lifting device configured, for example, as a foldable plate firstly holds the yarn 30 during the actual piecing process at a spacing above the yarn traversing device 26 moving back and forth.
[0034] The spinning mechanism 3 substantially, as known, has a spinning rotor 4 , a fiber band opening roller 12 and a fiber band draw-in cylinder 14 .
[0035] According to the embodiment of FIG. 1 , the spinning rotor 4 is, for example, mounted in a support disc bearing 5 and is driven by a tangential belt 6 along the length of the machine.
[0036] To record the rotational speed of the spinning rotor 4 , a sensor device 8 may also be provided which is then connected via a signal line 40 to the control device 9 . The fiber band opening roller 12 is preferably also acted upon via a tangential belt 13 along the length of the machine, while the fiber band draw-in cylinder 14 is driven by a single motor via a drive 15 .
[0037] The drive of the fiber band draw-in cylinder 14 , for example a stepping motor 15 is also connected to the control device 9 via a control line 16 . Furthermore, the workstations 2 in each case have a yarn draw-off device 18 , the drive 19 of which is connected to the control device 9 via a control line 20 .
[0038] Arranged in the region of the workstation 2 is a transceiver 38 , which allows the contactless reading out and writing of transponders 37 which are arranged on the exchangeable components of the workstation 2 or are integrated in them, as shown in FIG. 3 with the aid of the spinning rotor 4 . The transceiver 38 is connected to the spinning station's own control device 9 via a control line 39 .
[0039] In an alternative embodiment, which is shown in FIG. 2 , the spinning rotor 4 is not supported in a support disc bearing 5 , but in a magnetic bearing indicated only schematically. The spinning rotor 4 is preferably acted upon in a case such as this by a single drive 31 .
[0040] The spinning rotor drive 31 is in this case connected to the control device 9 via a control line 45 . As further shown in the embodiment according to FIG. 2 , the fiber band opening roller 12 may also be driven by a single motor. In other words arranged inside the clothing ring of the fiber band opening roller 12 is, for example, an external rotor drive 59 which is also connected to the control device 9 via a control line 32 .
[0041] An exchangeable component of the workstation 2 , the spinning rotor 4 can be inferred from the view of FIG. 3 . The spinning rotor 4 is provided on the outside of the spinning cup 35 with a passive transponder 37 . Alternatively, active transponders can also be used; in other words, the transponders have their own current supply mechanism. This influences the range within which the data can be received and transmitted by the transponder.
[0042] FIGS. 4 and 5 show further exchangeable components of an open-end rotor spinning machine, such as a support disc 58 , a draw-off nozzle 56 , a channel plate 55 and a channel plate adapter 56 which are in each case equipped with a transponder 37 for recording operating data.
[0043] The method according to the invention is described in more detail with the aid of the exchange of the spinning rotor 4 . If a new, previously unused spinning rotor 4 is used in a workstation 2 , the transponder 37 arranged on the spinning rotor cup 35 is detected upon supply to the workstation 2 by the transceiver 38 , which leads to an activation of the transponder 37 . The operating data stored at this time in the transponder 37 are read out and passed to the control device 9 . The operating data are details about the previous period of use, use conditions such as rotor speed, throughput, number of yarn breaks and the like, in particular operating data which are suitable to characterise the behaviour of the spinning rotor as a function of the degree of wear.
[0044] Since, as already mentioned this involves an unused spinning rotor 4 , the lifecycle of which begins with its first use in the workstation 2 , first of all the time at which the spinning rotor 4 is first put into operation is stored on the transponder 37 . The operating data required for this are passed from the control device 9 to the transceiver 38 of the relevant workstation 2 . All the operating data which directly relate to the spinning rotor 4 and determine its wear behaviour, are now recorded when the spinning rotor is put into operation. The providing of these operating data likewise takes place by means of the control device 9 . The operating data to be recorded are for example batch data, in particular the fiber material use and the quantity of fiber band processed which was supplied to the spinning rotor 4 during its use on this open-end rotor spinning machine 1 . Thus, at any time, the throughput of the batch processed last or the total throughput of the spinning rotor 4 can be determined.
[0045] Furthermore, for example, the rotational speeds of the spinning rotor 4 recorded by the sensor device 8 or the rotational speed adjusted at the control device 9 are passed to the transceiver 38 and transmitted to the transponder 37 . Furthermore, the number of yarn breaks at the workstation 2 is recorded and transmitted to the transponder 37 .
[0046] This flow of information is maintained over the entire residence time of the spinning rotor 4 in the workstation 2 . In the process, the operating data to be recorded are constantly updated on the occurrence of a work interruption, for example at the beginning of a bobbin change to ensure gap-free recording of the operating data of the spinning rotor 4 .
[0047] When a change of the spinning rotor 4 is required, for example because of a batch change, the operating data stored in the transponder 37 are retained. If at a later point in time, the same spinning rotor 4 is installed in another open-end rotor spinning machine, the operating data of the spinning rotor 4 recorded and stored over the previous lifecycle are read out as already written at this textile machine and are available for evaluation of the state of wear independently of the previous use of the spinning rotor 4 .
[0048] For this purpose, the operating data stored in the transponders 37 of the exchangeable components can be read out independently of their use in the workstations 2 of the textile machine 1 . Reading out can take place by means of a hand device or the like so as to be able to categorise components to be exchanged before their use in the workstations 2 .
[0049] The method according to the invention can also be correspondingly used, for example, for the fiber band opening roller 12 , the support disc 58 , the draw-off nozzle 56 , the channel plate 55 or the channel plate adapter 57 of the open-end rotor spinning machine. | An improved method for operating a textile machine having plural workstations comprising exchangeable components, each having a readable and writable transponder arranged on or integrated in the exchangeable components. During the lifecycle of the exchangeable components at least the operating data which influence the wearing of the exchangeable components are automatically stored on the respective transponder. Textile machines for carrying out the method are characterised by arranging in the region of each workstation at least one transceiver for writing and reading the transponders attached to or integrated in the exchangeable components. | 3 |
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/615,545 filed Sep. 30, 2004, the entire teachings of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] In the flooring industry, carpet is typically installed from 12-foot wide rolls or in one foot square carpet “tiles”. The carpet material is glued and/or tacked to the subfloor. It is a laborious task to remove such installed carpeting. There are limited tools for assisting with carpet removal, especially for homeowner use in the residential setting.
[0003] There is a motorized tool/machine for removing carpet tiles and other tiles in an industrial setting by National Flooring Equipment of Minneapolis, Mo. Further National Flooring Equipment provides an industrial carpet lifting or pulling machine that utilizes a ¾ horsepower electric motor.
[0004] Other carpet removal tools are not automated or motorized such as in U.S. Pat. No. 5,505,433 to Carmichael et al.
SUMMARY OF THE INVENTION
[0005] Thus there is a need for a carpet removing or stripping machine that improves over the prior art.
[0006] The present invention provides a system and method that addresses the needs and problems of the prior art. The present invention provides a motorized mechanism for lifting or peeling carpet off the glued surface resulting in carpet removal. In a preferred embodiment, the present invention includes a dolly member carrying an electric winch and having a plurality of teeth protruding from a back surface of the dolly member for anchoring or stabilizing the invention machine in place during operation. A dual purpose safety screen serves as a cover over the teeth during transportation of the invention machine, and during operation of the invention machine, the safety screen shields the user from potential airborne debris.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0008] FIG. 1 is perspective view of a preferred embodiment of the present invention in transportation mode.
[0009] FIGS. 2 and 3 are perspective views of the embodiment of FIG. 1 but in use or operational mode and including a pull bar.
[0010] FIG. 4 is a perspective view of the pull bar in the embodiment of FIGS. 2 and 3 .
[0011] FIG. 5 is a side view of the pull bar of FIG. 4 .
[0012] FIG. 6 is a bottom perspective view of the embodiment of FIGS. 2 and 3 .
[0013] FIG. 7 is a partial view of Fib. 6 at the circled inset.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Illustrated in FIGS. 1-3 is one embodiment of the present invention. Generally the illustrated machine 10 is formed of a main dolly-like member 11 , a motorized winching system 21 , and a safety shield 31 that has a dual purpose. Each of these components or subsystems is described in more detail below.
[0015] The main dolly-like member 11 has a one foot wide main body (frame) with a handle proximal end 13 opposite a distal foot end 15 . Between the proximal 13 and distal 15 ends are front face (side) 17 and opposite back face (side) 19 of the main body/frame. Wheels 23 are attached to the foot end 15 of the main body enabling the invention machine 10 to be mobile (movable under user control). Two prongs 25 protrude from main body front face 17 at the foot end 15 .
[0016] In a preferred embodiment dolly member 11 (including main body, prongs 25 and wheels 23 ) is a Magliner aluminum dolly with two 8 inch wheels. Other dollies or similar assemblies with common dimensions may be used.
[0017] Coupled to the front side 17 between prongs 25 is a motorized winching system 21 . In a preferred embodiment, the winching system 21 includes a Dayton 2K pound capacity electric winch 29 with a 5/16 inch diameter aircraft (steel) or similar material cable 33 as shown in FIGS. 2 and 3 . The electric powered winch 29 is bolted to a steel plate 27 that is fixed to the front side 17 of the dolly member 11 . Steel plate 27 is preferably ¼ inch thick and about 1 foot wide by 15 inches long. Other dimensions for steel plate 27 are suitable.
[0018] Cable 33 of the winching system 21 is about 20 feet long or longer in the preferred embodiment. One end of the cable 33 is connected to the winch pulling or take-up mechanism while the opposite end is connected to a clasping hook 39 or similar connector. The clasping hook 39 is either threaded through or removably coupled to an appropriate loop 35 of pull bar 37 ( FIG. 3 ).
[0019] In a preferred embodiment shown in FIGS. 4 and 5 , pull bar 37 is formed of a 1¾ inch thick U-shaped piece of steel 41 with two plates 43 of 1½ inch square stock fitted into the opening of the U-shape. Two or more C clamps 45 (or other clamps) are welded to the U-shaped steel piece 41 and spaced apart along the length of the pull bar 37 . A carpet edge 55 ( FIG. 3 ) is insertable into the opening of the U-shape and clamped between the plates 43 upon tightening of the C clamps 45 . Pull bar 37 may be of various lengths. Applicant prefers the use of a 2 foot long pull bar 37 for doorway and other relatively narrow areas and a 4 foot long pull bar 37 for other areas of use.
[0020] Referring back to FIG. 3 , the back side 19 of the dolly member 11 is lined with a ¼ inch thick steel plate 47 (about 1 foot wide by 44 inches long in the preferred embodiment). Steel liner plate 47 is bolted or otherwise fixed to the dolly 11 frame. As illustrated in FIGS. 6 and 7 , framing plates with a plurality of ¾ inch long or longer teeth 49 are fixedly attached to the steel liner plate 47 such that the teeth 49 protrude out and away from the back side 19 of dolly member 11 . In a preferred embodiment, the invention machine 10 has over 3000 such teeth 49 . In contrast, the carpet pulling tools in the prior art have about ⅓ or fewer number of teeth and smaller sized teeth which have proven not to grip well so that the prior art machines tend to slide during operation which poses a safety hazard and a performance loss.
[0021] During storage (times of non-use) and transportation of the invention machine 10 , safety shield 31 serves as a protective cover over teeth 49 as shown in FIG. 1 . This protects the user from the sharp teeth 49 as well as protects truck surfaces or other exposed surfaces from being scratched or gouged by the teeth 49 . Safety shield 31 is a framed 1 foot by 5 foot metal screen removably bolted to the dolly frame. For example, in one embodiment, two wing nut bolts 51 ( FIG. 1 ) hold safety shield 31 onto the back side 19 of the dolly member 11 .
[0022] Thus during transportation and upon arrival at the desired site for use of the invention machine 10 , safety shield 31 is in teeth 49 covering position as shown in FIG. 1 . The invention machine 10 is safely and easily handled and maneuvered just like a typical dolly. The invention machine 10 being only about 1 foot wide overall (the width of main dolly member 11 ) easily fits through doorways and passages in a house setting, for example (as opposed to industrial/commercial settings in the prior art).
[0023] Once the user has wheeled the invention machine 10 to the desired location for carpet removal, the safety shield 31 is removed from the dolly member back side 19 and removably attached (i.e., bolted) on end to the dolly prongs 25 . See FIGS. 2, 3 and 6 . The invention machine 10 is placed in operating position by laying the dolly member back 19 and teeth 49 side down on the carpet (the safety shield 31 no longer covering the teeth). The teeth 49 under the weight of the invention machine 10 have an anchoring effect and stabilize (make stationary) the invention machine 10 during operation.
[0024] The winch cable 33 is uncoiled and the clasping hook end 39 is either strung through or removably attached to a loop 35 of a desired pull bar 37 . If the clasping hook 39 is strung through loop 35 then the cable 33 is doubled back to the winch unit 29 where the clasping hook 39 is secured (connected) appropriately. An exposed edge 55 of the subject carpet 57 is placed into the opening of the pull bar 37 and the pull bar 37 is made to securely grip the carpet edge 55 as previously described in FIGS. 4 and 5 . Once the pull bar 37 is secured onto the subject carpet edge 55 , the user can operate the winch 29 to pull the pull bar 37 and thus pull (or peel) the carpet 57 off the subfloor toward the anchored invention machine 10 . During this operation, the user stands behind the safety shield 31 now in its user screening position. In this mode, the safety shield 31 provides an effective area of protection for the user to stand in. The effective area of protection is about 1 foot wide by 5 feet high, which is an improvement over the prior art dimensions for safety shielding. The safety shield 31 being of screen material allows the user to view the carpet pulling activity (of the winch 29 and pull bar 37 ) while being shielded from any airborne debris. Where the cable 33 is of a material that will not stretch or bind, there is reduced danger of any snap back should the cable break. Further, the cable 33 in the preferred embodiment is of material proven to unlikely break. The safety shield 31 provides added protection in the event of the cable breaking during operation of the invention machine 10 . Such is not the case in the prior art tools.
[0025] Accordingly, the present invention provides a relatively light weight motorized carpet removal machine 10 usable especially by the homeowner or in the residential setting. A safety shield 31 duals as a cover to the teeth side 49 of the invention machine 10 and a safety screen for the user to stand behind during operation of the invention machine 10 . Such a carpet removal machine has heretofore been unachieved by the prior art.
[0026] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
[0027] For example, the foregoing description includes various dimensions for purposes of illustration and not limitation of the present invention. Similarly, material of the various parts is specified for purposes of illustration and not limitation of the present invention.
[0028] In another example, the electric winch 29 may be remotely controlled and/or powered by a battery pack as opposed to AC current. Other motorized winches and power sources for the same are suitable.
[0029] Where bolts and hooks are mentioned, it is understood that other fasteners and connectors are suitable and in the purview of one skilled in the art given this disclosure. | A carpet removal or stripping method and system (machine) employs a common dolly. The backside of the dolly member has a plurality of teeth. A motorized winching system is coupled to the front side of the dolly member. A dual purpose safety shield covers the teeth during transportation and serves as a protective screen for the user during carpet removal operation of the invention machine. The winching system automates carpet peeling activity with the dolly member lying backside down during operation, and the teeth provide an anchoring effect. A pull bar removably grasps the subject carpet. A cable is coupled between the winching system and the pull bar. The winching system takes up or pulls the cable and hence the pull bar, such that the carpet is peeled away and separated from the subfloor. | 4 |
BRIEF DESCRIPTION OF THE INVENTION
The process for the removal of petroleum residues of relatively high viscosity from pits and ponds by floating an Archimedean screw-type pump in the pit or pond such that its inlet is proximate of the surface of the pit or pond, providing a thermal gradient about the pump such that less viscous components of the petroleum residues become more highly concentrated in the vicinity of the inlet to the pump, utilizing a positive pressure on a surface layer of the residues in the pit or pond such that a flow of petroleum residue is created toward the inlet to the pump and a petroleum residue composition of a lower viscosity than that of the remainder of the pit or pond is displaced to the inlet of the pump and the displaced residue is pumped from the pit or pond to a shore facility.
BACKGROUND TO THE INVENTION
Throughout the world there are deposits of petroleum residues that are created artificially or naturally. For example, Bahrain pitch derives from the black oil residues of the Caltex Petroleum Corporation refinery [now operated by the affiliated Bahrain Petroleum Company B.S.C. (closed)] located in Sitrah, Bahrain (the largest island of the Bahrain group of islands), generated in the 1938-1942 time period. The residue, apparently with brackish quench water, was deposited in this time period in seven (7) pits creating seven (7) pitch ponds having a total area of about 70,000 square meters. The only changes to this resting body of pitch over the years since 1942 are those gently wrought by natural forces, such as the dusting over by desert sands, evaporation from the searing Asia Minor (Middle East) heat and deposition of rain water and migrated sea water. The black oil residues deposited in the pits were compositionally relatively consistent because they were made primarily over a short period of time while the refinery was being limited to the manufacture of aviation fuel and other "light" cracked hydrocarbon feedstocks. Variability in the pitch was inputted when, during that period, untreated crude oil was fed through the refinery and then deposited into the pits. Thus, "Bahrain pitch", as that term is employed herein and in the claims, means the pitch collected and located in the aforementioned seven (7) ponds, as it was generated in the W.W.II timeframe and modified by natural forces in subsequent years to the year 1987. Its unique past establishes the pitch to be an unique material.
Essentially all of the other black oil residues deposits about the world are "newly" created relative to the creation of the Bahrain pitch ponds. Hardly any of them are more than 30 years old and most of them were formed from residues of a highly diverse nature reflecting the advances in petroleum technology in the years between the formation of Bahrain pitch and this more recent period. Consequently, they possess compositions materially different from Bahrain pitch. The differences in chemical composition of Bahrain pitch from other black oil residue deposits can be seen from the differences in physical properties of Bahrain pitch and the other black oil residue deposits. One factor that stands out about Bahrain pitch is its high viscosity. In this regard, Bahrain pitch's viscosity fits somewhere between conventional residue deposits and the naturally occurring bitumens used primarily for making asphalt. This high viscosity is a reflection of the pitch's unusually high paraffinic and crystalline wax contents and its high asphaltenes content. Most of the world's black oil residues contain individually no more than about 10 weight % of these materials whereas Bahrain pitch contains more than about 20 weight % of them. In addition to this high wax and asphaltenes content, Bahrain pitch has an inordinately high crystallized carbon content.
The special black oil residues used in forming the Bahrain pitch coupled with the environmental considerations extant during the history of the ponds caused to be generated a unique composition of matter. The quiescent state of its existence allowed the Bahrain pitch to undergo a transformation not unlike that which occurred in naturally-occurring asphaltic bitumens that one finds in countries such as Venezuela and Trinidad. Of course, the limited age of the Bahrain pitch ponds precludes the pitch from reaching the ripe physical state of these other natural bodies. Even so, aromatic molecules within the pitch benefited from the extended quiescent condition to become aligned into large anisotropic bodies which contribute to the pitch's high viscosity. Though such transformation is interesting chemistry, it however transformed Bahrain pitch from a material which theoretically could have been readily exploited for its fuel value. To date, very little of the Bahrain pitch ponds has been mined for any purpose whatsoever and none of that has been for an effective commercial gain.
Unrefined Bahrain pitch has a high viscosity in the range of greater than 40,000 centistokes, as determined at 150° F. (65.6° C.), greater than 6,000 centistokes, as determined at 125° F. (79° C.) and 2-5,000 centistokes, as determined at 200° F. (93° C.) Its A.P.I. at 60° F. (15.5° C.) is less than 0, calculated to be typically -6 to -10 A.P.I.
Unrefined Bahrain pitch comprises as major constituents,
2 to 10 weight percent of total sediments including siliceous particulate matter and carbon particulate matter (generally viewed as crystallized colloidal carbon),
8 to 12 weight percent of paraffinic and microcrystalline waxes, and
20 to 25 weight percent of asphaltenes.
The following table sets forth a summary of the composition and known properties of the Bahrain pitch:
TABLE 1______________________________________Typical Specifications from Bahrain Pitch Ponds Neat Pitch 5%.sup.* 10%.sup.** 15%.sup.***______________________________________Viscosities @ 38° C.Centistokes >20,000 11,000 1,500 900Redwood (sec.s) 95,000 52,250 7,125 4,275Saybolt (sec.s) 85,000 46,750 6,375 3,825Ash Content, w/w max. 0.1 0.1 0.1 0.1BS & W, % w/w max. 1 1 1 1Sulphur Content, % w/w 4.9 4.7 4.4 4.2Flash Point °C. 129 61 61 61Pour Point °C. 42. 29.3 27.1 15.0°F. 107.6 86. 81. 59.Asphaltenes, % w/w 24 23 22 20______________________________________ .sup.* Diluted by that weight % by diesel or light cycle gas oil. .sup.** Diluted by that weight % by diesel or light cycle gas oil. .sup.*** Diluted by that weight % by diesel or light cycle gas oil.
It has been known for some time that the practical limit for cutting unrefined Bahrain pitch with light cycle gas oil or diesel oil is 15-18% w/w. Above this figure precipitation of asphaltenes from solution was recognized as occurring.
The Bahrain pitch as found in the ponds has a significant particulates sediment content ranging in the area of 2 to 10 weight %, give or take a percent, based on the weight of the pitch. Of this sediment content, the inorganic oxide content of the sediment ranges in the area of 0.25 to 5% by weight of the pitch. The inorganic oxide content should be reduced in refining the pitch to the first stage, to between 0.05 to 0.1% by weight of the pitch, and preferably a lesser amount. The remainder of the sediment content of the pitch is particulate carbon matter, such as crystallized colloidal carbon.
According to Nelson, Petroleum Refinery Engineering, Fourth Edition, McGraw-Hill Book Company, New York, N.Y., London, at pages 71-72,
"At gravities below 10 API, water and sediment do not settle out of the oil and such oils cannot be displaced from tanks by water."
The properties reflected above with respect to the black oil residues of Bahrain and the residues deposited from refineries elsewhere are more tractable than the naturally-occurring asphaltic bitumens that one finds in countries such as Venezuela (Orinoco basin) and Trinidad. However, in all instances, these highly viscous residues and asphalt containing materials possess substantial viscosities and are of a generally intractable nature.
The most common method employed for the removal of these viscous materials from their landfill deposits has been by shovel, typically mechanically but sometimes by hand. Some efforts have been made to use archimedean screw-type pumps to more continuously remove them from the landfill deposits. None of these procedures have proven totally adequate for an effectively commercial process for recovering such residues and asphaltic materials from the deposits. The exceptionally high viscosities of these materials makes these procedures slow and irregular, thereby materially increasing the cost of the recovery efforts.
There is need in the industrial recovery of petroleum residue and asphalt deposits for a more efficient and effective method for removing the deposits for subsequent treatment. This invention relates to a process and an apparatus sequence that materially enhances ones ability to effect such recovery.
THE INVENTION
This invention stems from the recognition that the petroleum residue deposits as well as asphalt deposits, the world over, possess at least a small amount of less viscous components which if more concentrated in the deposits would aid at selected temperatures in significantly reducing the viscosity of the deposits such that their recovery can be made materially easier to carry out. As indicated above, it is well known that the viscosities of such deposits can be materially reduced by blending a solvent in the deposits. However, such solvents have a materially greater money value than the deposits. As a result, their use greatly increases the cost of the recovered deposit materials and since the deposits possess relatively low commercial value, the use of solvents becomes economically prohibitive. This invention utilizes inherently-present solvents in the residues and asphalts to aid in the reduction of the viscosity of the deposit materials whereby to enhance their recovery for further processing.
The invention relates to the recovery of materials from viscous bodies of petroleum residue and asphalt deposits which contain substantial quantities of the deposits. The invention is concerned with the recovery of viscous petroleum residue and asphalt deposits from pits or ponds of substantial size from which recovery of the deposits are normally difficult to effect. Though the invention is directed primarily to the recovery of petroleum residue and asphalt deposits having gravities below 10 A.P.I. that are located in fairly large and/or deep pits and ponds, it is also applicable to the recovery of other petroleum materials having a higher A.P.I. gravity that are difficult to recovery such as petroleum residues containing high paraffinic or microcrystalline wax contents.
This invention relates to a process which comprises a combination of features which include
i. providing a thermal gradient in the region of the surface of a viscous body of petroleum residue or asphalt deposit,
ii. locating an archimedean screw-type pump in said region such that the inlet of the pump is proximate of the surface of the deposit and the outlet of the pump is openly connected to transport means for passing the deposit from the pump to a shore receiving system used for the recovery of the deposit,
iii. passing a skimmer in a reciprocating motion relative to the pump such that deposit is pushed by the skimmer toward the pump within said region and then withdrawn from the pump in a direction away from the pump, and iv. transporting deposit into the inlet of the pump, through the outlet of the pump and to said shore receiving system.
Preferably, the process of the invention relates to the removal of petroleum residues of relatively high viscosity from pits and ponds by floating an archimedean screw-type pump in the pit or pond such that its inlet is proximate of the surface of the pit or pond, providing a thermal gradient about the pump such that less viscous components of the petroleum residues become more highly concentrated in the vicinity of the inlet to the pump, utilizing a positive pressure on a surface layer of the residues in the pit or pond such that a flow of petroleum residue is created toward the inlet to the pump and a petroleum residue composition of a lower viscosity than that of the remainder of the pit or pond is displaced to the inlet of the pump and the displaced residue is pumped from the pit or pond to a shore facility.
The invention relates to an apparatus for the removal of petroleum residues of relatively high viscosity from pits and ponds which comprises a floating archimedean screw-type pump in the pit or pond such that its inlet is proximate of the surface of the pit or pond, means for providing a thermal gradient about the pump such that less viscous components of the petroleum residues become more highly concentrated in the vicinity of the inlet to the pump, means for applying a positive pressure on a surface layer of the residues in the pit or pond such that a flow of petroleum residue is created toward the inlet to the pump and a petroleum residue composition of a lower viscosity than that of the remainder of the pit or pond is displaced to the inlet of the pump such that the displaced residue is pumped from the pit or pond to a shore facility.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic top view of a pitch pond or pit containing an apparatus assembly including the apparatus of the invention, suitable for carrying out the process of the invention.
FIG. 2 is a side view showing a cross-sectional view of the pond or pit illustrating the relative arrangement of the equipment characterized in FIG. 1.
FIG. 3 is a three quarter perspective view of a skimmer or blade assembly in action in the pond or pit serving to move the pond or pit deposits to the removal pump.
FIG. 4 is a perspective view of a steam sparging device with a phantom illustration of the pump and skimmer.
FIG. 5 is a cross-sectional view of a general characterization of the principles of the process of the invention.
FIG. 6 is perspective view of the pump, partially shown in a cross-sectional view, and FIG. 8 is a perspective blow-up of the inlet containing a sparge ring.
FIG. 7 is perspective view of the pump, partially shown in a cross-sectional view, and FIG. 9 is a perspective blow-up of the inlet containing a sparge ring, plus an adjustable inlet hopper with a piston arrangement for raising, lowering and directing the hopper.
DETAILED DESCRIPTION OF THE INVENTION
All petroleum residues and asphalts contain a molecular distribution that varies significantly. As a general rule, the lower the molecular weight of a component in the petroleum residue or asphaltic compositions, the less viscous will be the component. The less viscous components may not be significantly lower boiling than the less volatile components of the petroleum residue or asphaltic compositions, but when concentrated, they are clearly less viscous and more flowable at lower temperatures.
It has been discovered that thermal treatment of petroleum residues and asphalts causes the less viscous components of those compositions to rise and sufficiently separate from the more viscous components of the compositions such that there is caused a gradient reduction in viscosity in the compositions. This invention takes advantage of that phenomena and lowers the viscosity of the compositions in a manner that facilitates their removal from pits and ponds.
The invention utilizes localized introduction of heat to a large body of deposited petroleum residues or asphalt such that the temperature in a predominant portion of the body is unaffected by such localized introduction of heat. However, the invention utilizes localized heating to alter the composition of the residue or asphalt in the proximity of the heating and to cause less viscous residue or asphalt composition to migrate into the localized heated region. This sequence causes the process to be continuous in the sense that the solvation of the deposit, which is subject to removal through an archimedean screw-like pump, is effected by a extracting a higher concentration of the less viscous components from other portions of the body being treated.
The invention incorporates localized heating of a relatively large body of viscous petroleum residues or asphalt deposit so as to cause seepage of less viscous components of the deposit to the area of the localized heating such that the concentration of the less viscous components in such area is increased and the flow characteristics of the deposit in the area of localized heating is improved, i.e., the deposit exhibits a less viscous nature.
The drawings illustrate one particular mode for practicing the invention. Other modes are contemplated and the invention is not intended to be limited to that depicted in the drawings.
With respect to FIGS. 1 and 2, there is shown pond or pit area 1 contained by land mass 2. Pond or pit 1 may contain a viscous body of petroleum residues deposit or an asphalt deposit (natural or synthetic). Located offshore in area 1 is archimedean screw-like pump 3 suspended in the viscous body by floatation devices 5. Surrounding an area about pump 3 within area 1 is thermal transfer line or lines 29, supplied with heat from an offshore system (not shown). As shown in FIGS. 1 and 2, line 29 comprises a loop arrangement about pump 3 to insure the localization of heat in the vicinity of pump 3. The arrows in line 29 characterize the flow within the line.
Line 29 may be an electrically or fluid heated pipe or a system that effects heating of the deposit residing about it by contact heating. Illustrative of the following is a porous piping in which heated steam fed from land is caused to bubble from orifices in the piping into the surrounding deposit and by contact heating, raises the temperature of the deposit. This induces a thermal gradient about line 29 and also about pump 3.
It has been determined that if one were to rely solely on the induced temperature gradient in the localized regions of a pit or pond to effect removal of the deposit, there would be insufficient flow into the pump to efficiently support the pumping action. In order to induce sufficient of the very viscous deposit to the induction end of the pump, inlet 6, it is desirable to introduce a positive pressure on a thermally treated portion of the deposit so that a mass thereof is transported to the inlet of the pump. This can be easily accomplished by positioning a blade or skimmer 7 in the localized heated region of the pit or pond 1 surrounding pump 3 and using travel guide cables 13 and 15, to which blade or skimmer 7 is affixed, in this case, through frame 17, to move the blade or skimmer 7 forward toward pump 3 while it cuts into the viscous body and forces deposit into the inlet 6 of pump 3. As shown in FIG. 2, blade or skimmer 7 is capable of pivoting in frame 17 such that on withdrawal from pump 3, after having forced a load of the deposit into the pump inlet 6, the blade or skimmer 7 is pushed out into hatched line position 9 on the surface of the viscous body. As a result, blade or skimmer 7 rides during withdrawal on the surface of the viscous body without introduction of significant resistance to movement. Frame 17 is affixed to flotation devices 11 which serve to keep frame 17 and blade or skimmer 7 in the desired positions relative to the viscous body of deposit materials.
The movement of blade or skimmer 7 is controlled by matched pulley systems 21 and 33. Their top and side views are depicted in FIGS. 1 and 2. Each pulley system is driven by its own motor, 25 and 31. The pulley systems are located on support surfaces 23 and 32 and each system, 21 or 33, rotates on a common axle for each pair of pulley wheels that are mounted in support walls 22 and 30 respectively. Of course, support walls are provided on opposite sides of the pair of pulley wheels.
As shown in FIGS. 1 and 2, the outlet of pump 3 is connected to withdrawal pipe 19 and the driving force for carrying the deposit is the pump 3 driven by motor 8. Motor 8 may be electrical or gasoline controlled. The removed deposit is collected in storage tank 27. In certain circumstances it may be desirable to heat withdrawal pipe 19 to facilitate the removal of the deposit via the pump and the withdrawal pipe. For example, should the viscosity of the deposit in pipe 19 increase when the pipe is outside of the heated region about pump 3, and the viscosity is too great for pump 3 to handle, then by raising the temperature of pipe 19, the viscosity of the deposit in pipe 19 can be sufficiently lowered to facilitate the removal operation. Such heating of pipe 19 can be effected by electrically heating the pipe by providing an electrical wrapping around pipe 19 at least in those sections of pipe 19 where sufficient "freezing" of deposit occurs that removal of the deposit is deleteriously inhibited.
FIG. 3 provides a more detailed characterization of the operation of blade or skimmer 7 as it cuts through viscous body 1 pushing deposit toward pump 3. As shown, blade or skimmer 7 cuts into the body 1 and forces a portion of the material forward to the pump. Frame 17 comprises a pivot axle 37 that extends the length of the frame. The axle 37 is a rod with threaded ends that allow the bolting of the axle to frame 17. Axle 37 extends through sleeve 36 which coexists at the other side of frame 17. Extending through sleeves 36 are cables 13 and 15, see FIGS. 1 and 2 above. Cables 13 and 15 are held in fixed positions by sleeves 36 so that as the cables move, so moves frame 17. Frame 17 securely holds blade or skimmer 7 by sliding axle 37 through a tubular end in blade or skimmer 7 so that blade or skimmer 7 can pivot or rotate on axle 37. Blade or skimmer 7 is held in the position shown in FIG. 3 by backwall 35 which forms part of frame 17. Backwall 35 acts as a stop for blade or skimmer 7 so that its rotation is a counterclockwise direction is arrested so that it is maintained in the vertical position shown in FIGS. 2 and 3. However, frame 17 is suitably constructed that blade or skimmer 7 can freely rotate in a clockwise direction when the blade or skimmer 7 is withdrawn from pump 7. Needless to say that whether blade or skimmer 7 rotates clockwise or counterclockwise when withdrawn from pump 3 is dependent on the positional relationship taken for these instruments.
In FIGS. 1 and 2, blade or skimmer 7 is positioned so that when it is pushed toward pump 3, blade or skimmer 7 is pushed in a counterclockwise direction. If blade or skimmer 7 were located on the other side of pump 3, then, of course, it would be pushed in a clockwise direction.
A desirable method for heating the region of pond or pit 1 around pump 3 is depicted in FIG. 4. As a replacement for line 29 as shown in FIGS. 1 and 2, one may employ tubular coil 38 according to the arrangement of FIG. 4. As shown in FIG. 4, coil 38 possesses a tubular inlet 39 and a tubular outlet 41. Located on each tubular leg of coil 38 are sparging holes 43, each of which openly connect with the interior of each of the tubular legs. The relationship of pump 3 containing inlet 6 and blade or skimmer 7 to tubular coil 38 is established by showing a phantom representation of pump 3 and blade or skimmer 7 in FIG. 4. The operation of coil 38 is simple. A heated fluid, preferably steam, is supplied through the tubular inlet 39 and issues through sparging holes 43 as it circulates through coil 38. Enough heated fluid is supplied to coil 38 that a portion remains to pass through outlet 41. Uniformity of the sparge streams that issue through and from sparging holes 43 can be controlled by correlating the diameters of the holes to the steam pressure in the various portions of coil 38.
The operation of the process of the invention is further demonstrated in the schematic representation depicted in FIG. 5. As shown in FIG. 5, there is located line 29 in a region below and around pump 3 containing inlet 6, whose entry port is positioned at about the surface of viscous body 1. In this embodiment, line 29 can be a variety of heating means but in this case, it is represented by coil 38 of FIG. 4. As steam issues from sparging holes 43 into the viscous body located about pump 3, steam represented by the wiggly lines courses upward and heats the region around pump 3. This causes a temperature gradient to be created from line 29 to the surface of body 1. This temperature gradient is illustrated by zones A, B and C, each illustrated as differently shaded rectangular zones. The deeper shaded zone A is located closest to line 29, therefore that zone is at a higher temperature than zones B and C. Logically, zone B is hotter than zone C. Because of this temperature differential, less viscous materials are concentrated to the greatest extent, on a relative basis, in the hottest zone, in this case zone A. Because line 29 is a loop that allows deposit to pass through it, less viscous components in the deposited material located below line 29 are caused to migrate upward to replace less viscous materials removed to a higher level in the viscous body. This also takes place outside the loop of line 29. Thus, heating of the body in a region causes striations of less viscous material to be eluted from sections of the viscous body into other sections of the viscous body. As a consequence of heating one section of the viscous body, less viscous materials are extracted upwardly in a larger region of the body extending outside of the heated region, all effected without having to heat the larger region.
As pointed out above, petroleum residues vary from site to site. In some cases, the residues are waxy and in some cases they are viscoelastic. In other cases, the residues contain sufficient byproduct chemicals that they have a sufficient low enough viscosity to allow reasonable flow under the recovery conditions described above. Therefore, there are situations where sparged steam might not adequately raise the temperature of the body 1 at the region about the pump to insure adequate deposit removal. In such a case, an alternative to the use of sparge ring is a closed loop heating coil which circumscribes the heating region about the pump. The coil would be heated by a suitably heated fluid brought to a temperature greater than 100° C. Suitable heated fluids comprise steam or commercially available heat transfer fluids.
However, in those cases where the residues are so waxy or visco-elastic that they tend to plug the inlet of the archimedean screw-like pump 3, there are simple alterations to the pump that can be made that will insure the easy introduction of the residue deposits to the blade of the pump without holdup at the hopper inlet 6 of the pump. One such alteration is shown in FIG. 6.
FIG. 6 shows an alteration of pump 3 which includes the use of a sparger ring 45 at the entrance of hopper inlet 6. Sparger ring 45 comprises a series of nozzles circumscribing the entrance of hopper 6. As a flow aid to deposit fed to the hopper entrance, as shown in FIG. 8, hot water or well-known chemical flow aid mixtures can be sprayed, shown as spray streams 47, from all or many of the nozzles into the interior of hopper inlet 6. This procedure facilitates the feeding to the blades of the pump when the deposit being fed is almost intractible and helps to reduce the drag coefficient on the hopper walls and product delivery pipe 19, see FIGS. 1 and 2.
FIG. 7 illustrates an improvement in the hopper inlet design which provides maximum adaptibility to flow and feed considerations. In this figure, the hopper inlet 49 is a modification of the hopper inlet 6 design of FIG. 6. As shown in FIG. 9, hopper inlet 49 comprises housing 48 and contains sparger ring 45 and spray streams 47 discussed previously. In addition, hopper housing 48 is circumscribed by four (4) hydraulically or pneumatically controlled pistons 51, three of which are shown in FIG. 9. The pistons 51 are affixed to hopper housing 48 by piston brackets 55 and to fixed collar 52 by brackets 53. Collar 52 is fixedly linked to the outer shell of pump 3. Each of the pistons 51 contain fluid tubings 54, for supplying fluid, air or liquid, to actuate or control the individual pistons. By virtue of separate controls over the operation of the pistons 51, hopper housing 48 can be raised or lowered uniformly or raised or lowered nonuniformly, i.e., eccentrically, at an one or more piston 51 sites. There is provided in hopper 49, internal sleeve 56 which is fixed to the shell of pump 3. The lower end of housing 48 is another sleeve that mates with sleeve 56 so that housing 48 can be slid up or down sleeve 56. By making sleeve 56 of a material that is flexible, such as rubber, pistons 51 can also operate to bend the hopper inlet in any direction, such as toward or away from the direction of deposit flow actuated by blade or skimmer 7.
The arrangement of FIGS. 7 and 9 works as follows. There are occasions when the surface of the pit or pond will vary during the recovery operation, mainly owing to the response of the viscous body 1 to either too little or too much delivery of deposit by the action of blade or skimmer 7. There will be times when the hopper inlet should be lowered or raised or turned into or away from the direction of deposit flow. All of these conditions can be readily accomodated by the novel hopper design for the pump, as depicted in FIGS. 7 and 9. | The recovery of materials from viscous bodies of petroleum residue and asphalt deposits which contain substantial quantities of the deposits by the use of an induced thermal gradient in a region of such a viscous body in which there is located a screw-like pump.
This is effected by a process and apparatus that utilizes a thermal gradient about a archimedian screw-type pump in the pit or pond where its inlet is proximate of the surface of the pit or pond. The thermal gradient about the pump concentrates less viscous components at the vicinity of the inlet and a positive pressure is applied to assure a flow of residue towards the inlet allowing the lower viscosity materials to be captured and pumped from the pit or pond to a shore facility. | 4 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a connector and, in particular, to a sleeve-type wire connector that can effectively facilitate smooth connection of wire connecting ends and ensure electrical conductivity thereof.
2. Related Art
Users often need to connect two wires in order to extend the reach. Normally, one uses a wire connector to connect two wires. However, the conventional wire connector, as shown in FIG. 4 , is basically a tube with two opposite openings integrally formed by a plastic injector. A body part 62 with a smaller diameter is formed between the two openings 61 . Afterwards, a copper sleeve 63 is then inserted into the body part 62 to form a wire connector.
However, the conventional wire connector has a roughly vertical ladder section 64 at the junction between the openings 61 and the inner surface of the copper sleeve 63 . The ladder section 64 is an obstacle for the core lines 66 of the wires 65 to insert. Therefore, the connection may not be sufficiently smooth. Moreover, for a wire 65 comprised of multiple core lines 66 , the outermost core lines 66 are likely bent by the ladder section 64 . This in the end affects the electrical power of the system.
Besides, it is more difficult for an injection molding machine to make both ends of the connector expand outward. The involved design is more complicated and costly. Also, due to the complication, the production yield cannot be effectively increased.
SUMMARY OF THE INVENTION
An objective of the invention is to provide a sleeve-type wire connector that has a lower production cost but can effectively increase the smoothness of wire connections. It can increase the work efficiency, as well as ensure the electrical conductivity of the wires.
To achieve the above objective, the disclosed sleeve-type wire connector comprises:
a first tube having a first opening end that expands outward and a connecting end, with the inner surface of the first opening end being disposed annularly with a first guiding surface that retracts toward the connecting end thereof and a first stopping surface being formed at the junction between the first guiding surface and the inner surface of the connecting end;
a copper sleeve disposed in the connecting end of the first tube and engaged with the first stopping surface of the first tube by its one end; and
a second tube having a mounting end corresponding to the connecting end of the first tube and a second opening end that expands outward, with the inner surface of the second opening end being disposed annularly with a second guiding surface that retracts toward the mounting end thereof and a second stopping surface being formed at the junction between the second guiding surface and the inner surface of the mounting end;
wherein the second stopping surface of the second tube urges against the other end of the copper sleeve when the mounting end of the second tube is mounted onto the connecting end of the first tube.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein:
FIG. 1 is a schematic view of the disclosed structure;
FIG. 2 is a schematic view of the invention after assembly;
FIG. 3 is a schematic view of the invention in use; and
FIG. 4 is a schematic view of a conventional wire connector in use.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
Please refer to FIGS. 1 and 2 that show a sleeve-type wire connector according to the invention. It mainly consists of a first tube 11 , a copper sleeve 21 , and a second tube 31 .
The first tube 11 is integrally formed by an injection molding machine to be a hollow pipe. Its one end is a first opening end 12 expanding outward, and its other end is a connecting end 13 in communication with the first opening end 12 . The inner surface of the first opening end 12 is provided with a first guiding surface 14 that gradually shrinks toward the connecting end 13 . A first stopping surface 15 is formed at the junction between the first guiding surface 14 and the inner surface of the connecting end 13 .
The copper sleeve 21 is also a hollow tube, mounted in the connecting end 13 of the first tube 11 . The outer surface of the copper sleeve 21 exactly attaches to the inner surface of the connecting end 13 of the first tube 11 . When the copper sleeve 21 is accommodated in the connecting end 13 of the first tube 11 , its one end urges against the first stopping surface 15 of the connecting end 13 of the first tube 11 .
The second tube 31 is also a hollow tube, integrally formed by an injection molding machine. One end of the second tube 31 is formed with a mounting end 32 that can correspondingly mount onto the connecting end 13 of the first tube 11 . The other end of the second tube 31 is formed with a second opening end 33 expanding outward. The inner surface of the second opening 33 of the second tube 31 is formed with a second guiding surface 34 that gradually reduces toward the mounting end 32 . A second stopping surface 35 is formed at the junction between the second guiding surface 34 and the inner surface of the mounting end 32 . When the mounting end 32 of the second tube 31 is mounted onto the connecting end 13 of the first tube 11 , the inner surface of the mounting end 32 of the second tube 31 exactly attaches to the outer surface of the connecting end 13 of the first tube 11 . Moreover, the second stopping surface 35 of the second tube 31 urges against the other end of the copper sleeve. This firmly fixes and limits the copper sleeve 21 , preventing it from falling off.
When assembling the invention, one first directly inserts the copper sleeve 21 into the connecting end 13 of the first tube 11 . Afterwards, the mounting end 32 of the second tube 31 is mounted onto the connecting end 13 of the first tube 11 . This renders the disclosed sleeve-type wire connector.
Please refer to FIG. 3 . When the invention is in use, one can insert two wires 41 , 51 into the two opening ends 12 , 33 of the first tube 11 and the second tube 31 , respectively. In this case, the core lines 42 , 52 of the wires 41 , 51 are guided respectively by the first guiding surface 14 on the inner surface of the first tube 11 and the second guiding surface 34 on the inner surface of the second tube 31 into the copper sleeve 21 smoothly. Therefore, one does not encounter any difficulty when connecting to the two wires 41 , 51 . This therefore increases the work efficiency of the user. Later on, the user simply uses a pinch (not shown) to pinch the connected mounting end and the connecting end, fixing the core lines 42 , 52 of the two wires 41 , 51 in the copper sleeve 21 for conducting an electrical current.
While the guiding surfaces 14 , 34 smoothly guide the core lines 42 , 52 of the wires 41 , 51 into the copper sleeve 21 , the skins 411 , 511 of the wires 41 , 51 are blocked by the guiding surfaces 14 , 34 . That is, the large-diameter ends of the guiding surfaces 14 , 34 exactly allow the insertion of the skins 411 , 511 . But the guiding surfaces 14 , 34 shrinking toward the connecting end 13 and the mounting end 32 block the skins 411 , 511 of the wires, now allowing only the core lines 42 , 52 of the wires to enter. This ensures the stability of the electrical conductivity of the wires 41 , 51 after the connection.
The disclosed sleeve-type wire connector has the following advantages:
1. The first tube and the second tube are integrally formed using an injection molding machine. They involve simple manufacturing processes and are suitable for mass production. Since the first tube and the second tube are connected by mounting, the assembly is simple and quick.
2. The first guiding surface of the first tube and the second guiding surface of the second tube in the invention smoothly guide the core lines of the wires into the copper sleeve. Therefore, one does not encounter any resistance when connecting the two wires. This easy assembly can effectively increase the work efficiency of the user.
3. The first guiding surface and the second guiding surface are delicately designed such that the wire skins are prevented from entering the copper sleeve, thereby ensuring the stability of electrical conductivity of the wires.
4. One end of the copper sleeve urges against the first stopping surface of the first tube. The second stopping surface of the second tube urges against the other end of the copper sleeve. Therefore, the copper sleeve is firmly fixed and limited so that it does not fall off.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to people skilled in the art. Therefore, it is contemplated that the appended claims will cover all modifications that fall within the true scope of the invention. | A sleeve-type wire connector comprises: a first tube having a first opening end and a connecting end, with a first guiding surface in the first opening end that can retract toward the connecting end thereof; a copper sleeve in the connecting end of the first tube; and a second tube having a connecting end corresponding to the connecting end of the first tube and a second opening end, with a second guiding surface in the second opening end that can retract toward the connecting end thereof. | 7 |
BACKGROUND OF THE INVENTION
This invention relates generally to turf care equipment and more particularly concerns an improved blade for a turf spiker for aerating turf and reducing surface filming effects.
By way of background, a turf spiker is a device which creates small cross-sectional area, relatively deep holes in a turf ground surface to allow air, moisture and other elements to penetrate the ground surface. The spike holes reduce surface filming effects and stimulate the growth of desirable grasses in the turf. One of the primary uses for a turf spiker is for spiking of golf course greens.
Because of heavy demand for continuous play on golf courses, it is highly desirable to have turf care equipment which conditions the turf without substantially interfering with play. This has been a drawback of prior turf spikers. Prior art turf spikers have had what might be referred to as a star-shaped blade. The individual teeth of the blade have generally been substantially symmetrical about a line from the tooth tip to the axis of rotation of the blade. In general the leading and trailing edges of each tooth in prior art spiker blades have been straight line segments so that the portion of the blade penetrating the ground surface has been V-shaped. This type of prior art blade may be referred to for simplicity as a "straight" star-wheel blade.
In turf spiking apparatus using the straight star-wheel blade at a setting at which the blade penetrates any substantial percentage of its radius, say greater than ten percent, a great deal of dirt, turf and other materials are lifted out of the spiker hole by the spiker blade and deposited forward of the spiker hole above the existing ground surface. This leaves a ruffled, unsightly appearance on the turf, especially on golf course greens. It also renders a green spiked with such a blade annoying and almost impossible to use for its intended purpose by golfers for a substantial time period after spiking of the green with such a blade occurs.
The present invention is a spiker blade which accomplishes the important function of aerating and penetrating the ground surface but is capable of doing so without undesirable "ruffling" that is, deposit of substantial amounts of turf and dirt above the ground surface resulting from the spiking process. Thus after use of the turf spiker of the present invention for aeration of the green, the green surface has a relatively smooth, unruffled appearance which allows use of the green for putting immediately after the spiking operation has occurred.
Furthermore, prior art turf spikers using traditional spiker blade configurations may be fitted with the present invention to enable them to eliminate the substantial shortcomings of prior art devices.
SUMMARY OF THE INVENTION
In accordance with the invention, a spiker blade adapted for mounting on the rotatable shaft of a turf spiker is provided. The spiker blade is configured with a plurality of teeth spaced about its periphery. Each of the teeth has a profile defined by its leading and trailing edges. The leading and trailing edges of the profile meet to form a tooth tip. The trailing edge of each tooth has a piercing segment leading upward from the tooth tip. Together with the entrance edge opposite the piercing segment these segments form a narrow tapered profile proximate the tip. Above the piercing segment on the trailing edge is a counterdepression segment directed at a substantially larger angle to said leading edge than said piercing segment.
In opeation, the spiker blade will be mounted to penetrate to depth so that the counterdepression segment comes into contact with the ground surface during spiking thereof. The counterdepression segment forms a counterdepression in the turf slightly in front of the normal area swept out by the piercing segment of the blade. This allows material lifted upward by the piercing segment to be deposited in the counterdepression below ground level, leaving virtually no ruffling above ground level.
In certain embodiments of the invention, the blade teeth will include an undercut segment separating the piercing and counterdepression segments of the trailing edges, the undercut segment sweeping out a lesser volume during spiking, therefore drawing less dirt, turf, and other material forward and upward during the spiking operation than would be lifted by a tooth without an undercut.
BRIEF DESCRIPTION OF THE DRAWING
Additional desirable features and advantages of the invention will become apparent upon particular reference to the drawings and detailed description which follow, in which:
FIG. 1 is a sectioned side elevational view of a turf spiker assembly showing one embodiment of a spiker blade constructed according to the present invention;
FIG. 2 is a greatly enlarged fragmentary view of a portion of the spiker blade of FIG. 1 with emphasis on the tooth profile to illustrate the important features of the profile characterizing the present invention; and
FIGS. 3 and 4 respectively are sectional, partially subterranean representations showing successive positions of a spiker blade tooth constructed according to the present invention and a conventional spiker blade tooth during turf spiker operation, and illustrating the effect of each on the ground surface as well as resultant migration of material.
While the invention will now be described in connection with preferred embodiments thereof, it will be understood that the invention is not limited in scope to those embodiments. On the contrary, all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the appended claims are covered.
DETAILED DESCRIPTION OF THE INVENTION
Turning first to FIG. 1, there is shown in section a turf spiker assembly generally designated 10. Although a specific embodiment of a turf spiker assembly is shown and described in connection with the present invention in the sectional view of FIG. 1, it should be clearly understood that the spiker blade construction of the present invention is not limited to use with such an assembly. In fact, any spiker in which the spiking blades rotate into contact with the turf surface for the purpose of spiking could be adapted for use with the present invention.
Turf spiker assembly 10 is illustrated with a section taken vertically through the turf spiker near one of the frame members thereof. Turf spiker assembly 10 rides on front and rear supporting rollers 12 and 14 respectively. Supporting rollers 12 and 14 provide rolling contact between turf spiker assembly 10 and a ground surface 16 defined by turf to be spiked. Assembly 10 includes two generally vertical frame members 18, only one of which is shown in the sectional view of FIG. 1. Extending horizontally and generally parallel between the two frame members are a tubular member 20, a spring tube 22 and front and rear supporting rollers 12 and 14. Tubular member 20, spring tube 22, rotatable shaft 24, and front and rear supporting rollers 12 and 14 are all shown in section in FIG. 1.
Mounted generally parallel to member 20, spring tube 22 and rollers 12 and 14 is a rotatable shaft 24. One end of rotatable shaft 24 is received in a one way slip clutch gear box 26. Gear box 26 is fastened to frame or housing 18 by means of a number of ears 28 extending outward from gear box 26 through which bolts 30 fasten into frame 18. The opposite end of rotatable shaft 24 may extend through bearing means in the frame member opposite frame member 18.
Considerable drawbar force, that is, force exerted in a direction parallel to ground surface 16, is required to move turf spiker assembly 10 forward and rotate the spiker blades of assembly 10 when the blades are in a penetrating position.
Due to this significant drawbar force requirement, the traction unit used to move the assembly may not be able to develop enough traction to smoothly move the assembly depending upon the turf condition, moisture content, soil type and other factors. Therefore it may be desirable to apply power to rotatable shaft 24 from gear box 26 through conventional power transfer means not shown in the figure. In this way, the drawbar force exerted on the turf spiker assembly by the traction unit with which it is used may be supplemented by additional drawbar force supplied by powering rotatable shaft 24.
Since the purpose of the turf spiker is to penetrate the ground surface rather than till it, it is vital that rotatable shaft 24 be powered to drive the spiker blades at a rate less than or equal to the forward motion of the tractor or prime mover with which the spiker assembly is used. In the turf spiker assembly shown in FIG. 1, this is accomplished by use of a gear box 26 with one way slip clutch which allows the rotatable shaft 10 to "free wheel" with no appreciable drag when the turf spiker assembly is pulled at a speed faster than it would normally travel under its own power.
Also, to assure that the traction unit is not driven by the power provided to the rotatable shaft, the gear box and associated power train may be designed to drive the spiker blades at a speed less than the resultant speed of the traction unit. For example, in one embodiment, the resultant speed of the spiker blades was designed to be 93% of or, 7% less than, the speed of the traction unit.
Keyed or otherwise fixed to rotatable shaft 24 by means of keys 32 is a spiker blade 34 constructed according to a preferred embodiment of the present invention. Although only one spiker blade 34 is shown in the sectional view of FIG. 1, it should be understood that a number of such spiker blades, say 8 or 10, would in the assembly be spaced along rotatable shaft 24 in different orientations to distribute the forces required for penetration and movement as evenly as possible over each revolution of shaft 24. Spiker blade 34 may be cut from a sheet of high carbon steel in a shape generally as shown in FIG. 1 or may be made from any other suitable material with strength and hardness appropriate to maintain its cutting edges. In one embodiment the spiker blades 34 were made from soft annealed, cold rolled steel 0.109 inch thick, then heat treated to give sufficient hardness.
Each spiker blade has a number of spiking teeth located about the periphery thereof. The teeth extend generally radially from the center of a hole provided for mounting of the blade on rotatable shaft 24. The normal direction of rotation of spiker blade 34 and rotatable shaft 24 is shown by an arrow on the blade 34.
In the particular embodiment shown, each tooth has a profile defined by a leading edge which is essentially a straight line segment and a trailing edge which includes a number of segments. One of the teeth on blade 34 has the leading edge thereof designated by reference numeral 36, and its trailing edge designated by reference numeral 38. These two edges meet to define a tooth tip 40. The details of spiker tooth construction and functions performed by various tooth segments are discussed in more detail in connection with FIG. 2.
Attached to tubular member 20 is a U-shaped lift bail 42. In FIG. 1, the U of the bail is in a plane substantially perpendicular to the plane of the figure. The lift bail receives a lift arm or lifting linkage (not shown) attached to the traction unit for lifting the turf spiker assembly from contact with the ground during turns or other times when spiking of turf is not desired.
Because turf spiker assembly 10 must exert a substantial downward force in order for the spiker blades to penetrate the ground surface, either the turf spiker must be heavily weighted or some downward force must be transferred to the assembly.
In the embodiment shown in section in FIG. 1, this is accomplished by means of a torsion spring arrangement which transfers forces from the traction unit to the spiker assembly. One end of a torsion spring 44 on turf spiker assembly 10 is fastened to spring tube 22 by means of a spring anchor bolt 46. Torsion spring 44 is helically wound about spring tube 22. The end of torsion spring 44 opposite the end anchored by bolt 46 extends generally tangentially outward from spring tube 22 and ends in a hooked portion 48. Hooked portion 48 extends through a U-shaped bracket 50 attached to tubular member 20 to a position proximate lift bail 42.
When the lift arm on the traction unit (not shown) raises assembly 10 by lift bail 42 to discontinue spiking, hooked portion 48 bears against bracket 50. However, when the lift arm lowers the turf spiker assembly to the ground surface the lift arm may engage hooked portion 48, effectively providing a point against which torsion spring 44 can flex and transfer its stored force through assembly 10 to the spiker blade teeth to aid in effective penetration of the ground surface.
FIG. 2 is a greatly enlarged fragmentary view of a portion of spiker blade 34 constructed in accordance with the present invention. Spiker blade 34 has a center of rotation 56. Extending from center of rotation 56 to tooth tip 40 is a radial line which will, for purposes of this specification, be defined as a tooth axis 58. To the right of tooth axis 58 is entrance edge 36 which, together with trailing edge 38, defines the tooth profile. Entrance edge 36 is in the specific embodiment shown essentially a straight cutting edge. Trailing edge 38, on the other hand, is constructed from a number of individual segments. Beginning from tooth tip 40 these segments include a piercing segment 60, which in the figure is a straight line segment making a sharp acute angle with tooth axis 58, a curved undercut segment 62 extending slightly back toward tooth axis 58 from a point of greatest width of piercing segment 60, and a counterdepression segment 64, which is a generally straight line segment in the figure.
Counterdepression segment 64 is directed more tangentially to the rotation center 56 than is piercing segment 60. Therefore, the portion of the tooth profile bounded by counterdepression segment 64 increases in thickness at a faster rate than the portion bounded by piercing segment 60.
Stated another way, counterdepressionn segment 64 makes a substantially greater angle with tooth axis 58 than does piercing segment 60.
Those of skill in the art will understand that the "ruffling" effect or migration of material caused by spiking will be minimized by minimizing the angle through which the tooth rotates while in contact with the turf and by minimizing the ratio d/r where d is the intended depth of tooth penetration, and r is the distance between the center of rotation of the spiker blade and the tooth tip. In order that counterdepression segment 64 may provide a place for the ruffled material to be deposited below the ground surface, the position of the counterdepression segment with respect to the remainder of the tooth profile is preferably maintained within predetermined limits. It has been found that the spiker blades constructed according to the present invention function more desirably if the position of the beginning of the counter-depression segment described as the limits of the distance P between the beginning of the segment and the center of rotation of the blade (identified by dotted line 66 in FIG. 2), is as follows:
(r- 0.90d) ≦ P ≦ (R- 0.55d) (1)
Where r is the distance from the center of rotation to the tooth tip and d is the intended depth of spike penetration. From industry standards, d will normally be between 0.75 inches and 2.50 inches. The constants 0.90 and 0.55 in the expressions above are the percentages of depth of spiker penetration that will not be disturbed by intrusion of the counterdepression edge. Stating the limits of P in words, the counterdepression segment functions most effectively to provide a counterdepression for deposit of ruffled material if it penetrates at least 10% of the total depth of spiked penetration, but it should not penetrate such a substantial portion of the total depth of penetration that in effect becomes a broad piercing segment.
The relative angle of the counterdepression edge is also extremely important. Turf and dirt displaced from the counterdepression area must be displaced in a downward direction to prevent ruffling ahead of the counterdepression area from occurring. The relative angle A of the counterdepression edge controls the direction of displacement. The angle A may be defined as the angle between counterdepression segment 64 and a straight line between the blade center of rotation and the beginning of the counterdepression segment (dotted line 66 in FIG. 2). The preferred range for the relative angle A is as follows: ##EQU1##
It should be noted that the constant 0.15 inches appears in this equation. This represents the maximum possible necessary ground clearance of the counterdepression segment. Expression (2) defines the limits within which the relative angle A can fall and still not significantly affect the direction that the material from the counterdepression segment is displaced, consistent with the limits placed on P by Expression (1).
Expression (2) means that the relative angle of the counterdepression segment must be small enough so that the counterdepression segment is not below the ground surface when the segment is horizontal, yet large enough so that the counterdepression dirt does not itself cause "ruffling."
To provide the most clearance for the spiker tooth as it rotates through the angle during which it is in contact with the ground surface, the value of the angle B between the tooth axis and the line from tooth tip 40 to the beginning of counterdepression segment 64 is important. The smaller this angle is, the more clearance is allowed. However, one can see that if this angle were selected too small the strength of the spiking tooth tip would be unacceptable. It has been determined that it is preferable to maintain this angle B less than or equal to 15 degrees, consistent with sufficient strength in the tooth tip to perform the spiking task.
In order to assure that the counterdepression segment results in an effective counterdepression area, it is desirable to maintain the length "L" of the counterdepression segment with preferred limits. These limits are set forth in the following expressions: ##EQU2##
If "L" were longer than the upper limit shown in expression (4), the counterdepression segment would tend to roll back down into the turf as the tooth completed its intended rotation. On the other hand if "L" were shorter than the lower limit which appears in expression (3), the counterdepression segment would not continue to and rise above the turf surface smoothly.
It should be clearly understood that the limits specified above are only preferred ranges for specific embodiments of the present invention. It is not necessary to the present invention that the spiker blade be constructed within all of the above limits. What is necessary is that the blade teeth be followed by some sort of counterdepression segment which creates a depression area by predominately compression force on the turf surface so that ruffled material lifted by the lower part of the tooth as it rotates through the earth may be deposited in the counterdepression area.
FIGS. 3 and 4 illustrate the operation of the present invention by contrasting sequential positions of a portion of a blade constructed according to the present invention with those of a prior art blade as turf spikers with the blades move from left to right across a ground surface 70.
FIG. 4 illustrates a prior art star-wheel spiker blade and its effect on the turf and ground surface. The sequence of tooth positions in FIGS. 3 and 4 are alphabetically labeled. Referring to FIG. 4, in position A the spiker blade tooth is beginning to pierce and penetrate surface 70 and is cutting into and downward through the ground surface. Positions B, C, and D show successive stages of greater penetration as the tooth moves downward and rotates toward a vertical position in the soil. At point E the blade is centered in the depression with the blade center of rotation directly over the tooth tip. Through the sequence of positions A, B, C, D, and E the turf and surrounding soil are put in compression by the movement of the tooth tip downward and forward into the turf. Continuing from position E in a cycloidal path, the tooth tip moves backward then forward and upward eventually clearing the ground surface. In so doing, the tooth sweeps out an area marked by crosshatching and identified with reference numeral 72. In positions occurring subsequent to position E, the trailing edge of the tooth is moving forward and upward. Friction between the trailing edge and the turf and soil draws the material previously in crosshatched area 72 forward of the hole above the ground surface to create a ruffle 74. This is the undesirable ruffle which the spiker blade construction in accordance with the present invention eliminates.
Referring now to FIG. 3, sequential positions of a portion of a spiker blade with teeth constructed according to the present invention are shown. In positions A, B, C, and D the entrance edge and the piercing segment of the trailing edge of a tooth pierce, penetrate and compress the turf and surrounding soil creating the basic depression. At positions D and E the counterdepression segment begins to contact and create a downward compression force on the ground surface slightly forward of the basic depression. As in FIG. 4, position E is the position at which the tooth tip is directly under the center of rotation of the spiker blade. After position E, the blade tooth tip rotates in cycloidal fashion backward then upward and forward and is lifted out of the hole by rotation of the spiker blade. As this occurs however, the counterdepression segment continues to move downward compressing an area shown by a crosshatched area 76. This provides a counterdepression immediately forward of the basic hole for deposit of material lifted by the spiker tooth as it is removed from the hole. From FIG. 3, it will be seen that the undercut segment of the trailing edge of the tooth allows the tooth to sweep out a significantly smaller area as it is being withdrawn from the hole. A crosshatched area identified with reference numeral 78 represents the area from which material will be displaced by the tooth upward and into the counterdepression area. Unlike the action of the spiker tooth of FIG. 4, the action of the spiker tooth of FIG. 3 creates no above-ground surface ruffle. The material previously present in area 78 is redeposited in counterdepression 76 below the ground surface. It is apparent that the improved spiker blade accomplishes spiking without creating ruffling at the turf surface.
From the foregoing description, it should be understood that it is not essential that the piercing or counterdepression segments of the trailing edge be straight line segments. It is sufficient that the piercing segment be configured to give as narrow as possible a tooth tip to minimize the amount of area swept out by the tooth tip, at the same time minimizing the size of the required counterdepression; and that the counterdepression segment exert a predominantly downward compression force so that it does not in itself cause above-ground ruffling of the turf.
While the improved spiker blade has been described in conjunction with specific embodiments and ranges of parameters it is evident that a number of alternatives, modifications, and variations will be apparent to those of skill art in light of this description. Accordingly, it is intended to embrace all alternatives, modifications and variations falling within the spirit and broad scope of the appended claims. | A spiker blade for use on a turf spiker assembly to break and ventilate a ground surface thereby facilitating penetration of air, water and nutrient through the surface. The spiker blade has a tooth profile with a trailing edge having a counterdepression segment. The counterdepression segment functions to create a ground surface depression into which ruffled material kicked up by the tooth during spiking may be deposited. As a result, the ground surface after spiking has taken place is maintained relatively smooth with an unruffled appearance. | 0 |
BACKGROUND OF THE INVENTION
[0001] In database processing systems, the user desires to have efficient, high speed access and search capabilities for data stored in the database. Crucial to this objective is the ability to enable fast retrieval of the correct data sought by means operating to find a match without having to search through each data element stored on each record.
[0002] Conventional database processing systems seek a match between input business data and stored data as set forth in U.S. Pat. No. 5,659,731, which is incorporated in its entirety by reference thereto. The '731 patent describes a system that accepts a given search entity from a user and utilizes a database to identify a possible matching entity from a large list of entries. The '731 patent also discloses a method which provides for evaluating the reliability of the matching entity. Preferably, the method is carried out with minimal human intervention. A user inputs a plurality of attributes to identify a given entity, the system identifies a possible matching entity, and assigns a numerical grade to reflect the match quality of each attribute. Thereafter, the method assigns a grade to each attribute score, assembles the grades into a key, uses the key to address a memory, and retrieves a confidence code or quality indicator from the memory. The confidence codes are based on empirical information and reflect the overall quality of the match for the particular entity.
[0003] Systems of the foregoing type are well known. For instance, in the credit industry, credit history information on a given business entity being considered for credit is typically processed through a commercially available database. A user may input the name of a business entity into a processor connected to the database, which then locates that given entity in the database and retrieves its credit history information. The credit history information is then used to make a decision on whether to grant or withhold credit for the given entity.
[0004] To simplify matters with a simple example, assume that the user has an interest in making a sale on credit to XYZ Corp., which is located at a particular address in a particular city. XYZ Corp. is the “given entity,” or “given entry.” After the user inputs this identifying information, the database is searched and an entry for XYZ Corp. located at a different address in the same city is identified from the database. A determination must then be made as to whether the identified XYZ Corp. is the same as the given entity XYZ Corp. If the determination is that they are the same, then the credit information from the database for the identified XYZ Corp. is used in making the credit decision for the transaction with the given entity.
[0005] Database systems such as these have far reaching applications beyond credit industry applications as illustrated above. In another illustration, a wholesale distribution entity may periodically distribute product information documents to retail entities. The costs associated with these documents may range from inexpensive product brochures (e.g., 50 cents each) to relatively costly product catalogs (e.g., $5.00 each). In order to save costs, since thousands of these product information documents may be distributed, the wholesale distribution entity may wish to direct the more expensive catalogs to those retailers having a high sales volume, and the less expensive brochures to retailers having a low volume of sales. In this application, the database system would be accessed to identify sales information on certain entities, as opposed to credit history information.
[0006] As will become apparent from the discussion that follows, the present invention is useful in broad-ranging applications, including both of the foregoing illustrations. In order to better explain the concepts and teachings on the present invention, however, the illustrations provided hereinafter will generally focus on the credit industry application presented above.
[0007] Business entities are typically listed in a database by what can be called attributes. The most common attributes are those which identify the entity, such as the business name and location. Location can be broken down into a number of attributes which include street number, street name, P.O. box number, city, town or the like, state (if in the U.S.) or country, and telephone number. These are common attributes which are found in many commercial databases reporting information on business entities. Other attributes are, however, sometimes utilized.
[0008] When it is desired to find a match for a given entity within such a list of business entities, inconsistencies in listing information can create matching problems. In some instances, inconsistencies can result from erroneous information stored in the database itself, and also from erroneous information input when identifying a given entity for whom a match is desired. In other instances, inconsistencies may result merely due to differing styles (e.g., abbreviations) used to identify certain attributes.
[0009] Credit departments typically have procedures for dialing up databases and obtaining credit information. Usually, the identification process is rather straightforward, and may be performed automatically. However, because of the different styles of stating names and addresses and the different care which is exercised by a large number of people in collecting information, the correlation between a given entity and the possible matching entities in the database do not always match precisely. When this occurs, human intervention is often necessary to make the intermediate determination as to which one of the one or more identified entities matches the given entity, before the ultimate determination of whether to grant or withhold credit can be made. Proper intermediate identification is particularly important in large dollar transactions. The human intervention usually involves either making an on-the-spot judgment as to the correct match, or making follow-up phone calls to investigate or verify the given entity.
[0010] Based on the amount of time required to verify the identity of a given entity, and the cost associated with the human (e.g., credit manager, clerk, etc.) who makes those decisions, it will be found that this somewhat mundane step in the credit approval procedure can consume a significant amount of dollar resources. Indeed, in situations where a large number of such credit decisions are made, it is found to be commercially feasible to isolate a subset of justifiable risks (i.e., those where a reliable match is made), and grant credit to those risks without the need for human intervention.
[0011] There are generally available processes and procedures, and commercially available software packages for determining a “best fit” match for any given entity within a large compilation or list of entities. For example, a system known as Soundex is well known and has long been used to find words that sound similar but are spelled differently. Similarly, a system known as AdMatch was used to help people find the proper 1970 census tract, using a base address.
[0012] In the credit industry, systems like the foregoing are used by credit reporting agencies to identify a list of possible matching entities and numerically score the match of the identifying attributes (name, address, city, etc.) for each entity identified. More particularly, automated matching systems are available, which parse, normalize, and further process a given entry to identify likely matches. These systems can also provide attribute-by-attribute information, such as a numerical score, reflecting the reliability of the match of each attribute. Thus, a user might be faced with an attempted match where the name matches exactly and thus has a 100% score, the street address has a 63% score, the town 79%, and the phone number a no entry condition. But, again, human intervention is usually required as a credit manager, clerk, or other appropriate person must examine the entries, the scores, and the overall context of the request in order to determine whether the information provided by the credit database indeed matches the characteristics of the given entity.
[0013] More sophisticated systems are known, wherein the individual attribute scores are weighted by factors based on empirical data to produce a composite score. These systems have been less than effective in the past, and it is typically found that programmers are continuously adjusting weighting factors to accommodate new conditions. As additional empirical data is collected, the weighting algorithm be further refined. Thus, it can be appreciated that the weighting function or algorithm is a ever-changing device. Unfortunately, while the newly adjusted weighting factors may accommodate a new condition successfully, they often unexpectedly and adversely affect other computations, and accurate matching problems persist.
[0014] The unique fuzzy matching system according to the present invention creates a tunable, self-directing approach that focuses on those algorithmic components that are most likely to yield positive results. This system enhances all online and batch matching environments, and significantly increases data throughput. The present invention also provides the following advantages over conventional matching systems: (1) enhanced reference database; (2) advanced approaches to retrieve keys including geo-coding and advanced name scoring; (3) improved presentation of candidates for online decisioning; (4) enhanced decisioning criteria and communication about how a match was performed; and (5) focused measurement of match performance at critical internal touchpoints as well as customer-facing metrics.
SUMMARY OF THE INVENTION
[0015] There is provided a method for searching a database to obtain data. The method includes (a) prioritizing a set of keys that are derived from a match inquiry, thus yielding a prioritized set of keys, wherein the prioritizing is based on, for each key of the set, an efficacy of using the key, (b) determining a subset of the prioritized set, and (c) retrieving, using the subset, a set of candidates for satisfying the match inquiry.
[0016] One aspect is a method of searching and matching input data to stored data. Input data is received that has a plurality of elements and represents a business entity. Selected elements are converted to a set of terms. Based on the terms, stored data is searched for a plurality of match candidates. A best match is provided from the match candidates.
[0017] In some embodiments, converting elements to terms includes parsing, cleaning, and standardizing steps. The elements are parsed to identify the terms, including a company name and an address. The terms are cleaned, including removing extraneous words and the terms are standardized. In some embodiments, converting includes validating, correcting, and assigning steps. An address having a street name and city name is validated. The street name and city name are corrected, if necessary. A zip code, a latitude, and a longitude are assigned to the set of terms. In some embodiments, converting also includes maintaining at least one reference table. In some embodiments, additional converting is performed. Special characters in the terms are removed. A last word in the company name is removed if it is a standard company form. The text in the terms is converted to uppercase. Select text in the terms is depluralized. Select words in the terms is standardized. Select phrases in the terms are normalized. A street number and a street name are extracted from the address.
[0018] In some embodiments, searching includes several more steps. A plurality of keys are generated from the terms. Match candidates are limited for certain keys that return counts surpassing a predetermined threshold. A cost function is generated for select key intersections. Key intersections are prioritized according to the cost function. Match candidates are retrieved in order of the key intersections. In some embodiments, a confidence score is generated for each match candidate based on a degree of match.
[0019] In some embodiments, an ordered list is provided of selected match candidates based on their confidence score. In some embodiments, the confidence score is based on comparison scoring. In some embodiments, comparison scoring has additional steps. A score is determined for a business name, a street name, and a city name in a pair. The pair is the terms and one of the match candidates. The pair is classified into data segments using a decision tree. Logistic modeling is performed using the data segments. A match probability is determined for the pair. A grade is assigned to the pair. In some embodiments, comparison scoring includes determining a uniqueness score based on the number of matching business names in the city name. In some embodiments, comparison scoring includes calculating a business density score for the pair. In some embodiments, comparison scoring includes calculating a zip score. In some embodiments, comparison scoring includes calculating an industry score by matching words in the business name to standard industrial classification (SIC) key words.
[0020] Another aspect is a system for searching and matching input data to stored data comprising a web services interface, a pre-processing layer, an application layer, and a database layer. The web services interface accepts a match request and provides a best match. The match request includes input data representing a business entity. The pre-processing layer has a cleaning, parsing, and standardizing component for converting the input data into a set of terms. The application layer has a match engine for processing the match request using the set of terms and produces the best match. The database layer retrieves match candidates from stored business entity information for the application layer. In some embodiments, the match engine comprises a decisioning component. The decisioning component determines the best match and an ordered list of match candidates. In some embodiments, the web services interface also provides an ordered list of match candidates from the application layer. In some embodiments, the system also comprises a plurality of memories, asynchronous message queues, and caching systems. These are in the pre-processing, application, and database layers.
[0021] Another aspect is a computer readable medium having instructions for performing a method of searching and matching input data to stored data. A match request is received. The match request has a plurality of elements representing a business entity. The elements are pre-processed to convert them into a set of terms. Match candidates are retrieved by searching a database based on the set of terms. The match candidates are evaluated to determine a best match and the best match is provided. In some embodiments, pre-processing elements comprises additional steps. The elements are parsed to identify the set of terms, including a company name and an address. The terms are cleaned, including removing extraneous words and the set of terms is standardized. In some embodiments, retrieving match candidates comprises additional steps. A plurality of keys are generated from the terms. Match candidates are limited for certain keys that return counts surpassing a predetermined threshold. Key intersections are prioritized according to a cost function. Match candidates are retrieved in order of the key intersections. In some embodiments, evaluating match candidates includes additional steps. A score is determined for a business name, a street name, and a city name in a pair. The pair is the set of terms and one of the match candidates. A uniqueness score is determined based on the number of matching business names in the city name. A business density score and zip score are calculated for the pair. An industry score is calculated by matching words in the business name to standard industrial classification (SIC) key words.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present invention, and together with the description serves to explain the principles of the invention. In the drawings:
[0023] FIG. 1 is a block diagram of a system, preferably including a network, for carrying out the basic process of the search and match system of the present invention;
[0024] FIG. 2 is a block diagram depicting the arrangement by means of a suitable program for accomplishing or fulfilling the process of the present invention;
[0025] FIG. 3 is a diagram the three step process of cleaning and parsing, candidate retrieval and decisioning according to the present invention;
[0026] FIG. 4 is a block diagram detailing the individual steps which occur in the three step process describe in FIG. 3 ;
[0027] FIG. 5 is a block diagram similar to FIG. 4 and including the step of connecting to a web service;
[0028] FIG. 6 is a diagram depicting the objective, input and output of the cleaning, parsing and standardization step of FIG. 3 ;
[0029] FIG. 7 is a block diagram depicting the cleaning, parsing and standardization data flow of FIG. 6 ;
[0030] FIG. 8 is a diagram depicting the objective, input and output of the candidate retrieval step of FIG. 3 ;
[0031] FIG. 9 is a block diagram depicting the candidate retrieval data flow of FIG. 8 ;
[0032] FIG. 10 is a diagram depicting the objective, input and output of the measurement, evaluation and decision step of FIG. 3 ;
[0033] FIG. 11 is a block diagram depicting the measurement, evaluation and decision data flow of FIG. 10 ;
[0034] FIG. 12 is a block diagram of a name score model according to the present invention;
[0035] FIG. 13 is a block diagram of a uniqueness score model according to the present invention;
[0036] FIG. 14 is a block diagram of a latitude and longitude business density score model according to the present invention;
[0037] FIG. 15 is a block diagram of a zip score model according to the present invention;
[0038] FIG. 16 is a block diagram of a industry score model according to the present invention; and
[0039] FIG. 17 is a block diagram of the application architecture according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0040] Referring now to FIG. 1 , there will be seen a communication system 10 , which includes a computer system 12 , a communication network 14 , a database 15 , a match engine 17 , input search data 19 , output database match records 21 , and a user interface 16 . The communication network may be any wired or wireless network capable of conducting communication between functional modules.
[0041] The user interface may be connected in the case where a suitable customer device may be chosen for operation. In addition to access through the communication network by use of the user interface, there is also provided an operator device 18 , seen in FIG. 1 , such that a service operator may gain access by way of the network 14 to the input data source and to all the other functional modules and components, including the computer system 12 so that a vendor may operate to accomplish the searching and matching task at hand for a customer.
[0042] It will be understood by reference to FIG. 2 that the operating system program 76 and the search and match program 78 are stored in memory 72 so that they may be utilized in the running the system to accomplish the heretofore noted objectives. Conventional components in the form of processor 70 and a bus bar 74 for connecting inputs and outputs to the computer system are also depicted in FIG. 2 .
[0043] FIG. 3 is a schematic representation of the decision making operation according to the present invention, wherein each inquiry data is cleansed and parsed 20 , followed by candidate retrieval 22 and finally a decision 24 . Cleansing and parsing step 20 involves (a) identification of key components of the inquiry data, (b) name, address and city normalization, (c) name consistency, and (d) address standardization. The candidate retrieval step 22 involves (a) gathering of possible match candidates from the reference database, (b) use of keys to improve retrieval quality and speed, and (c) optimization of keys based on data provided during inquiry. The decisioning step 24 involves (a) evaluation of matches according to a consistent standard, (b) matchgrade processing, (c) confidence coding, and (d) confidential percentile generation.
[0044] FIG. 4 is a block diagram which more specifically describes the decision making operation of the present invention, wherein cleaning and parsing step 20 requires the parsing of name and address elements and removal of extraneous words in step 26 . The parsed and cleaned name and address elements are then standardized in step 28 which validates the address, check to determine if the street and city names are correct, and assigns a zip code plus 4 and latitude/longitude. Standardization step 28 checks with reference table 30 which maintains a database of tables for vanity city and vanity street names.
[0045] The candidate retrieval step 22 in FIG. 4 received the cleaned, parsed and standardized data from step 20 for which it then generates keys 32 used for retrieval of candidates from reference database 34 . Thereafter, the keys are optimized to retrieve 36 effectively from reference database 34 . Reference database 34 establishes and maintains reference tables for searching by key construction 32 and search strategy/candidate retrieval 36 .
[0046] Candidate retrieval step 22 is followed by measurement, evaluation and decision step 24 , wherein the data from step 22 is measured 38 and then evaluated and decided upon in sub step 40 . Measurement sub step 38 involves the development of a measurement of confidence score (or degree of match) between an inquiry and a candidate. This information is then sent to evaluation and decision sub step 40 which establishes an order for which each candidate is presented in online and selection of the best candidate in the batch.
[0047] FIG. 5 is a similar block diagram to FIG. 4 , above, but also depicts the connection of the web services 42 to cleaning, parsing and standardization step 20 . Web services 42 includes an HTTP server 44 which accepts requests for data and application server 46 which processes XML requests an converts them into JAVA objects. Application server 46 also processes JAVA objects and converts such JAVA objects into XML format before forwarding to cleaning, parsing and standardization step 20 .
[0048] FIGS. 6 and 7 are block diagrams detailing the subroutines required for the cleaning, parsing and standardization step 20 . In particular, FIG. 6 describes the objectives 48 , e.g., remove all special characters (e.g., ˜, @, /, *, etc.), the input 50 , e.g., raw inquiries, and the output 52 , e.g., cleaned inquiry. FIG. 7 demonstrates the data flow in step 20 , wherein first logic data right step 54 removes the special characters, first logic ACE step 56 then parse and corrects the street address and generates latitude/longitude, plurals step 58 removes plurals, word standardization step 60 standardizes words, and phrase normalization step 62 normalizes phrases.
[0049] FIGS. 8 and 9 are block diagrams detailing the subroutines required for the candidate retrieval step 22 . In particular, FIG. 8 defines the objective 64 , e.g., retrieve optimal candidates that are likely to be matches, input 66 for cleaning inquiry, and output 67 for generating matched candidates. FIG. 9 demonstrates the data flow in step 22 , wherein inquiry step 68 involves Escoffery Acquisition, key generation step 80 which generates valid keys from information available from a clean inquiry, count step 82 which reads frequency counts for all valid keys and throttles keys that return more candidates than the present throttle limit, key sequence generation step 84 which generates cost function (e.g., retrieval time, intersection time, matchgrade time and overheads) for valid key intersections, prioritization step 86 which rearranges key intersections in order of increasing cost, moving from tight to loose, match, effectiveness and throttle, and retrieval step 88 which retrieves candidate lists from database in order of key intersections.
[0050] FIGS. 10 and 11 are block diagrams detailing the subroutines required for measurement, evaluation and decision step 24 . In particular, FIG. 10 describes the objectives 90 for assigning accurate probability of match and confidence code to an inquiry candidate pair by measurement of element score, assignment of confidence code and 2 msec/candidate, input 92 which cleans inquiry and candidate information, and output 94 which provides eleven element scores via match string, MDP and confidence code and probability. FIG. 11 involves the data flow of step 24 , wherein inquiry data 96 and candidate data 98 are sent to scoring algorithm 100 for grading. The graded inquiry and candidate data is then sent from scoring algorithm 100 to match string 102 and confidence code (CC) table 104 .
[0051] FIG. 12 demonstrates a preferred name scoring model for use with business names, street name and city name. Inquiry data 106 and candidate data 108 are sent for comparison scoring 110 followed by classification 112 into one of eleven distinct data segments by means of a decision tree, logistic modeling 114 which uses data segments and other descriptive variables as predictors, probability analysis 116 where the probability of good match that would be consistent with human judgment is determined, and A, B, F, Z grading 118 where the grading is standardized to convention frequencies.
[0052] FIG. 13 is a logic diagram for uniqueness score pertaining to, for example, city name matches. The uniqueness score works as follows. If the city names match 120 then count matching business names in city 122 and score 124 the number of matches based upon 100 . This is useful if match decision cannot be made based on street address, phone and post office box 126 . If the city name does not match 120 , then count matching business names in state 128 and score 130 the number of matches based upon 100 . This is useful if the inquiry lacks valid city name 132 .
[0053] FIG. 14 is a block diagram that provides a latitude/longitude business density score which is useful to assess proximity when inquiry may contain errors in street address or city name which are more common in areas of high population density, e.g., northern New Jersey. In this type of scoring the inquiry latitude/longitude 134 based on city and/or street address is analyzed together with the candidate latitude/longitude 136 based on city and/or street address. The distance 138 is determined by the latitude/longitude distance between the inquiry and candidate. Simultaneously, the inquiry count (A) 140 , i.e., count of businesses in the inquiry city, and the candidate count (B) 142 , i.e., count of businesses in candidate city are scored 144 using the equation 100/D(log(A+B)+1 which is indicative of the business weighted distance.
[0054] Another scoring technique that is useful according to the present invention is zip scoring set forth in FIG. 15 . Zip scoring is useful to improve match effectiveness when inquiry includes zip code but is otherwise incomplete or ambiguous. The logic diagram in FIG. 15 feeds an inquiry zip code 146 and a candidate zip code 148 into a decision tree 150 . Decision tree 150 determines if the first two digits are in the same state for both the candidate zip code and the inquiry zip code. If not in the same state then zip score is zero. If they are both in the same state the two zip codes are sent to analyzer 152 which determines the edit distance of last four characters of each zip code. If the edit distance of last four characters of each zip code is 0 or 1 then the zip score is 100, if 2 then zip score is 80 if 3 or more than zip score is zero.
[0055] FIG. 16 depicts an industry score which is useful to enhance match when business name is inaccurate. According to the industry scoring technique according to the present invention the inquiry 154 , e.g., “farmer John's meat market” has its words matched 156 in name to SIC key words via reference table 158 . A list of possible inquiry standard industry classifications (SIC's) 160 are generated and matched 162 with a similar list of possible candidate SIC's generated from 164 , wherein the score is 100 if any SIC matches occur between the inquiry and candidate SIC's, otherwise the score is zero.
[0056] FIG. 17 provides a block diagram of the application architecture according to the present invention. The use of extensive memory and asynchronous message queues enables the system to achieve high throughput, i.e., use of a standard web-service interface allows for easy interoperability with other systems. In its simplest detail, the application architecture of FIG. 17 includes online protocol adapters 170 , 172 which receive online requests (IR) and batch requests (IR), respectively. These requests are sent to pre-processing layer 174 where they are processed in a pre-processing layer listener/acceptor processor 176 , queue 178 and cleaning, parsing and standardize processor 180 . The cleaned, parsed and standardized data is then either transmitted to sender 182 or first level caching system 184 . If sent to system 184 then the information is then processed via output gatherer/separator 186 and then delivered to reporter 188 . If sent to sender 182 , then it proceeds to application layer 190 where it is processed by application layer listener/acceptor 192 , queue 194 and match strategy 196 . Match strategy 196 includes key construction 198 , measurement 200 and evaluation and decision 202 . Match strategy 196 transmits keys via sender 204 to database layer 206 , which receives such keys via key acceptor 208 . Key acceptor thereafter forwards such keys to database 214 via queue 210 to candidate retriever 212 . Candidate retriever 212 also acts to retrieve candidate information from database 214 and thereafter transmit it to match strategy 196 via sender 216 and candidate acceptor 218 . The match candidate output from match strategy 196 is returned to pre-processing layer 174 via output sender 220 where it is received by output listener 222 and then sent to output gatherer/separator 186 . Additionally, output from match strategy 196 is transmitted to retrieval caching system 224 which has a memory centric architecture which reduces candidate retrieval time. Database 214 receives data from database caching system 226 , update data feed 228 and AOS data 230 , buy data 232 and reference key generator 234 . Database 214 is connected to backup/recovery system 236 to protect against any data loss.
[0057] The invention having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.
[0058] What is claimed is: | There is provided a method for searching a database to obtain data. The method includes (a) prioritizing a set of keys that are derived from a match inquiry, thus yielding a prioritized set of keys, wherein the prioritizing is based on, for each key of the set, an efficacy of using the key, (b) determining a subset of the prioritized set, and (c) retrieving, using the subset, a set of candidates for satisfying the match inquiry. | 8 |
BACKGROUND OF THE INVENTION
Peristaltic pumps are known in the art as devices for precision pumping of various liquids, mixtures of liquids and solids, etc. The pump involves a flexible tube through which the pumped liquid passes. Rollers press the flexible tube against an outer wall capturing a precise volume of liquid between adjacent rollers which volume is discharged from the pump outlet. The servicing and repair of pumps in general usually involves hiring a mechanic who requires special tools and know-how to repair the pump. In the case of peristaltic pumps which are frequently used in connection with residential swimming pools, it has been considered to be highly desirable if the pump could be repaired easily by the home owner who had little or no mechanical capabilities.
It is an object of this invention to provide a pump housing wherein the cover and the housing are releaseably connected by a snap-fit closure means. Still other objects will be apparent from the more detailed description which follows.
BRIEF DESCRIPTION OF THE INVENTION
This invention relates to a peristaltic pump having a housing, a roller assembly, a flexible feeder tube, and a housing cover wherein the improvement comprises a tapered tongue member around the outer perimeter of said housing adapted to frictionally engage a recess around the outer perimeter of said housing cover to close tightly said cover onto said housing without need for additional fastening means.
In specific embodiments the tongue member is a cylindrical projection concentric with the housing and projecting outwardly therefrom, the inside surface of the tongue being generally cylindrical and parallel to the axis of the housing while the outside surface is frustoconical with the larger diameter at the free end of the tongue. This combination produces a tightly fitting snap-on connection between the housing and the cover.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a top plan view of a peristaltic pump having the features of this invention.
FIG. 2 is a side elevational view of the pump of FIG. 1.
FIG. 3 is a front elevational view of the pump of FIG. 1.
FIG. 4 is a cross-sectional view of the snap-fit connection taken at 4--4 of FIG. 1.
FIG. 5 is a top plan view of the cover of the pump housing.
FIG. 6 is a front elevational view of the cover of FIG. 5.
FIG. 7 is a bottom plan view of the cover of FIG. 5.
FIG. 8 is a top plan view of the housing body of pump housing.
FIG. 9 is a front elevational view of the housing body of FIG. 8.
FIG. 10 is an enlarged view of area 25 of FIG. 9.
FIG. 11 is a bottom plan view of the housing body of FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
In the attached drawings there are shown the features of this invention. The peristaltic pump includes a housing 15 and a cover 18 enclosing a flexible feeder tube 17 and a roller assembly 16. In such a pump the roller assembly 16 has three or more rollers between a pair of spaced plates 16' which are rotated while pressing tube 17 against the inside wall of housing 15. This produces a volume of liquid inside tube 17 between adjacent rollers of assembly 16 which is forced out of tube 17 as the assembly rotates. If roller assembly 16 as seen in FIG. 1 rotates counterclockwise, the suction side of the pump is inlet end 27 of tube 17 and the pressure side of the pump is outlet end 28 of tube 17. Housing 15 and cover 18 provide an enclosure for roller assembly 16 and anchor points for tube 17 near its two ends. Housing 15 is attachable to the housing of a driving means, which normally includes an intermittent drive and electrical motor (all not shown) by means of slots 29 which cooperate with screw heads on the housing of the driving means. The motor shaft 31' passes through hole 30 in the bottom of housing 15, is affixed to plates 16' of roller assembly 16 by means of a flattened portion of the shaft 31', and is supported in bearing 31 in cover 18. Peristaltic pumps are known in the prior art as evidenced by my patent, U.S. Pat. No. 3,756,752 which shows such driving means and prior art pump.
In accordance with this invention, cover 18 is removably attachable to housing body 15 by a snap-fit attachment which does not require any additional fastening devices. This is achieved by the cooperation of a tongue 19 on housing 15 with groove 26 on cover 18. Tongue 19 projects upwardly in a generally cylindrical configuration from the upper surface 32 of housing 15. Tongue 19 has an inner surface 20 which is generally cylindrical about longitudinal axis 33 of housing 15. Outer surface 21 is frustoconical with outer end 34 of tongue 19 being larger in diameter than inner end 35. Angle 22 between surface 21 and axis 33 is about 5°-15°, preferably about 10°. Correspondingly, angle 24 between surface 21 and surface 32 is about 75°-85°, preferably about 80°.
Groove 26 in cover 18 is substantially similar in shape to tongue 19 so as to fit tightly over tongue 19 with a snap-fit. The inside wall of groove 26 is cylindrical and the outside wall has a frustoconical surface identical to surface 21 of tongue 19. Because of the tight fit between tongue 19 and groove 26 there are one or more relief grooves 36 intersecting groove 26 to permit the free flow of air into and out of groove 26 when cover 18 is removed from or attached to housing 15. Grooves 36 also serve to permit water to flow through in the event water should get inside housing 15. It will be seen that outer end 34 of tongue 19 must be slightly deformed or compressed in order for groove 26 to receive tongue 19 in a mating engagement. This deforming compression results in a snap-fit holding cover 18 tightly against housing 15.
Housing 15 and cover 18 are preferably made of tough plastic such as polysulfone, polycarbonate, polyacetal, polyamide, polyvinylchloride, or the like, so as to provide the necessary resilience and corrosion resistance. Preferably, these plastics are reinforced with fibers of glass or other inert materials to provide greater strength properties, and are substantially transparent.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention. | A housing for a peristaltic pump including a housing body, a roller assembly, a flexible feeder tube, and a cover, the improvement comprising a cylindrical tongue on the housing and a mating groove on the cover adapted to provide a snap-fit releaseable closure. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This non-provisional patent application claims priority to the provisional patent application having Ser. No. 61/688,670, filed on May 18, 2012.
FIELD OF THE INVENTION
[0002] This invention relates to a check valve, and more specifically a check valve for use in an airflow line that facilitates the unloading of granular and related bulk material from tank trailers, railroad cars, and other conveying facilities, and particularly a check valve where its biasing spring is totally encapsulated so that when the spring deteriorates and breaks due to fatigue, the parts of the spring are enclosed within the housing and do not enter into the flow of air, or the granular material, to cause any contamination. Also with a cone shaped poppet helps facilitate the air flow thru the valve without causing turbulence and generating heat as previous design flat poppets in swing gate check valves in the industry do.
BACKGROUND OF THE INVENTION
[0003] Generally, means for conveying of dry bulk material, within systems, has long been used in the art. Pressurized air, translated into air flow, is used to aid in the transfer of the granular material particularly as it is being unloaded from a tank trailer, or other means of conveyance. Within such systems, check valves have been used within the airlines to form the air source control means that allows the pressurized air to flow in one direction, towards the bulk material, to aid in its conveyance. But, the check valves also have a primary usage of attaining closure, as the flow of air ceases, and thereby prevent the granular material from back flowing through the air line, and to cause contamination and blockage within the system, after usage. In any event, the check valve is used to prevent the dry bulk material from running backwards and getting into the air source and blocking up or ruining the blower or compressor which is used to pressurize the air, and to furnish the flowing air source to unload the materials. When there is a back flow of the dry bulk material, it can plug up the total unloading system.
[0004] In the past, there have been some developments in the types of check valves used under these circumstances, such as a swing gate or flapper type valve was predominantly used in the system, as a means to control the flow of air, and to prevent back sourcing of the bulk material, particularly towards the source of its unloading air. In a flapper type check valve or flat poppets, this back flowing of bulk material can occur.
[0005] There have been check valves that have used for this purpose, but as with the swing gate or flapper type of check valve, their biasing springs, usually of a torsion type, generally were exposed to the passing air, which means that when the check valve or flapper valve breaks, and more particularly its spring fractures, parts of the broken spring are conveyed along with the air source, or flowing pressurized air, becomes entrained within the granular bulk material being conveyed, and thereby can contaminate the entire load which prevents it from being used. This day and age, with product liability suits predominating, having someone chew a piece of spring within a cereal, or other related product, or having a piece of spring embedded with a molded plastic part, could lead towards costly injury, damage, and litigation.
[0006] It is as result of these types of detriments that can occur through the use of the prior art of valves, the current invention has been designed to obviate can minimize the chances of occurrence of these predicaments.
SUMMARY OF THE INVENTION
[0007] This invention is generally a horizontal style of check valve, but it can be used in vertical positions also, that applies a coil spring instead of a torsion spring, or other types of exposed springs as were used with the swing gate type of check valve, or even a check valve that has its spring readily exposed to the down stream side of the valve, so that the biasing spring of this improved check valve provides a coil spring that is totally encapsulated within its valve structure, so that if it would break, it is contained entirely within the pocket that houses the spring for the check valve, and it cannot send its broken pieces down the air stream and contaminate the material being pneumatically conveyed. In addition, the structure of this current valve is that it is made of a lesser number of parts, many of its parts are integrated together, which means there are relatively few moving parts for the check valve, other than the valve itself, while the biasing spring part of the check valve and its poppet, as stated, are generally encapsulated within the structure of the spring housing that holds the poppet valve, and is not exposed directly to the passing pressurized air.
[0008] Furthermore, the guide bushing used in the check valve of this current invention, is located on the down stream side of the flow chamber, and therefore, reduces the amount of restriction to the flow of the passing pressurized air, during its conveyance through to the unloading system. Thus, as compared to the prior art devices, there is much more open area to the check valve of this invention, providing less restrictive areas for the air to flow, thus providing no impediment against air flow, through the valve, during operations of the air conveying system. This is generally achieved through the use of a bell housing design that enlarges the air flow path.
[0009] Hence, the structure of the check valve of this invention incorporates a housing, that is streamlined in its design, that allows a greater area surrounding the check valve for the flow of air to pass therethrough, when the pressurized air opens up the valve, and enhances the air flow, rather than acting as a restrictor, as was provided with and encountered when using the prior art type of swing gate valves, or related types of check valves.
[0010] The concept of this invention is to provide a check valve that is used in an air flow line that allows for the flow of air through the air line, past the check valve, for use for unloading a tank trailer, or the like. It incorporates a housing, the housing incorporates a valve seat, the housing does have a widened contour at the location where the check valve, when opened, provides a greater capacity for the pressurized air to pass thereby, thereby not reducing or restricting the pressure of the flowing air, that will be needed to aid in the conveyance of the bulk granular material, during its unloading. A check valve is provided within a bushing, formed of the housing, and the check valve is normally seated enclosed against the valve seat, as when the system is shut off. But, when pressurized air flows through the air flow line, as generated from a compressor, a pump, or the like, further upstream, the check valve becomes unseated, as a result of the bypassing pressurized air, that allows the air to flow through said air line, past the check valve, and to the location where it aids in the conveyance of the granular material, through the material flow line for unloading.
[0011] The check valve has a stem connected to it, and the valve stem is provided for locating within a channel provided within the bushing, and encloses a spring around the valve stem, within the bushing channel, and keeps it encapsulated entirely therein, so that when the spring may fatigue, and break into parts, due to reaching excessive unloading cycles, the broken parts of the spring remain entirely enclosed within the bushing channel, and do not enter into the flow of the passing air, nor can it contaminate the flowing air, or attain access into the flowing granular material, that avoids its contamination.
[0012] It is, therefore, the principal object of this invention to provide means for substantially reducing the exposure of parts of a check valve, within an air flow line, so that when fatigue of any moving part occurs, it is totally contained and cannot enter into the flow of air, or the granular material being conveyed thereby.
[0013] Still another object of this invention is to provide a housing for a check valve that furnishes wider dimensions and a greater flow path for the flowing pressurized air, so as to substantially reduce the incidence of any pressure drop, for the passing pressurized air, as used for unloading of dry bulk materials.
[0014] Another object of this invention is to provide means for mounting of the bushing that holds the poppet within the check valve, comprising at least a pair of ribs that may be contoured so as to reduce any resistance to the flow of air there passed, during its usage within an air flow line of an unloading system.
[0015] Still another object of this invention is to provide at least a pair of ribs, for holding a bushing for supporting a poppet within a check valve, where the ribs are designed to induce some degree of spiraling flow to the passing pressurized air, to aid in the movement of the dry bulk granular material through its flow line as induced through the impingement of the pressurized air entering from the connected air line.
[0016] These and other objects may become more apparent to those skilled in the art upon review of the summary of the invention as provided herein, and upon undertaking a study of the description of its preferred embodiment, in view of the drawings.
DESCRIPTION OF THE DRAWINGS
[0017] In referring to the drawings,
[0018] FIG. 1 provides a side view of the air flow check valve of this invention;
[0019] FIG. 2 is a left side view of the check valve of FIG. 1 ;
[0020] FIG. 3 is a vertical sectional view taken through the check valve along line 3 - 3 of FIG. 2 ;
[0021] FIG. 4 is a similar view to the section of the check valve as shown in FIG. 3 , but in this instance its poppet is forced open by the flow of air, to allow the pressurized air to flow therepast during performance of an unloading procedure through use of the system;
[0022] FIG. 5 is a sectional view showing the mounting ribs and the bushing for holding the poppet in place, taken along the line 5 - 5 of FIG. 3 ;
[0023] FIG. 6 provides an enlarged view of the bushing, the stem of the poppet, and the encapsulating of the biasing spring totally within the channel of the bushing, as taken along the line 6 of FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] The concept of this invention is to provide a check valve for use in a pressurized air flow line, that can function to prevent the back flow of granular material being conveyed by the system, when the system flow is curtailed; to provide a check valve that is contoured to provide for both uniform flow of pressurized air therethrough, without any pressure reduction, and to also introduce a spiraling flow to the passing air as it moves through the air flow line and enters into the granular material flow line, to induce flow of the granular material during its unloading.
[0025] In view of these features, and improvements to an air line check valve, the concept of this invention is generally shown in FIG. 1 , wherein this embodiment for the horizontal air flow check valve 1 is shown secured within the air flow line 2 through an arrangement of a series of fasteners 3 that secure the flanges of the air flow line, as at 4 , with the flanges of the check valve, as noted at 5 . The air of the air flow line passes generally in the direction of the arrows 6 and on the downstream side, usually the air flow line will connect by means of a tee (not shown) and empty its pressurized flowing air into a bulk material conduit, that unloads its dry granular material through the efforts of the passing air to a location for unloading.
[0026] FIG. 2 shows a left end view of the check valve, and its flange 5 , as previously described, and is readily disclosed. Furthermore, the housing 6 for the check valve is noted. In addition, the air intake can be seen at 7 and the front of the valve poppet is noted at 8 , seated within the housing 6 , as understood. A cone shaped poppet is preferred because it facilitates the movement of the pressurized air therepast, during operations of the system.
[0027] FIG. 3 provides a vertical section through the center of the check valve 1 , and as noted, its poppet 8 is in continuous contact with a valve seat 9 formed of its housing 6 . This is a molded gasket seat.
[0028] It can also be seen that the housing 6 is formed of two halves, as noted at 10 and 11 , and these are fastened into closure, with a sealing O ring 12 provided around its circumference, and secured by means of a plurality of fasteners 13 as to be noted. These two halves form a widened bell housing that accommodates air flow therethrough.
[0029] It is to be noted that the housing has an outwardly bulging internal contour 14 , forming the bell, so that when the poppet 8 is unseated, there is still ample volumetric capacity for the pressurized air to pass around the poppet, through the housing, an out of the check valve and into the air line 2 , so that no pressure reduction of any significance occurs. Hence, generally, the volumetric capacity of the internally convexed housing, as noted at 14 , is at least equal to the volumetric capacity of the air flow line 2 , so that air under pressure can pass from the air line, into and through the housing 6 , and out the air line 2 at the outlet side, without any pressure reduction, or obstruction to the flow of the pressurized air therethrough.
[0030] As can also be seen in FIG. 3 , there is a bushing 15 that is mounted within the housing, as will be subsequently described, and the bushing 15 as a channel 16 provided therethrough, with a shoulder 17 furnished at its downstream side. The stem 18 of the poppet 8 locates within the channel 16 , and the stem includes another shoulder 19 against which a compression spring 20 biases, against both of the shoulders 17 and 19 , and generally forces the poppet 8 into closure, against its valve seat 9 , in the manner is shown in FIG. 3 , so as to constantly bias the poppet into closure within the check valve, when the system is shut off.
[0031] But, as can be seen in FIG. 4 , when the poppet 8 is unseated from its valve seat 9 , as when air under pressure is forced through the check valve 1 , there is yet that ample area surrounding the poppet, as previously explained, along the internal contour 14 of the housing, to allow for the air under pressure to pass there around, without any significant pressure drop.
[0032] What is significant about this invention, is that the biasing spring 20 is always arranged between the shoulders 17 and 19 of their respective bushing and valve stem, and that spring remains totally enclosed and encapsulated within the channel 16 , of the valve, so that when the spring fatigues, and breaks because of excessive usage, or long term usage, the broken parts of the spring remain within the channel 20 , and cannot be discharged there from, to become entrained within the flow of the passing air, or eventually get into the granular material being conveyed, in the bulk material flow line.
[0033] FIG. 5 shows how the bushing 15 is structurally supported within the valve housing 6 , through the use of at least a pair of integral ribs 21 as to be noted. The ribs have a slight arcuate contour to them, so that as air passes by these mounting ribs, the ribs have a tendency to force the air into a slightly swirling pattern, which helps facilitate the movement of the air, and the forceful conveyance of any granular material, downstream, to enter into and be conveyed to the location of unloading. In addition, these ribs may have a slight contour to them, such as tapering from their upstream to their downstream side, to allow for the air to be separated as it passes the mounting ribs, with little resistance, other than to initiate the air into a more swirling pattern, as it bypasses the mounting ribs and exits from the check valve into the downstream air line 2 .
[0034] FIG. 6 provides an enlarged view of the bushing 15 , part of its ribs 21 , and the location of the bushing channel 16 , as to be noted. The location of the reduced size of valve stem 22 , integral with the valve stem 18 of the poppet, can be seen supporting the compression spring 20 and maintaining the spring located totally within the bushing channel 16 , as previously reviewed. Further bearings 23 are provided at each end of the bushing, and embrace the valve stem therein, for sliding movement, as when the poppet moves from its valve seat, as noted in FIG. 3 , to its unseated position, as noted in FIG. 4 , and thereby prevents any part of a broken spring escaping from the channel 16 , in the event that occurs. It can be seen that the extensions upstream and downstream of the bushing 15 support the bearings 23 , and regardless whether the valve stem shifts into closure, as in FIG. 3 , the channel 16 is always closed off, to prevent discharge of any part of the spring, in the event that it breaks. Likewise, when the spring is subjected to complete compression, as noted in FIG. 4 , as when the poppet is forced by the air pressure to unseat from its valve seat 9 , the spring still remains closed within the bushing chamber 16 , as to be noted. This is due to the integral extension of the bushing 15 , that extends integrally upstream, and downstream, from their inherent ribs 21 , during manipulation of the check valve between open and closed conditions. It also checks the extent of opening of the valve and its poppet.
[0035] It needs to be reviewed that the check valve of this design has performed very satisfactory, and through testing, when compared to flapper valves or check valves of the prior art, this invention performs multiple times better than the prior art valves. For example, when the check valve of this invention was subject to testing, it was tested for 135,000 cycles, without any part of the valve breaking, and with the spring remaining totally sealed within its chamber without any fatigue or fracture. But, when prior art style of valves where tested, one prior art valve, of the flapper type, and which incorporated the tension type of torsion spring, that was exposed to the exterior of the valve, the tested valve failed at 45,000 cycles, and emptied its broken spring parts into the flow of the passing air. Another style of flapper valve, with exposed springs underwent the same testing, failed with broken springs at 46,000 cycles. Thus, it could be seen that the improved check valve of this invention has a functional life cycle almost three times the failure cycle of the prior art style of valves, whether they be of the flapper valve type, or a check valve that has exposed springs. And, the broken spring parts of the prior art valves caused contamination.
[0036] It may also be common that during usage it normally takes approximately 15 lbs. of air pressure, or 15 PSI of back pressure, to open these valves, and allow the pressurized air to routinely pass through the check valve, and on to the granular material flow line, to induce and maintain flow of the dry bulk material from their flow line during unloading or conveying to another location for either usage or storage.
[0037] In the preferred embodiment of the current invention, usually, when the poppet is open, due to the internal contour of its supportive housing, there is provided approximately a 14.1 square inch minimal flow area around the poppet when it is fully opened, to allow pressurized air to flow therethrough. In addition, there is an approximate 8.6 square inch minimum flow area around the bushing boss, to allow the pressurized air to pass thereby. There is also a minimum 18.1 square inch minimum flow area around the supporting integral fins, for the bushing, to allow air to pass thereby. This type of a check valve normally is used in a 3 inch schedule 10 pipe and in which the check valve of this invention is typically installed and a 3 inch pipe normally provides a flow area of 8.3 square inches, in its dimension.
[0038] Variations or modifications to the subject matter of this invention may occur to those skilled in the art upon review of the development as provided herein. Such variations, if within the spirit of this invention, are intended to be encompassed within the scope of any claims to patent protection issuing hereon. The description of the preferred embodiment in this application, and its depiction in the drawings, are primarily set forth for illustrative purposes only. | A check valve for use in an air flow line to convey pressurized air to unload a tank trailer, railroad car, or other conveying facility. It includes a housing, having a valve seat, a check valve for seating upon the valve seat, a bushing holding the valve stem for the check valve, with the bushing having a channel therein, through which the valve stem locates, and contains a spring therein that is totally encapsulated within the bushing chamber, during usage. The housing is internally contoured to enhance the flow of pressurized air therethrough. | 8 |
NOTICE OF COPYRIGHTS AND TRADE DRESS
A portion of the disclosure of this patent document contains material which is subject to copyright protection. This patent document may show and/or describe matter which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by any one of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to moldings for architectural concrete forming.
2. Description of Related Art
Many buildings are formed from concrete panels or elements. The concrete tilt-up is one example of such a structure. To make a concrete panel or element, a form is prepared and concrete is poured into the form. After the concrete sets, the form may be removed.
To enhance the aesthetic aspects of concrete panels and elements, the forms may include architectural molding. These moldings are typically made from solid wood (e.g., clear pine), and sometimes extruded plastic. Architectural molding may be manufactured on-site or prefabricated. At the job site, the architectural molding is typically cut to size when needed and added to the general form. The architectural molding is typically nailed to other parts the form.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevated perspective view of an architectural molding in accordance with the invention.
FIG. 2 is an apparatus for manufacturing an architectural molding for concrete forming in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and methods of the present invention.
Referring now to FIG. 1 , there is shown an elevated perspective view of an architectural molding 100 in accordance with the invention. The architectural molding 100 may be a reveal, rustication, detail, chamfer or other architectural molding used in concrete forms. Architectural molding is characterized by structural strength, which allows it to withstand the pressure of uncured concrete that has been poured into a form.
Often, after the architectural molding is delivered to a job site, the architectural molding is stored in the open until used. The architectural molding is therefore exposed to the elements and may be degraded by such exposure. For example, some materials such as fiber board, have been found to warp or otherwise change shape when exposed to moisture. The moisture may be present from rain, dew, sprinklers or other environmental conditions. As explained below, the architectural molding of the invention may be manufactured to withstand such degradation.
Architectural molding may have other qualities. For example, to produce a smooth concrete surface, the architectural molding have a smooth surface which faces the concrete. If a textured concrete surface is desired, it may be obtained from architectural molding having a corresponding textured surface which faces the concrete.
As used herein, “concrete” means a pourable substance which sets into a hard, strong building material. Concrete may be made by mixing a cementing material (such as portland cement) and a mineral aggregate (such as sand and gravel) with sufficient water to cause the cement to set and bind the entire mass.
The architectural molding 100 comprises a stock to which a coating has been applied. The stock may have one or more surfaces 110 , 120 , 130 which will, when the architectural molding 100 is used, will face the poured concrete. These surfaces 110 , 120 , 130 will be referred to herein as “exposed” surfaces. In addition to the exposed surfaces 110 , 120 , 130 , the stock 110 may define one or more unexposed surfaces 140 , 160 . There may also be partially exposed surfaces. Altogether, the exposed, unexposed and partially exposed surfaces make up an entire outside surface of the architectural molding.
The stock may comprise a material such as medium density fiber board (MDF). MDF and many other materials are porous and water absorptive. These materials are sponge-like, and will absorb water which impinges on their surface. Depending on their manufacture and inherent properties, these materials have an entire exposed surface, a substantial portion of the exposed surface, or a small portion of the exposed surface which is porous.
The stock may also comprise solid wood, wood fibers, particle board, extruded plastics, metals, composites and other materials which are hard and strong enough for use in concrete forms. The stock may comprise a single material or a combination of materials, and the combinations may be homogenous or not. The stock may include a binder for binding constituents.
The stock may have a predefined shape or cross-section adapted and especially suited for use in architectural molding. For example, chamfer generally has a triangular cross-section.
The architectural molding 100 may include a coating which substantially evenly covers the exposed surface of the stock. The coating may overcome the water absorptive and/or porous qualities of the stock. The coating may be water proof or water resistant. The coating may include or be a coloring agent. As used herein, “coloring agent” refers to a pigment, dye, paint or other substance which will give the stock a color different from its appearance without the coloring agent. The coloring agent may be visible upon application or may rendered visible by drying or some other process. The coating may include wax, oil, plastics, and/or resins. Color may be useful for making the architectural molding 100 easily identifiable as to its source, quality, type or otherwise. Since architectural molding is generally not visible when installed in a concrete form, and the concrete form is temporary, color may have no aesthetic benefits.
The coating may comprise one or more layers. Extra layers may be desired or necessary to achieve evenness, or so that separate materials may be applied, such as a water proofer in one layer and a coloring agent in a second layer.
The coating may maintain or alter the surface quality of the stock. For example, an otherwise smooth exposed surface may be coated to have a texture. The texture may be even, grained or patterned, for example. Alternatively, the exposed surface of a stock may be coated to be smooth—even smoother than the stock itself. Other qualities may include slippery or waxy.
The coated architectural molding 100 may be used as part of a concrete form.
Referring now to FIG. 2 there is shown an apparatus 200 for manufacturing an architectural molding for concrete forming in accordance with the invention. The apparatus comprises an application chamber 210 , a dry chamber 220 and a conveyor 230 . The apparatus will be described in conjunction with a method of manufacturing an architectural molding for concrete forming in accordance with the invention.
The method begins with stock 240 . As a preliminary step, the stock may be shaped to be suitable as, for example, chamfer or reveal. This shaping may through cutting, molding or other techniques.
In one step, stock 240 is moved on the conveyor 230 into the application chamber 210 . The conveyor 230 may be, for example, a belt, web or mesh. The conveyor 230 may be a continuous loop. Alternatively, the conveyor 230 may comprise a series of rollers across which the stock 240 slides, and the conveyor 230 may include an apparatus for pushing the stock 240 along the rollers.
In another step, in the application chamber 210 , a coating is mechanically applied to the stock 240 . The application chamber 210 may include one or more spray heads 211 for applying the coating housed within an enclosure 212 . The spray heads 211 may be located above and below the conveyor to provide single-pass coverage, and the spray heads may move to provide coverage. The coating may be applied through other methods, such as dipping, or passing the stock 240 through a stream. The coating may be applied as a liquid, a solid, a slurry, a colloid, a vapor, a gas or other form. The coating may be prepared on-site, such as by mixing a water sealant with a coloring agent.
Through mechanical application, a substantially even application of the coating may be obtained. It has been found that manual application provides unsatisfactory results because of missed spots or over-application. In addition, some coating materials do not lend themselves to manual application due to their hazardous nature. Because of the controls afforded through mechanical application, the coating may be applied to just the exposed surface of the stock, or to the entire outside surface of the stock.
After the application step, the now-coated stock 250 may be moved out of the application chamber 210 and into a dry chamber 220 . The dry chamber 220 may include one or more curing or drying lamps 221 housed within an enclosure 222 . Within the dry chamber 220 , the coating may cure, set, dry or otherwise change. The form change may be made possible or controlled by use of light, heat, radiation, catalysts, pressure, etc. For example, a water sealant may set, or a coloring agent may be rendered visible. The coated stock 250 may then be moved out of the drying changer as finished architectural molding.
The architectural molding of the invention may have a wide range of environmental usability, or may be tailored to perform well in certain environmental conditions. For example, the coating may be suitable for temperatures between 0 and 115° F.
The entire process of manufacturing an architectural molding for concrete forming may be automated. Alternatively, selected steps may be automated. For example, the steps of moving the stock into the application chamber 210 , applying the coating and moving the stock out of the application chamber 210 may be fully automatic.
Although shown as separate chambers, the application chamber 210 and dry chamber 220 may be contiguous or continuous. Where several layers are to be applied, for example, there may be several application chambers and several dry chambers, and the type of chambers may alternate. In addition, the application chamber 210 and the dry chamber 220 may include or omit the enclosures 212 , 222 .
Although exemplary embodiments of the present invention have been shown and described, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit of the present invention. All such changes, modifications and alterations should therefore be seen as within the scope of the present invention. | There is disclosed a molding for architectural concrete forming. The molding may be manufactured by applying a coating to a stock. The architectural molding may be rendered better-suited to certain environmental conditions or for certain uses by applying appropriate coatings. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The application is a continuation application of U.S. application Ser. No. 13/369,876, filed on Feb. 9, 2012, which claims priority under 35 U.S.C.§119(e) to U.S. Provisional Application 61/441,624, filed Feb. 10, 2011. The contents of these applications are incorporated herein by reference in their entirety.
[0002] The instant application contains a Sequence Listing which has been submitted via EFS-Web and is hereby incorporated by reference in its entirety. Said ASCII copy, created on Mar. 15, 2012 is named 99300302.txt and is 2,999 bytes in size.
FIELD OF THE INVENTION
[0003] The present invention relates to methods of diagnosing and treating human cancers.
BACKGROUND OF THE INVENTION
[0004] The following discussion of the background of the invention is merely provided to aid the reader in understanding the invention and is not admitted to describe or constitute prior art to the present invention.
[0005] There is considerable interest in understanding the function of RNA transcripts that do not code for proteins in eukaryotic cells. As evidenced by cDNA cloning projects and genomic tiling arrays, more than 90% of the human genome undergoes transcription but does not code for proteins. These transcriptional products are referred to as non-protein coding RNAs (ncRNAs). A variety of ncRNA transcripts, such as ribosomal RNAs, transfer RNAs, and spliceosomal RNAs, are essential for cell function. Similarly, a large number of short ncRNAs such as micro-RNAs (miRNAs), endogenous short interfering RNAs (siRNAs), PIWI-interacting RNAs (piRNAs) and small nucleolar RNAs (snoRNAs) are also known to play important regulatory roles in eukaryotic cells. Recent studies have demonstrated a group of long ncRNA (lncRNA) transcripts that exhibit cell type-specific expression and localize into specific subcellular compartments. lncRNAs are also known to play an important roles during cellular development and differentiation supporting the view that they have been selected during the evolutionary process.
[0006] LncRNAs appear to have many different functions. In many cases, they seem to play a role in regulating the activity or localization of proteins, or serve as organizational frameworks for subcellular structures. In other cases, lncRNAs are processed to yield multiple small RNAs or they may modulate how other RNAs are processed. Interestingly, lncRNAs can influence the expression of specific target proteins at specific genomic loci, modulate the activity of protein binding partners, direct chromatin-modifying complexes to their sites of action, and are post-transcriptionally processed to produce numerous 5′-capped small RNAs. Epigenetic pathways can also regulate the differential expression of lncRNAs. lncRNAs are misregulated in various diseases, including ischaemia, heart disease, Alzheimer's disease, psoriasis, and spinocerebellar ataxia type 8. This misregulation has also been shown in various types of cancers, such as breast cancer, colon cancer, prostate cancer, hepatocellular carcinoma and leukemia. One such lncRNA, DD3 (also known as PCA3), is listed as a specific prostate cancer biomarker. Recent studies have revealed the contribution of ncRNAs as proto-oncogenes, e.g. GAGE6, as tumor suppressor genes in tumorigenesis, and as drivers of metastatic transformation, e.g. HOTAIR in breast cancer.
SUMMARY OF THE INVENTION
[0007] The present invention is based on the discovery of the correlation between long non-coding RNA SPRY-IT1 and human cancers, in particular melanoma.
[0008] In one aspect, the present invention provides a method for diagnosing melanoma in a subject suspected of having melanoma comprising: (i) assessing the expression level of SPRY4-IT1 in a biological sample obtained from the subject; (ii) comparing the expression level of SPRY4-IT1 in the sample to the a reference expression level derived from the expression level of SPRY4-IT1 in samples obtained from subjects diagnosed as not having melanoma; and (iii) identifying the subject as having melanoma when the expression level of SPRY4-IT1 in the sample is greater than the reference expression level or identifying the subject as not having melanoma when the expression level of SPRY4-IT1 in the sample is not greater than the reference expression level. In some embodiments, the biological sample may comprise skin, skin epidermis, or melanocytes.
[0009] In further embodiments, the expression level of SPRY4-IT1 is assessed by evaluating the amount of SPRY4-IT1 mRNA in the biological sample. The evaluation of the SPRY4-IT1 mRNA may, in some embodiments, comprise reverse transcriptase PCR (RT-PCR). The evaluation may further comprise array hybridization, wherein the array comprises an immobilized nucleic acid probe that specifically hybridizes SPRY4-IT1 mRNA, SPRY4-IT1 cDNA, or complements thereof. In still further embodiments, the method may further comprise assessing a SPRY4-IT1 target and identifying the subject as having melanoma when the expression level of both SPRY4-IT1 and the SPRY4-IT1 target is increased. In such cases, the SPRY4-IT1 target may be selected from the group consisting of Ki-67, MCM2, MCM3, MCM4, MCM5, CDK1, CDC20, XIAP, Hsp60, Hsp70, and Livin. In still further embodiments, the method may comprise assessing a SPRY4-IT1 target and identifying the subject as having melanoma when the expression level of SPRY4-IT1 is increased and the expression level of the SPRY4-IT1 target is decreased. In such cases, the SPRY4-IT1 target may be selected from the group consisting of TNFRSF25, DPP-IV, CD26, and Trail R2/DR5.
[0010] In another aspect, the present invention provides a method for determining the risk of a subject for developing melanoma comprising: (i) assessing the expression level of SPRY4-IT1 in a biological sample obtained from the subject; (ii) comparing the expression level of SPRY4-IT1 in the sample to the a reference expression level derived from the expression level of SPRY4-IT1 in samples obtained from subjects diagnosed as not having melanoma; and (iii) identifying the subject as having increased risk of developing melanoma when the expression level of SPRY4-IT1 in the sample is greater than the reference expression level or identifying the subject as not having an increased risk of melanoma when the expression level of SPRY4-IT1 in the sample is not greater than the reference expression level. In some embodiments, the biological sample may comprise skin, skin epidermis, or melanocytes.
[0011] In further embodiments, the expression level of SPRY4-IT1 is assessed by evaluating the amount of SPRY4-IT1 mRNA in the biological sample. The evaluation of the SPRY4-IT1 mRNA may, in some embodiments, comprise reverse transcriptase PCR (RT-PCR). The evaluation may further comprise array hybridization, wherein the array comprises an immobilized nucleic acid probe that specifically hybridizes SPRY4-IT1 mRNA, SPRY4-IT1 cDNA, or complements thereof. In still further embodiments, the method may further comprise assessing a SPRY4-IT1 target and identifying the subject as having melanoma when the expression level of both SPRY4-IT1 and the SPRY4-IT1 target is increased. In such cases, the SPRY4-IT1 target may be selected from the group consisting of Ki-67, MCM2, MCM3, MCM4, MCM5, CDK1, CDC20, XIAP, Hsp60, Hsp70, and Livin. In still further embodiments, the method may comprise assessing a SPRY4-IT1 target and identifying the subject as having melanoma when the expression level of SPRY4-IT1 is increased and the expression level of the SPRY4-IT1 target is decreased. In such cases, the SPRY4-IT1 target may be selected from the group consisting of TNFRSF25, DPP-IV, CD26, and Trail R2/DR5.
[0012] In yet another aspect, the present invention provides a method for treating a patient diagnosed as having melanoma comprising administering to the patient an effective amount of a therapeutic agent that reduces SPRY4-IT1 expression. In some embodiments, the SPRY4-IT1 may be reduced in the melanoma cells, and in further embodiments the reduction may be by at least 10%, at least 50%, or at least 90%.
[0013] In still another aspect, the present invention provides a method for diagnosing prostate cancer in a subject suspected of having prostate cancer comprising: (i) assessing the expression level of SPRY4-IT1 in a biological sample obtained from the subject; (ii) comparing the expression level of SPRY4-IT1 in the sample to the a reference expression level derived from the expression level of SPRY4-IT1 in samples obtained from subjects diagnosed as not having prostate cancer; and (iii) identifying the subject as having prostate cancer when the expression level of SPRY4-IT1 in the sample is greater than the reference expression level or identifying the subject as not having prostate cancer when the expression level of SPRY4-IT1 in the sample is not greater than the reference expression level.
[0014] In yet another aspect, the present invention provides a method for determining the risk of a subject for developing prostate cancer comprising: (i) assessing the expression level of SPRY4-IT1 in a biological sample obtained from the subject; (ii) comparing the expression level of SPRY4-IT1 in the sample to the a reference expression level derived from the expression level of SPRY4-IT1 in samples obtained from subjects diagnosed as not having prostate cancer; and (iii) identifying the subject as having increased risk of developing prostate cancer when the expression level of SPRY4-IT1 in the sample is greater than the reference expression level or identifying the subject as not having an increased risk of prostate cancer when the expression level of SPRY4-IT1 in the sample is not greater than the reference expression level.
[0015] In further embodiments of either of the two preceding aspects, the expression level of SPRY4-IT1 is assessed by evaluating the amount of SPRY4-IT1 mRNA in the biological sample. The evaluation of the SPRY4-IT1 mRNA may, in some embodiments, comprise reverse transcriptase PCR (RT-PCR). The evaluation may further comprise array hybridization, wherein the array comprises an immobilized nucleic acid probe that specifically hybridizes SPRY4-IT1 mRNA, SPRY4-IT1 cDNA, or complements thereof. In still further embodiments, the method may further comprise assessing a SPRY4-IT1 target and identifying the subject as having melanoma when the expression level of both SPRY4-IT1 and the SPRY4-IT1 target is increased. In such cases, the SPRY4-IT1 target may be selected from the group consisting of Ki-67, MCM2, MCM3, MCM4, MCM5, CDK1, CDC20, XIAP, Hsp60, Hsp70, and Livin. In still further embodiments, the method may comprise assessing a SPRY4-IT1 target and identifying the subject as having melanoma when the expression level of SPRY4-IT1 is increased and the expression level of the SPRY4-IT1 target is decreased. In such cases, the SPRY4-IT1 target may be selected from the group consisting of TNFRSF25, DPP-IV, CD26, and Trail R2/DR5.
[0016] In yet another aspect, the present invention provides a method for treating a patient diagnosed as having prostate cancer comprising administering to the patient an effective amount of a therapeutic agent that reduces SPRY4-IT1 expression. In some embodiments, the SPRY4-IT1 may be reduced in the melanoma cells, and in further embodiments the reduction may be by at least 50%.
[0017] The therapeutic agent may be, in further embodiments, an siRNA or an anti-sense nucleic acid, or may comprise a nucleic acid comprising the sequence of SEQ ID NO: 2. The nucleic acid may further be encoded in a vector, which may be a viral vector. The therapeutic agent may additionally be contained within a liposome.
[0018] In still a further embodiment, the present invention provides a method for identifying therapeutic agents useful for treating melanoma comprising: (i) providing cells expressing SPRY4-IT1; (ii) treating the cells with a candidate compound; (iii) measuring the expression level of SPRY4-IT1 in the cells after treatment with the candidate compound; and (iv) identifying the candidate compound as useful for treating melanoma when the expression level of SPRY4-IT1 is reduced in the cells relative to the expression level of SPRY4-IT1 in the cells prior to treatment with the candidate compound. In some embodiments, the cells—which may be or be derived from human cells—may comprise melanocytes or melanoma cells.
[0019] In further embodiments, the expression level of SPRY4-IT1 is assessed by evaluating the amount of SPRY4-IT1 mRNA in the biological sample. The evaluation of the SPRY4-IT1 mRNA may, in some embodiments, comprise reverse transcriptase PCR (RT-PCR). The evaluation may further comprise array hybridization, wherein the array comprises an immobilized nucleic acid probe that specifically hybridizes SPRY4-IT1 mRNA, SPRY4-IT1 cDNA, or complements thereof.
[0020] In another aspect, a method is provided for diagnosing a cancer, the cells of which ectopically express SPRY4-IT1, in a subject suspected of having such cancer, said method comprising: (i) assessing the expression level of SPRY4-IT1 in a biological sample obtained from the subject; (ii) comparing the expression level of SPRY4-IT1 in the sample to the a reference expression level derived from the expression level of SPRY4-IT1 in samples obtained from subjects diagnosed as not having cancer; and (iii) identifying the subject as having cancer when the expression level of SPRY4-IT1 in the sample is greater than the reference expression level or identifying the subject as not having cancer when the expression level of SPRY4-IT1 in the sample is not greater than the reference expression level.
[0021] In yet another aspect, a method is provided for determining the risk of a subject for developing a cancer, the cells of which ectopically express SPRY4-IT1, in a subject suspected of being likely to develop such cancer, said method comprising: (i) assessing the expression level of SPRY4-IT1 in a biological sample obtained from the subject; (ii) comparing the expression level of SPRY4-IT1 in the sample to the a reference expression level derived from the expression level of SPRY4-IT1 in samples obtained from subjects diagnosed as not having cancer; and (iii) identifying the subject as having increased risk of developing cancer when the expression level of SPRY4-IT1 in the sample is greater than the reference expression level or identifying the subject as not having an increased risk of cancer when the expression level of SPRY4-IT1 in the sample is not greater than the reference expression level.
[0022] In still another aspect, a method is provided for treating a patient diagnosed as having a cancer, the cells of which ectopically express SPRY4-IT1, said method comprising administering to the patient an effective amount of a therapeutic agent that reduces SPRY4-IT1 expression. In some embodiments, the therapeutic agent may further act to downregulate expression of Ki-67, MCM2, CDK1, CDC20, XIAP, Livin, Hsp60, Hsp70, MCM3, MCM4, or MCM5, or upregulate expression of a gene selected from the group consisting of TNFRSF25, DPP-IV, or Trail R2/DR5. In embodiments of any of the aspects above, the cancer cells may be located in a tumor in an organ selected from the group consisting of the skin, adrenal gland, lung, stomach, testis, prostate, and uterus.
[0023] As used herein, the term “nucleic acid molecule” or “nucleic acid” refer to an oligonucleotide, nucleotide or polynucleotide. A nucleic acid molecule may include deoxyribonucleotides, ribonucleotides, modified nucleotides or nucleotide analogs in any combination.
[0024] As used herein, the term “nucleotide” refers to a chemical moiety having a sugar (modified, unmodified, or an analog thereof), a nucleotide base (modified, unmodified, or an analog thereof), and a phosphate group (modified, unmodified, or an analog thereof). Nucleotides include deoxyribonucleotides, ribonucleotides, and modified nucleotide analogs including, for example, locked nucleic acids (“LNAs”), peptide nucleic acids (“PNAs”), L-nucleotides, ethylene-bridged nucleic acids (“ENAs”), arabinoside, and nucleotide analogs (including abasic nucleotides).
[0025] As used herein, the term “short interfering nucleic acid” or “siNA” refers to any nucleic acid molecule capable of down regulating (i.e., inhibiting) gene expression in a mammalian cells (preferably a human cell). siNA includes without limitation nucleic acid molecules that are capable of mediating sequence specific RNAi, for example short interfering RNA (siRNA), double-stranded RNA (dsRNA), micro-RNA (miRNA), and short hairpin RNA (shRNA).
[0026] As used herein, the term “sense region” refers to a nucleotide sequence of a siNA molecule complementary (partially or fully) to an antisense region of the siNA molecule. Optionally, the sense strand of a siNA molecule may also include additional nucleotides not complementary to the antisense region of the siNA molecule.
[0027] As used herein, the term “ectopic expression” refers to the occurrence of gene expression or the occurrence of a level of gene expression in a tissue in which it is not generally expressed, or not generally expressed at such a level.
[0028] As used herein, the term “SPRY4-IT1 target” refers to a gene coding for a functional biomolecule, i.e., a protein, which is addressed and controlled by SPRY4-IT1. For example, SPRY4-IT1 targets may include, although are not limited to, Ki-67, TNFRSF25, DPP-IV, CD26, MCM2, CDK1, CDC20, XIAP, Hsp60, Hsp70, Trail R2/DR5, MCM3, MCM4, MCM5, and Livin.
[0029] As used herein, the term “antisense region” refers to a nucleotide sequence of a siNA molecule complementary (partially or fully) to a target nucleic acid sequence. Optionally, the antisense strand of a siNA molecule may include additional nucleotides not complementary to the sense region of the siNA molecule.
[0030] As used herein, the term “duplex region” refers to the region in two complementary or substantially complementary oligonucleotides that form base pairs with one another that allows for a duplex between oligonucleotide strands that are complementary or substantially complementary. For example, an oligonucleotide strand having 21 nucleotide units can base pair with another oligonucleotide of 21 nucleotide units, yet only 19 bases on each strand are complementary or substantially complementary, such that the “duplex region” consists of 19 base pairs. The remaining base pairs may, for example, exist as 5′ and/or 3′ overhangs.
[0031] An “abasic nucleotide” conforms to the general requirements of a nucleotide in that it contains a ribose or deoxyribose sugar and a phosphate but, unlike a normal nucleotide, it lacks a base (i.e., lacks an adenine, guanine, thymine, cytosine, or uracil). Abasic deoxyribose moieties include, for example, abasic deoxyribose-3′-phosphate; 1,2-dideoxy-D-ribofuranose-3-phosphate; 1,4-anhydro-2-deoxy-D-ribitol-3-phosphate.
[0032] As used herein, the term “inhibit”, “down-regulate”, or “reduce,” with respect to gene expression, means that the level of RNA molecules encoding one or more proteins or protein subunits (e.g., mRNA) is reduced below that observed in the absence of the inhibitor. Expression may be reduced by at least 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5% or below the expression level observed in the absence of the inhibitor.
BRIEF DESCRIPTION OF THE FIGURES
[0033] FIG. 1A is a genome browser depiction of the SPRY4 locus; 1 B and 1 C are representations of expression level data of SPRY4-IT1; and 1 D is a computational prediction of the secondary structure of SPRY4-IT1.
[0034] FIG. 2A 2 B are bar graphs depicting the expression level of SPRY4-IT1 in 20 human tissues relative to RPLO and SPRY4.1, respectively.
[0035] FIG. FIGS. 3A-3D are bar graphs showing expression of SPRY4-IT1 expression in melanoma patients by location of sample: in primary, nodal metastasis, regional metastasis, and distant metastasis, respectively.
[0036] FIGS. 4A and 4B are bar graphs showing expression of SPRY4-IT1 following knockdown by siRNA; 4 C is a photograph of the gel confirming the occurrence of the knockdown; and 4 D is a series of photographs showing localization of SPRY4-IT1 in melanocytes.
[0037] FIGS. 5A and 5B are graphs showing viability of melanoma cells; 5 C shows the results of flow cytometry after SPRY4-IT1 knockdown; 5 D is a graph showing invasion potential, and 5 E is a series of photographs of invading cells.
[0038] FIG. 6 is a data cluster of the microarray data from normal and melanoma patient skin samples.
[0039] FIG. 7A-7D is cDNA sequencing data illustrating expression levels of four melanoma-specific lncRNAs.
[0040] FIG. 8 is a graph of qRT-PCR results for SPRY4-IT1 expression levels in four types of cells.
[0041] FIG. 9A-9D is sequencing data showing mapped tag densities for SPRY1, SPRY2, SPRY3, and SPRY4 loci, respectively.
[0042] FIG. 10 is a bar graph showing quantitative mRNA levels of SPRY4 in melanoma and melanocytes.
[0043] FIG. 11A-11C are bar graphs showing the expression of the two SPRY4 alternate mRNA isoforms in 20 normal human tissues.
[0044] FIG. 12A-12D are bar graphs showing relative expression of SPRY4-IN-1 to SPRY4.2 in primary, nodal metastasis, regional metastasis, and distant metastasis samples, respectively.
[0045] FIG. 13 is a bar graph showing SPRY4 expression in a dose-dependent knockdown of SPRY4-IT1 in melanoma.
[0046] FIG. 14 is the cDNA nucleotide sequence for SPRY4-IT1 (GenBank Accession No. AK024556; SEQ ID NO: 1).
[0047] FIG. 15 is a series of photographs of melanocytes infected with control lenti-vector and lenti-SPRY4-IT1 vector stained with texas red, GFP, DAPI, and Merged. As shown, SPRY4-IT1 is primarily transported into the cytoplasm in cells engineered to ectopically express SPRY4-IT1.
[0048] FIG. 16 is a line graph showing activation of melanocyte proliferation by infection with SPRY4-IT1 over time in control lenti-vector infected cells and lenti-SPRY4-IT1-infected cells.
[0049] FIG. 17 is a series of photographs showing proliferation of cells engineered to ectopically express SPRY4-IT1 as compared to control cells.
[0050] FIG. 18 is a bar graph showing the relative mRNA levels of target genes of SPRY4-IT1 as expressed in qRT-PCR.
[0051] FIG. 19 is a diagram illustrating the cloning strategy for the SPRY4-IT1 upstream sequence and entire SPRY4 intron 1.
[0052] FIG. 20 is a bar graph showing SPRY4-IT1 putative promoter expression via luciferase expression containing the putative promoter construct (pcDNA/Luc/SP-IT1) and controls.
[0053] FIG. 21 is a line graph demonstrating the rate of decay of RNA of SPRY4-IT1 compared to its host gene after treatment with α-Amanitin.
[0054] FIG. 22A-22F is a series of bar graphs showing the expression of SPRY4-IT1 in tumor cells from various organs 22 A, the adrenal gland 22 C, the lung 22 E and the log 2 expression of the same 22 B, 22 D, 22 F.
[0055] FIG. 23A-23F is a series of bar graphs showing the expression of SPRY4-IT1 in tumor cells from the stomach 23 A, testis 23 C, and uterus 23 E, and the log 2 expression of the same 23 B, 23 D, 23 F
[0056] FIG. 24 is a series of photographs showing expression of Ki-67 in melanocytes expressing SPRY4-IT1 as compared to cells expressing empty vector.
DETAILED DESCRIPTION
[0057] The present invention relates generally to identifying and characterizing long non-coding RNAs (“lncRNAs”) that are differentially expressed in cancer cells, particularly in melanoma, as compared to melanocytes or normal skin. In particular, one such lncRNA, SPRY4-IT1, located in the intronic region of the SPRY4 gene, has been shown to be upregulated in melanoma cells and in tumor cells found in the stomach, the adrenal gland, the uterus, the testis, and the lung. SPRY4 is an inhibitor of the receptor-transduced mitogen-activated protein kinase (MAPK) signaling pathway that functions upstream of RAS activation and impairs the formation of active GTP-RAS. Downregulation of the expression of SPRY4-IT1 results in defects in cell growth, differentiation and elevated rates of apoptosis in melanoma cells.
[0058] The identification of cancer-associated lncRNAs and the investigation of their molecular and biological functions aids in understanding the molecular etiology of cancer and its progression. Data provided herein demonstrates that a number of lncRNAs are differentially expressed in melanoma cell lines in comparison to melanocytes and keratinocyte controls. One of these lncRNAs, SPRY4-IT1 (Genbank accession ID AK024556), is derived from an intron of the SPRY4 gene and is predicted to contain several long hairpins in its secondary structure. RNA-FISH analysis demonstrates that SPRY4-IT1 is predominantly accumulated in melanoma cell cytoplasm, and SPRY4-IT1 knock-down by stealth siRNAi results in defects in cell growth, differentiation and higher rates of apoptosis in melanoma cell lines. Differential expression of both SPRY4 and SPRY4-IT1 was also detected in vivo, in 30 distinct patient samples, classified as primary in situ, regional metastatic, distant metastatic, and nodal metastatic melanoma. The elevated expression of SPRY4-IT1 in melanoma cells compared to melanocytes, its accumulation in cell cytoplasm, and effects on cell dynamics demonstrates that SPRY4-IT1 plays an important role in human melanoma.
[0059] Sprouty (SPRY) is a Ras/Erk inhibitor protein and there are four SPRY genes (SPRY1, SPRY2, SPRY3 and SPRY4) in human. SPRY4 which is the host gene of lncRNA SPRY4-IT1, occurs in two alternately spliced isoforms, termed SPRY4.1 and SPRY4.2, the latter of which retains an additional exon that results in translation initiating from an alternate start codon. To better understand where SPRY4 functions and the relative expression of the two isoforms, qRT-PCR was used to measure the expression of SPRY4.1 and SPRY4.2 across 20 human tissues. Differential expression levels of these isoforms indicate that the existence of an isoform specific regulatory mechanisms in melanomas and normal human tissues. Deep-sequencing results show that SPRY1 and SPRY3 have little or no expression in both melanoma and melanocytes, but SPRY2 and SPRY4 are highly expressed in melanoma cells compared to melanocytes. Preliminary results indicate, however, that SPRY-IT1 regulation is independent of its master gene, SPRY4.
[0060] SPRY4-IT1 is expressed in melanoma cells but not in melanocytes. The elevated expression of SPRY4-IT1 in melanoma cells compared to melanocytes, its accumulation in cell cytoplasm, and effects on cell dynamics suggest that SPRY4-IT1 plays an important role in melanoma development and is an early biomarker and a key regulator for melanoma pathogenesis in human.
[0061] SPRY4-IT1 is also shown herein to be expressed in tumor cells of organs other than the skin, including, for example, adrenal gland, lung, stomach, testis, prostate, and uterus.
[0062] Several targets of SPRY4-IT1 are identified herein. Those targets include the cell proliferation protein Ki-67, the pro-apoptotic gene TNFRSF25, DPP-IV, a cell surface protein that suppresses development of melanoma, MCM2, MCM3, MCM4, and MCM5, which code for DNA replication licensing factor, CDK1, which acts as a serine/threonine kinase and is a key player in cell cycle regulation, CDC20, which regulates cell division, Xiap, or x-linked inhibitor of apoptotis protein, Livin, another anti-apoptotic gene, Hsp60 and Hsp70, heat shock proteins responsible for responsible for the transportation and refolding of proteins from the cytoplasm into the mitochondrial matrix, Trail R2/DR5, an anti-inflammatory cytokine, and rck/p54, a DEAD box protein (SEQ ID NO: 9) that has been shown to be overexpressed in colorectal cancers.
[0000] RNA Interference and siNA
[0063] RNA interference refers to the process of sequence-specific post-transcriptional gene silencing in animals mediated by short interfering RNAs (siRNAs) (Zamore et al., 2000, Cell, 101, 25-33; Fire et al., 1998, Nature, 391, 806; Hamilton et al., 1999, Science, 286, 950-951; Lin et al., 1999, Nature, 402, 128-129; Sharp, 1999, Genes & Dev., 13:139-141; and Strauss, 1999, Science, 286, 886). Post-transcriptional gene silencing is believed to be an evolutionarily-conserved cellular mechanism for preventing expression of foreign genes that may be introduced into the host cell (Fire et al., 1999, Trends Genet., 15, 358). Post-transcriptional gene silencing may be an evolutionary response to the production of double-stranded RNAs (dsRNAs) resulting from viral infection or from the random integration of transposable elements (transposons) into a host genome. The presence of dsRNA in cells triggers the RNAi response that appears to be different from other known mechanisms involving double stranded RNA-specific ribonucleases, such as the interferon response that results from dsRNA-mediated activation of protein kinase PKR and 2′,5′-oligoadenylate synthetase resulting in non-specific cleavage of mRNA by ribonuclease L (see for example U.S. Pat. Nos. 6,107,094; 5,898,031; Clemens et al., 1997, J. Interferon & Cytokine Res., 17, 503-524; Adah et al., 2001, Curr. Med. Chem., 8, 1189).
[0064] The presence of long dsRNAs in cells stimulates the activity of dicer, a ribonuclease III enzyme (Bass, 2000, Cell, 101, 235; Zamore et al., 2000, Cell, 101, 25-33; Hammond et al., 2000, Nature, 404, 293). Dicer processes long dsRNA into double-stranded short interfering RNAs (siRNAs) which are typically about 21 to about 23 nucleotides in length and include about 19 base pair duplexes (Zamore et al., 2000, Cell, 101, 25-33; Bass, 2000, Cell, 101, 235; Elbashir et al., 2001, Genes Dev., 15, 188).
[0065] Single-stranded RNA, including the sense strand of siRNA, trigger an RNAi response mediated by an endonuclease complex known as an RNA-induced silencing complex (RISC). RISC mediates cleavage of this single-stranded RNA in the middle of the siRNA duplex region (i.e., the region complementary to the antisense strand of the siRNA duplex) (Elbashir et al., 2001, Genes Dev., 15, 188).
[0066] In certain embodiments, the siNAs may be a substrate for the cytoplasmic Dicer enzyme (i.e., a “Dicer substrate”) which is characterized as a double stranded nucleic acid capable of being processed in vivo by Dicer to produce an active nucleic acid molecules. The activity of Dicer and requirements for Dicer substrates are described, for example, U.S. 2005/0244858. Briefly, it has been found that dsRNA, having about 25 to about 30 nucleotides, effective result in a down-regulation of gene expression. Without wishing to be bound by any theory, it is believed that Dicer cleaves the longer double stranded nucleic acid into shorter segments and facilitates the incorporation of the single-stranded cleavage products into the RNA-induced silencing complex (RISC complex). The active RISC complex, containing a single-stranded nucleic acid cleaves the cytoplasmic RNA having complementary sequences.
[0067] It is believed that Dicer substrates must conform to certain general requirements in order to be processed by Dicer. The Dicer substrates must of a sufficient length (about 25 to about 30 nucleotides) to produce an active nucleic acid molecule and may further include one or more of the following properties: (i) the dsRNA is asymmetric, e.g., has a 3′ overhang on the first strand (antisense strand) and (ii) the dsRNA has a modified 3′ end on the antisense strand (sense strand) to direct orientation of Dicer binding and processing of the dsRNA to an active siRNA. The Dicer substrates may be symmetric or asymmetric. For example, Dicer substrates may have a sense strand includes 22-28 nucleotides and the antisense strand may include 24-30 nucleotides, resulting in duplex regions of about 25 to about 30 nucleotides, optionally having 3′-overhangs of 1-3 nucleotides.
[0068] Dicer substrates may have any modifications to the nucleotide base, sugar or phosphate backbone as known in the art and/or as described herein for other nucleic acid molecules (such as siNA molecules).
[0069] The RNAi pathway may be induced in mammalian and other cells by the introduction of synthetic siRNAs that are 21 nucleotides in length (Elbashir et al., 2001, Nature, 411, 494 and Tuschl et al., WO 01/75164; incorporated by reference in their entirety). Other examples of the requirements necessary to induce the down-regulation of gene expression by RNAi are described in Zamore et al., 2000, Cell, 101, 25-33; Bass, 2001, Nature, 411, 428-429; Kreutzer et al., WO 00/44895; Zernicka-Goetz et al., WO 01/36646; Fire, WO 99/32619; Plaetinck et al., WO 00/01846; Mello and Fire, WO 01/29058; Deschamps-Depaillette, WO 99/07409; and Li et al., WO 00/44914; Allshire, 2002, Science, 297, 1818-1819; Volpe et al., 2002, Science, 297, 1833-1837; Jenuwein, 2002, Science, 297, 2215-2218; and Hall et al., 2002, Science, 297, 2232-2237; Hutvagner and Zamore, 2002, Science, 297, 2056-60; McManus et al., 2002, RNA, 8, 842-850; Reinhart et al., 2002, Gene & Dev., 16, 1616-1626; and Reinhart & Bartel, 2002, Science, 297, 1831; each of which is hereby incorporated by reference in its entirety.
[0070] Briefly, an siNA nucleic acid molecule can be assembled from two separate polynucleotide strands (a sense strand and an antisense strand) that are at least partially complementary and capable of forming stable duplexes. The length of the duplex region may vary from about 15 to about 49 nucleotides (e.g., about 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, or 49 nucleotides). Typically, the antisense strand includes nucleotide sequence that is complementary to nucleotide sequence in a target nucleic acid molecule. The sense strand includes nucleotide sequence corresponding to the target nucleic acid sequence which is therefore at least substantially complementary to the antisense stand. Optionally, an siNA is “RISC length” and/or may be a substrate for the Dicer enzyme. Optionally, an siNA nucleic acid molecule may be assembled from a single polynucleotide, where the sense and antisense regions of the nucleic acid molecules are linked such that the antisense region and sense region fold to form a duplex region (i.e., forming a hairpin structure).
5′ Ends, 3′ Ends and Overhangs
[0071] siNAs may be blunt-ended on both sides, have overhangs on both sides or a combination of blunt and overhang ends. Overhangs may occur on either the 5′- or 3′-end of the sense or antisense strand. Overhangs typically consist of 1-8 nucleotides (e.g., 1, 2, 3, 4, 5, 6, 7, or 8 nucleotides each) and are not necessarily the same length on the 5′- and 3′-end of the siNA duplex. The nucleotide(s) forming the overhang need not be of the same character as those of the duplex region and may include deoxyribonucleotide(s), ribonucleotide(s), natural and non-natural nucleobases or any nucleotide modified in the sugar, base or phosphate group such as disclosed herein.
[0072] The 5′- and/or 3′-end of one or both strands of the nucleic acid may include a free hydroxyl group or may contain a chemical modification to improve stability. Examples of end modifications (e.g., terminal caps) include, but are not limited to, abasic, deoxy abasic, inverted (deoxy) abasic, glyceryl, dinucleotide, acyclic nucleotide, amino, fluoro, chloro, bromo, CN, CF, methoxy, imidazole, carboxylate, thioate, C1 to C10 lower alkyl, substituted lower alkyl, alkaryl or aralkyl, OCF3, OCN, O-, S-, or N-alkyl; O-, S-, or N-alkenyl; SOCH3; SO2CH3; ONO2; NO2, N3; heterocycloalkyl; heterocycloalkaryl; aminoalkylamino; polyalkylamino or substituted silyl, as, among others, described in European patents EP 586,520 and EP 618,925.
Chemical Modifications
[0073] siNA molecules optionally may contain one or more chemical modifications to one or more nucleotides. There is no requirement that chemical modifications are of the same type or in the same location on each of the siNA strands. Thus, each of the sense and antisense strands of an siNA may contain a mixture of modified and unmodified nucleotides. Modifications may be made for any suitable purpose including, for example, to increase RNAi activity, increase the in vivo stability of the molecules (e.g., when present in the blood), and/or to increase bioavailability.
[0074] Suitable modifications include, for example, internucleotide or internucleoside linkages, dideoxyribonucleotides, 2′-sugar modification including amino, fluoro, methoxy, alkoxy and alkyl modifications; 2′-deoxyribonucleotides, 2′-O-methyl ribonucleotides, 2′-deoxy-2′-fluoro ribonucleotides, “universal base” nucleotides, “acyclic” nucleotides, 5-C-methyl nucleotides, biotin group, and terminal glyceryl and/or inverted deoxy abasic residue incorporation, sterically hindered molecules, such as fluorescent molecules and the like. Other nucleotides modifiers could include 3′-deoxyadenosine (cordycepin), 3′-azido-3′-deoxythymidine (AZT), 2′,3′-dideoxyinosine (ddI), 2′,3′-dideoxy-3′-thiacytidine (3TC), 2′,3′-didehydro-2′,3′-dideoxythymidi-ne (d4T) and the monophosphate nucleotides of 3′-azido-3′-deoxythymidine (AZT), 2′,3′-dideoxy-3′-thiacytidine (3TC) and 2′,3′-didehydro-2′,3′-dide-oxythymidine (d4T).
[0075] Other suitable modifications include, for example, locked nucleic acid (LNA) nucleotides (e.g., 2′-O, 4′-C-methylene-(D-ribofuranosyl) nucleotides); 2′-methoxyethoxy (MOE) nucleotides; 2′-methyl-thio-ethyl, 2′-deoxy-2′-fluoro nucleotides, 2′-deoxy-2′-chloro nucleotides, 2′-azido nucleotides, and 2′-O-methyl nucleotides (WO 00/47599, WO 99/14226, WO 98/39352, and WO 2004/083430).
[0076] Chemical modifications also include terminal modifications on the 5′ and/or 3′ part of the oligonucleotides and are also known as capping moieties. Such terminal modifications are selected from a nucleotide, a modified nucleotide, a lipid, a peptide, and a sugar.
[0077] Chemical modifications also include L-nucleotides. Optionally, the L-nucleotides may further include at least one sugar or base modification and/or a backbone modification as described herein.
Delivery of Nucleic Acid-Containing Pharmaceutical Formulations
[0078] Nucleic acid molecules disclosed herein (including siNAs and Dicer substrates) may be administered with a carrier or diluent or with a delivery vehicle which facilitate entry to the cell. Suitable delivery vehicles include, for example, viral vectors, viral particles, liposome formulations, and lipofectin.
[0079] Methods for the delivery of nucleic acid molecules are described in Akhtar et al., Trends Cell Bio., 2: 139 (1992); Delivery Strategies for Antisense Oligonucleotide Therapeutics, ed. Akhtar, (1995), Maurer et al., Mol. Membr. Biol., 16: 129-140 (1999); Hofland and Huang, Handb. Exp. Pharmacol., 137: 165-192 (1999); and Lee et al., ACS Symp. Ser., 752: 184-192 (2000); U.S. Pat. Nos. 6,395,713; 6,235,310; 5,225,182; 5,169,383; 5,167,616; 4,959,217; 4,925,678; 4,487,603; and 4,486,194; WO 94/02595; WO 00/03683; WO 02/08754; and U.S. 2003/077829.
[0080] Nucleic acid molecules can be administered to cells by a variety of methods known to those of skill in the art, including, but not restricted to, encapsulation in liposomes, by iontophoresis, or by incorporation into other vehicles, such as biodegradable polymers, hydrogels, cyclodextrins (see e.g., Gonzalez et al., Bioconjugate Chem., 10: 1068-1074 (1999); WO 03/47518; and WO 03/46185), poly(lactic-co-glycolic)acid (PLGA) and PLCA microspheres (see for example U.S. Pat. No. 6,447,796 and U.S. 2002/130430), biodegradable nanocapsules, and bioadhesive microspheres, or by proteinaceous vectors (WO 00/53722). Alternatively, the nucleic acid/vehicle combination is locally delivered by direct injection or by use of an infusion pump. Direct injection of the nucleic acid molecules of the invention, whether subcutaneous, intramuscular, or intradermal, can take place using standard needle and syringe methodologies, or by needle-free technologies such as those described in Conry et al., Clin. Cancer Res., 5: 2330-2337 (1999) and WO 99/31262. The molecules of the instant invention can be used as pharmaceutical agents.
[0081] Nucleic acid molecules may be complexed with cationic lipids, packaged within liposomes, or otherwise delivered to target cells or tissues. The nucleic acid or nucleic acid complexes can be locally administered to relevant tissues ex vivo, or in vivo through direct dermal application, transdermal application, or injection, with or without their incorporation in biopolymers. Delivery systems include surface-modified liposomes containing poly (ethylene glycol) lipids (PEG-modified, or long-circulating liposomes or stealth liposomes).
[0082] Nucleic acid molecules may be formulated or complexed with polyethylenimine (e.g., linear or branched PEI) and/or polyethylenimine derivatives, including for example polyethyleneimine-polyethyleneglycol-N-acetylgalactosamine (PEI-PEG-GAL) or polyethyleneimine-polyethyleneglycol-tri-N-acetylgalactosamine (PEI-PEG-triGAL) derivatives, grafted PEIs such as galactose PEI, cholesterol PEI, antibody derivatized PEI, and polyethylene glycol PEI (PEG-PEI) derivatives thereof (see, for example Ogris et al., 2001, AAPA PharmSci, 3, 1-11; Furgeson et al., 2003, Bioconjugate Chem., 14, 840-847; Kunath et al., 2002, Pharmaceutical Research, 19, 810-817; Choi et al., 2001, Bull. Korean Chem. Soc., 22, 46-52; Bettinger et al., 1999, Bioconjugate Chem., 10, 558-561; Peterson et al., 2002, Bioconjugate Chem., 13, 845-854; Erbacher et al., 1999, Journal of Gene Medicine Preprint, 1, 1-18; Godbey et al., 1999., PNAS USA, 96, 5177-5181; Godbey et al., 1999, Journal of Controlled Release, 60, 149-160; Diebold et al., 1999, Journal of Biological Chemistry, 274, 19087-19094; Thomas and Klibanov, 2002, PNAS USA, 99, 14640-14645; U.S. Pat. No. 6,586,524 and U.S. 2003/0077829).
[0083] Delivery systems may include, for example, aqueous and nonaqueous gels, creams, multiple emulsions, microemulsions, liposomes, ointments, aqueous and nonaqueous solutions, lotions, aerosols, hydrocarbon bases and powders, and can contain excipients such as solubilizers, permeation enhancers (e.g., fatty acids, fatty acid esters, fatty alcohols and amino acids), and hydrophilic polymers (e.g., polycarbophil and polyvinylpyrolidone). In one embodiment, the pharmaceutically acceptable carrier is a liposome or a transdermal enhancer. Examples of liposomes which can be used in this invention include the following: (1) CellFectin, 1:1.5 (M/M) liposome formulation of the cationic lipid N,NI,NII,NIII-tetramethyl-N,NI,NII,NIII-tetrapalmit-y-spermine and dioleoyl phosphatidylethanolamine (DOPE) (GIBCO BRL); (2) Cytofectin GSV, 2:1 (M/M) liposome formulation of a cationic lipid and DOPE (Glen Research); (3) DOTAP (N-[1-(2,3-dioleoyloxy)-N,N,N-tri-methyl-ammoniummethylsulfate) (Boehringer Manheim); and (4) Lipofectamine, 3:1 (M/M) liposome formulation of the polycationic lipid DOSPA, the neutral lipid DOPE (GIBCO BRL) and Di-Alkylated Amino Acid (DiLA2).
[0084] Therapeutic nucleic acid molecules may be expressed from transcription units inserted into DNA or RNA vectors. Recombinant vectors can be DNA plasmids or viral vectors. Nucleic acid molecule expressing viral vectors can be constructed based on, but not limited to, adeno-associated virus, retrovirus, adenovirus, or alphavirus. The recombinant vectors are capable of expressing the nucleic acid molecules either permanently or transiently in target cells. Delivery of nucleic acid molecule expressing vectors can be systemic, such as by intravenous, subcutaneous, or intramuscular administration.
[0085] Expression vectors may include a nucleic acid sequence encoding at least one nucleic acid molecule disclosed herein, in a manner which allows expression of the nucleic acid molecule. For example, the vector may contain sequence(s) encoding both strands of a nucleic acid molecule that include a duplex. The vector can also contain sequence(s) encoding a single nucleic acid molecule that is self-complementary and thus forms a nucleic acid molecule. Non-limiting examples of such expression vectors are described in Paul et al., 2002, Nature Biotechnology, 19, 505; Miyagishi and Taira, 2002, Nature Biotechnology, 19, 497; Lee et al., 2002, Nature Biotechnology, 19, 500; and Novina et al., 2002, Nature Medicine. An expression vector may encode one or both strands of a nucleic acid duplex, or a single self-complementary strand that self hybridizes into a nucleic acid duplex. The nucleic acid sequences encoding nucleic acid molecules can be operably linked to a transcriptional regulatory element that results expression of the nucleic acid molecule in the target cell. Transcriptional regulatory elements may include one or more transcription initiation regions (e.g., eukaryotic pol I, II or III initiation region) and/or transcription termination regions (e.g., eukaryotic pol I, II or III termination region). The vector can optionally include an open reading frame (ORF) for a protein operably linked on the 5′ side or the 3′-side of the sequence encoding the nucleic acid molecule; and/or an intron (intervening sequences).
[0086] The nucleic acid molecules or the vector construct can be introduced into the cell using suitable formulations. One preferable formulation is with a lipid formulation such as in Lipofectamine™ 2000 (Invitrogen, CA, USA), vitamin A coupled liposomes (Sato et al. Nat Biotechnol 2008; 26:431-442, PCT Patent Publication No. WO 2006/068232). Lipid formulations can also be administered to animals such as by intravenous, intramuscular, or intraperitoneal injection, or orally or by inhalation or other methods as are known in the art. When the formulation is suitable for administration into animals such as mammals and more specifically humans, the formulation is also pharmaceutically acceptable. Pharmaceutically acceptable formulations for administering oligonucleotides are known and can be used. In some instances, it may be preferable to formulate dsRNA in a buffer or saline solution and directly inject the formulated dsRNA into cells, as in studies with oocytes. The direct injection of dsRNA duplexes may also be done. Suitable methods of introducing dsRNA are provided, for example, in U.S. 2004/0203145 and U.S. 20070265220.
[0087] Polymeric nanocapsules or microcapsules facilitate transport and release of the encapsulated or bound dsRNA into the cell. They include polymeric and monomeric materials, especially including polybutylcyanoacrylate. The polymeric materials which are formed from monomeric and/or oligomeric precursors in the polymerization/nanoparticle generation step, are per se known from the prior art, as are the molecular weights and molecular weight distribution of the polymeric material which a person skilled in the field of manufacturing nanoparticles may suitably select in accordance with the usual skill.
[0088] Nucleic acid moles may be formulated as a microemulsion. A microemulsion is a system of water, oil and amphiphile which is a single optically isotropic and thermodynamically stable liquid solution. Typically microemulsions are prepared by first dispersing an oil in an aqueous surfactant solution and then adding a sufficient amount of a 4th component, generally an intermediate chain-length alcohol to form a transparent system. Surfactants that may be used in the preparation of microemulsions include, but are not limited to, ionic surfactants, non-ionic surfactants, Brij 96, polyoxyethylene oleyl ethers, polyglycerol fatty acid esters, tetraglycerol monolaurate (ML310), tetraglycerol monooleate (MO310), hexaglycerol monooleate (PO310), hexaglycerol pentaoleate (PO500), decaglycerol monocaprate (MCA750), decaglycerol monooleate (MO750), decaglycerol sequioleate (SO750), decaglycerol decaoleate (DAO750), alone or in combination with cosurfactants. The cosurfactant, usually a short-chain alcohol such as ethanol, 1-propanol, and 1-butanol, serves to increase the interfacial fluidity by penetrating into the surfactant film and consequently creating a disordered film because of the void space generated among surfactant molecules.
EXAMPLES
[0089] The present methods, thus generally described, will be understood more readily by reference to the following examples, which are provided by way of illustration and are not intended to be limiting of the present methods and kits.
Example 1
Differentially Regulated lncRNAs in Melanoma Cells
[0090] One microgram of total RNA was labeled and hybridized to NCode human microarrays (Life Technologies™, Carlsbad, Calif., USA) and labeled according to the manufacturer's protocols (Life Technologies Corp., Carlsbad, Calif.). An Agilent 2 μm high resolution C scanner (Cat # G2365CA) was used to scan the slides and the data was normalized and analyzed using GeneSpring software (Agilent Technologies). The NCode human array contains over 10,000 putative lncRNAs (>200 nt) including most of the known lncRNAs in human. Lack of coding potential was estimated by a previously described algorithm [11] that scores various characteristics of protein-coding genes, including open reading frame length, synonymous/non-synonymous base substitution rates and similarity to known protein. These arrays are the first generation of tools designed to investigate the dynamic expression of a large subset of lncRNAs in human to identify candidate genes for more detailed functional analysis. In addition to the lncRNA content, probes targeting mRNA content from RefSeq are also included, allowing discovery of coordinated expression with associated protein-coding genes.
[0091] To identify lncRNAs involved in melanoma, total RNA from a stage III melanoma cell line (WM1552C), melanocytes, and keratinocytes, was analyzed using a non-coding RNA microarray (Ncode human array from Life Technologies). NCode human microarrays contain probes to target 12,784 lncRNAs and 25,409 mRNAs. In total, we identified 77 lncRNAs that were significantly differentially expressed (P<0.015; fold-change) in WM1552C relative to melanocytes. In addition to cell line profiling, 29 independent melanoma patient samples (graded as primary in situ, regional metastatic, distant metastatic and nodal metastatic), and six normal skin samples were also analyzed using the same microarrays. The differential lncRNA expression is presented as a hierarchical cluster ( FIG. 6 ). Hierarchical clustering was done using the GeneSpring™ software (Agilent Technologies) and R package. The primary criteria in candidate selection for functional studies was whether the differentially expressed lncRNAs in melanoma cell lines were also differentially expressed in patient samples. Four candidate non-coding RNAs were screened initially ( FIGS. 1A, 1B and 7A-7D ). lncRNA SPRY4-IT1 (Genbank Accession ID AK024556; SEQ ID NO: 1) is one such candidate that differentially expressed in both melanoma cell lines and patients samples relative to melanocytes.
[0092] SPRY4-IT1 was selected for functional studies based on the criteria above. SPRY4-IT1 expression was further confirmed by deep-sequencing. SPRY4-IT1 expression was more than 12-fold higher in melanoma cells (WM1552C) relative to melanocytes. A comparison of SPRY4-IT1 in kidney, blood, and breast cell lines revealed expression to be equal to that of melanocytes or less ( FIG. 8 ). We then measured the expression levels of SPRY4-IT1 ( FIG. 1C ) as well as the SPRY4 ORF ( FIGS. 9A-9D ) in seven additional non-pigmented melanoma cell lines (WM793B, A375, SKMEL-2, RPMI 7951, HT-144, LOX-IMV1, and G361) by qRT-PCR and the results showed that the expression of both was elevated in most of the melanoma cell lines relative to control melanocytes.
Example 2
Structural Prediction of SPRY4-IT1
[0093] The most recent versions of RNAfold and RNAstructure were employed for generating RNA secondary structures. The partition function algorithm was chosen for two reasons: (i) it produces a structure almost identical to the minimum free energy algorithm with RNAfold with few proximal sub-optimal structures, and (ii) it is required for subsequent prediction of pseudoknots with ProbKnot (included in RNAstructure).
[0094] The evolutionary conservation of secondary structures was conducted with the consensus-based programs RNAz and SISSIz on the Enredo-Pecan-Ortheus 31-way eutherian mammal genome alignment from ENSEMBL. Orthologous sequences to SPRY4-IT1 were selected and realigned with MAFFT using the mafft-ginsi algorithm. Sliding window ranges of 100 nt window with 25 nt slide, 150 nt window with 50 nt slide, and 300 nt window with 100 nt slide were tested with both RNAz and SISSIz, using parameters “−d” and “−d−t−n 200−p 0.02”, respectively.
[0095] SPRY4-IT1 is a 687 nt unspliced, polyadenylated transcript originally identified in adipose tissue and is transcribed from the intronic region of the SPRY4 gene ( FIG. 1A ). This region is not conserved beyond the primate genomes and there is no EST expression detected in mouse. To determine whether the SPRY4-IT1 RNA contained any particular secondary structural features, the SPRY4-IT1 genomic sequence was submitted to secondary structure and pseudoknot prediction using two different programs that implement an RNA partition function algorithm. The results appear in FIG. 1D , wherein blue lines indicate positions of pseudo knots, and red base-pairing indicates regions of consensus structure between the two algorithms. Several helical regions are common to both algorithms, including a large stem-loop from positions 220 to 321 ( FIG. 1D ). The latter encompasses one of two non-repeat associated “pyknons”, putative regulatory motifs that are non-randomly distributed throughout the genome. In addition, three putative pseudoknots (i.e. nested helices) are predicted by ProbKnot, which boasts high sensitivity and positive prediction value. No compatible structures appear to be significantly conserved throughout a multiple alignment of orthologous sequences from 31 eutherian mammals. The likelihood that it could fold into long stable hairpin structures ( FIG. 1B ), suggests that SPRY4-IT1 may function intrinsically as a RNA molecule.
Example 3
Expression Profiling of SPRY4 and SPRY4-IT1 in Human Tissue
[0096] SPRY4 is an inhibitor of the receptor-transduced mitogen-activated protein kinase (MAPK) signaling pathway. It functions upstream of RAS activation and impairs the formation of active GTP-RAS. SPRY4 is down-regulated in non-small cell lung cancer and inhibits cell growth, migration, and invasion in transfected cell lines, suggesting it may function as a tumor suppressor. SPRY4 occurs in two alternately spliced isoforms, termed SPRY4.1 and SPRY4.2 ( FIG. 1A ), the latter of which retains an additional exon that results in translation initiating from an alternate start codon. To better understand where SPRY4 functions and the relative expression of the two isoforms, qRT-PCR was used to measure the expression of SPRY4.1 and SPRY4.2 across 20 human tissues ( FIG. 11A-11C ). The results showed that both isoforms are expressed in all tissues examined, with the highest expression found in the lung and placenta and lowest in the thymus and oesophagus. SPRY4.1 was found to be the more abundant isoform, occurring in diverse ratios (relative to SPRY4.2) across different tissues, ranging from 2.7:1 in kidney to 28:1 in thyroid. Despite the differences in abundance, the expression profiles of SPRY4.1 and SPRY4.2 were positively correlated (R=0.75; Pearson correlation).
[0097] Given the intronic position of SPRY4-IT1 within SPRY4, it was next determined whether the expression of SPRY4-IT1 and SPRY4 were linked. Therefore, in order to ascertain any linkage the relative expression of SPRY4-IT1 across the same panel of 20 human tissues was examined ( FIG. 2A ). Interestingly, in several tissues, SPRY4-IT1 was more highly expressed than SPRY4.1, occurring at ratios as high as 4.5:1 in kidney ( FIG. 2B ). Furthermore, the range in expression for SPRY4-IT1 across the 20 different tissues was much greater than that of SPRY4; SPRY4-IT1 varied by as much as 111-fold (placenta vs oesophagus) compared to SPRY4.1, which varied by a maximum of ˜10-fold (thyroid vs kidney). Despite the variation in abundance and range, the expression profile of SPRY4-IT1 was correlated with both SPRY4.1 (R=0.62; Pearson correlation) and SPRY4.2 (R=0.84; Pearson correlation). The similar expression profiles between SPRY4-IT1 and SPRY4 suggests that SPRY4-IT1 and SPRY4 may share the same transcriptional regulatory factors or indeed may be processed directly from the intron of SPRY4. In the latter scenario, the higher abundance of SPRY4-IT1 could be explained by higher stability of the lncRNA relative to the mRNA.
[0098] Total RNA was isolated using Trizol (Life Technologies) with subsequent quantification by using an Agilent 2100 Bioanalyzer (Agilent Technologies, Santa Clara, Calif., USA). 1 μg of total RNA was reverse transcribed using the High Capacity cDNA kit (Applied Biosystems Inc., Foster City, Calif., USA), and qRT-PCR was carried out using TaqMan Assays in the 7500 Real-Time PCR System (Applied Biosystems) according to the manufacturer's protocols. SDS1.2.3 software (Applied Biosystems) was used for comparative Ct analysis with GAPDH serving as the endogenous control.
[0099] Next generation sequencing experiments show that SPRY1 and SPRY3 have little or no expression in either melanoma or melanocytes, but both SPRY2 and SPRY4 are highly expressed in melanoma cells compared to melanocytes ( FIG. 10 ).
[0100] For the human tissue expression analysis, total RNA from 20 different tissues was purchased from Ambion. 1 ug was oligo-dT reverse transcribed using Superscript III (Life Technologies) and qRT-PCR was carried out using the TaqMan Noncoding RNA Assays (SPRY4-IT1) and TaqMan Gene Expression Assays (SPRY4.1 and SPRY4.2) in the 7900 Real-Time PCR System (Applied Biosystems) according to the manufacturer's protocols. SDS2.3 software (Applied Biosystems) was used for comparative Ct analysis with RPLO serving as the endogenous control.
Example 4
SPRY4-IT1 and SPRY4 Expression in Patient Tissue Samples
[0101] The expression of SPRY4-IT1 and SPRY4 in 25 melanoma patient samples was then examined using quantitative RT-PCR ( FIGS. 3A-D ). The expression of both SPRY4-IT1 and SPRY4.2 varied considerably between patient samples but their relative expression levels were highly correlated (R=0.95; FIGS. 12A-12D ). These results validated the microarray expression data, showing that SPRY4-IT1 was up-regulated in melanoma patient samples compared to the melanocyte control ( FIG. 3A-3D ).
[0102] Additionally, relative expression of SPRY4-IT1 to SPRY4.2 in primary, nodal metastasis, regional metastasis, and distant metastasis in melanoma patient samples. The results are shown in FIG. 12A-12D .
[0103] Finally, the expression of SPRY4-IT1 in tumor cells of 18 organs was measured and compared to normal tissue expression. The results, which are shown in FIGS. 22A and 22B , show that the highest level of expression was found in the adrenal gland, the stomach, the uterus, and the testis. A number of samples from each of the organs with highest expression levels of SPRY4-IT1 were then subjected to RT-PCR to calculate the expression level of SPRY4-IT1 in each sample. The results are given in FIG. 22C - FIG. 23A-23F , and confirm the presence of ectopic SPRY4-IT1 in tumor cells other than melanoma.
Example 5
RNAi to Knock-Down SPRY4-IT1 in Melanoma Cells
[0104] Five different Stealth RNAi™ siRNAs that targeted SPRY4-IT1 RNA and a Scramble Stealth RNAi™ siRNA control were used to knock down SPRY4-IT1 RNA in melanoma cells (Life Technologies). The Stealth RNAi™ siRNA molecules are 25 base-pair double-stranded RNA oligonucleotides with proprietary chemical modifications. The BLOCK-iT RNAi designer was used to find gene-specific 25 nucleotide Stealth RNAi™ siRNA molecules. It uses gene-specific targets for RNAi analysis and reports up to 10 top scoring Stealth RNAi™ siRNA targets. The freeze-dried siRNAs were dissolved in RNase free-water and stored as aliquots at −20° C. The siRNA with the sequence GCTTTCTGATTCCAAGGCCTATTAA (SEQ ID NO: 2) yielded the highest degree of SPRY4-IT1-knockdown.
Cell Culture Conditions and Transfection
[0105] Transfection was done with Lipofectamine™ RNAiMax (Life Technologies) in 6 well plates. 6, 12 and 18 nM RNAi duplexes were diluted in 500 μL serum free medium, mixed gently and 5 μL of Lipofectamine™ RNAiMAX was added to each well containing the diluted RNAi molecules. This mixture was incubated for 20 minutes at room temperature before the transfection. 250,000 cells were diluted in complete Tu growth medium (without antibiotics) and plated in each well. RNAi duplex—Lipofectamine™ RNAiMAX complexes were added to each well and mixed gently by rocking the plate. Cells were incubated for 48 hours at 37° C. in a CO 2 incubator and gene knockdown was assessed by qRT-PCR.
Northern Blot Analysis
[0106] Total RNA concentrated from each sample (20 μg) was separated in 15% TBE-urea polyacrylamide gels by electrophoresis. The RNA was electroblotted onto nylon membranes, cross-linked by ultraviolet light, prehybridized in Ultrahyb-Oligo (Ambion) for 30 min at 42° C., and hybridized at 100 nM with a 5′-biotinylated anti-miRNA DNA oligonucleotide (TCCACTGGGCATATTCTAAAA; SEQ ID NO: 3) at 42° C. overnight. The blots were then washed, and the signal was detected by chemiluminiscence (Brightstar Detection kit, Ambion). Anti-U6 probes (10 pM) were used as a reference control.
RNA-FISH Analysis
[0107] Locked nucleic acid (LNA)-modified probes for human lncRNA SPRY4-IT1 (5′-FAM-TCCACTGGGCATATTCTAAAA-3′-FAM; SEQ ID NO: 3) and a negative/Scramble control (5′-TYE665-GTGTAACACGTCTATACGCCCA-3′-TYE665 (SEQ ID NO: 4), miRCURY-LNA detection probe, Exiqon) were used for RNA in situ hybridization. In situ hybridization was performed using the RiboMap in situ hybridization kit (Ventana Medical Systems Inc) on a Ventana machine. The cell suspension diluted to 10,000 cells per 100 μL was pipetted into clonal rings on the autoclaved glass slides. The following day, the clonal rings were removed; slides were washed in PBS and fixed in 4% paraformaldehyde and 5% acetic acid. After acid treatment using hydrochloride-based RiboClear reagent (Ventana Medical Systems) for 10 min at 37° C., the slides were treated with the ready-to-use protease 3 reagent. The cells were hybridized with the antisense LNA riboprobe (40 nM) using RiboHybe hybridization buffer (Ventana Medical Systems) for 2 h at 58° C. after an initial denaturing prehybridization step for 4 min at 80° C. Next, the slides were subjected to a low-stringency wash with 0.1×SSC (Ventana Medical Systems) for 4 min at 60° C., and then two further washing steps with 1×SSC for 4 min at 60° C. These slides were fixed in RiboFix and counterstained with 4′-6′diamidino-2-phenylindole (DAPI), in an antifade reagent (Ventana). The images were acquired using a Nikon AIR VAAS laser point- and resonant-scanning confocal microscope equipped with a single photon Ar-ion laser at 60× with 4× zoom.
[0108] To probe the functional role of SPRY4-IT1, Stealth RNAi was used to down-regulate SPRY4-IT1 expression in melanoma cells. Five different stealth RNAi molecules were tested for their knockdown efficiency, the most efficient of which (stealth RNAi 594) was selected for subsequent biological studies. To determine the optimal concentration for knockdown, several different concentrations of stealth siRNA were examined in the melanoma cell lines A375 and WM1552C ( FIGS. 4A and 4B ). When these cells were transfected with 6 nM of stealth siRNA, it showed a 45% SPRY4-IT1 silencing in A375 cells, but no significant changes were observed in WM1552C cells. However, 18 nM of stealth RNAi yielded at least 60% knock-down in both cell lines (WM1552C and A375). These results were validated by northern blot analysis ( FIG. 4C ). Though a high level of SPRY4-IT1 knock-down occurred with 30 nM siRNA, significant cell death also occurred. Therefore, subsequent cell biology studies were performed with a maximum of 18 nM stealth siRNA. Stealth RNAi-transfected A375 cells were also screened for their expression of SPRY4, revealing no changes in expression (indicating that the down-regulation of the lncRNA SPRY4-IT1 did not effect the expression of the SPRY4 ORF) ( FIG. 10 ).
[0109] Given the correlated expression of SPRY4-IT1 and SPRY4, the effect of SPRY4-IT1 knockdown on SPRY4 was investigated in A375 cells using qRT-PCR. It was found that the level of SPRY4 expression was not significantly altered following SPRY4-IT1 knockdown relative to the scrambled siRNA control ( FIG. 13 ). This confirms that the RNAi knockdown strategy does not appreciably alter the expression levels of the host SPRY4 transcript. The phenotypic effects observed following knockdown of SPRY4-IT1 result directed from SPRY4-IT1 and not from the regulation of SPRY4 by SPRY4-IT1.
[0110] The expression of lncRNA SPRY4-IT1 in A375 cell lines and melanocytes was then examined by in situ hybridization using a locked nucleic acid (LNA) FAM-labeled probe (see Methods). RNA FISH showed that SPRY4-IT1 is localized as a punctuate pattern in the nucleus, but the majority of the signal was observed in the cell cytoplasm ( FIG. 4D ). Consistent with previous qRT-PCR results ( FIG. 1C ), RNA FISH also revealed that SPRY4-IT1 was highly expressed in A375 melanoma cell lines compared to melanocytes. The dose-dependent reduction of RNA-FISH signal in A375 cells transfected with different concentrations of SPRY4-IT1-targeted siRNAs show that the probe was specifically detecting the SPRY4-IT1 transcript.
Example 6
SPRY4-IT1 Inhibition Effects Metabolic Viability and Cell Death
Metabolic Viability by MTT Assay
[0111] To investigate the possible role of SPRY4-IT1 on the growth of melanoma cells, the metabolic viability was assessed using a colorimetric assay, which involves the conversion of MTT in active mitochondria of living cells to formazan. The amount of formazan correlates with the number of viable cells. MTT (3-(4,5-dimethyl-2-yl)-2,5-diphenyl-2II-tetrazolium bromide) was purchased from Roche. Cells were plated in 96 well plates (5000 cells/100 μL/well). After 48 h of transfection, 20 μL MTT solution was added and the cells were incubated at 37° C. in the dark for 4 h. The generated formazan OD was measured at 490 nm to determine the cell viability on the Flex station (Molecular Devices).
[0112] A375 melanoma cells knocked-down with Stealth siRNA showed a 50% decrease in metabolic viability 48 hours after transfection, whereas WM1552C cells showed a 30% decrease in viability ( FIGS. 5A & 5B ). The MTT assay demonstrates that the down-regulation of SPRY4-IT1 expression decreases cell growth in melanoma cells.
Phosphatidylserine Externalization
[0113] Next, the effects of SPRY4-IT1 knock-down on apoptosis were investigated. Apoptosis was detected by labeling phosphotidylserine using FITC-conjugated Annexin V in unfixed cells. Cell death was studied by flow cytometry using Annexin V. Annexin V binds to the negatively charged phospholipids located on the inner surface of the plasma membrane. Annexin V conjugated to fluorescein together with propidium iodide is used to detect non-apoptotic live cells (Annexin V negative, PI negative), early apoptotic cells (Annexin V positive, PI negative) and late apoptotic or necrotic cells (PI positive). Transfected (stealth siRNA) and untransfected cells were washed twice with PBS, trypsinized and washed again with PBS. Cells were re-suspended in binding buffer (10 mM HEPES+10 mM NaOH−pH 7.4, 140 mM NaCl, 2.5 mM CaCl 2 ) at a density of 0.5-1×10 6 cell/mL. To the 100 μL of cell suspension, 3 μl of Annexin V FITC (B.D. Pharmingen) and 10 μL of PI (10 μg/mL) was added and gently vortexed. The cells were incubated at room temperature for 15 min in the dark. To each of the samples, 400 μL of binding buffer was added and placed on ice. Flow cytometric measurements were carried using a FACS caliber flow cytometer (Becton and Dickinson, USA). Green fluorescence due to Annexin V-FITC was collected on the FL1 channel and red fluorescence due to PI was collected on the FL2 channel on a log scale. A minimum of 10,000 cells per sample was acquired and analyzed using CellQuest software (Becton and Dickinson).
[0114] The percentage of Annexin V positive-negative and PI positive-negative cells was estimated by gating the cell population. A375 untreated or Scrambled stealth siRNA-treated cells showed minimum annexin positive cells 48 hours after transfection ( FIG. 5C ). The fraction of annexin positive cells with 6 nM of stealth siRNA was 9%. This was increased to 26% at 12 nM and 53% when 18 nM of Stealth siRNA used for transfection. Interestingly, no major differences were observed in propidium iodide positive cells indicating that the knockdown of SPRY4-IT1 induces cell death primarily through apoptosis, not necrosis. The effect of SPRY4-IT1 knockdown on the invasion of A375 melanoma cells was also examined ( FIGS. 5D & 5E ).
Example 7
SPRY4-IT1 Inhibition Effects Cell Invasion
Invasion Assays
[0115] BD BioCoat™ growth factor reduced insert plates (Matrigel™ Invasion Chamber 12 well plates) were prepared by rehydrating the BD Matrigel™ matrix coating in the inserts with 0.5 mL of serum-free complete Tu media for 2 h at 37° C. The re-hydration solution was carefully removed from the inserts, 500 μL complete Tu (2% FBS) was added to the lower wells of the plate. 1×10 4 transfected and untransfected cells suspended in 500 μL of serum-free complete Tu media was added to the top of each insert well. Invasion assay plates were incubated for 48 h at 37° C. Following incubation, the non-invading cells were removed by scrubbing the upper surface of the insert. The cells on the lower surface of the insert were stained with crystal violet and each trans-well membrane mounted on a microscope slide for visualization and analysis. The slides were scanned in Scanscope and the number of cells migrating was counted using Aperio software (Aperio Technologies). Data are expressed as the percent invasion through the membrane relative to the migration through the control membrane.
[0116] The results of the invasion assay demonstrate that knock-down of SPRY4-IT1 inhibits melanoma cell invasion by greater than 60% at 6 nM of Stealth siRNA and greater than 80% at 12 and 18 nM. This invasion defect is significant, even accounting for defects due to the loss of cell viability (>80% invasion defect at 12 and 18 nM Stealth siRNA with only a 50% loss of cell viability) (see FIGS. 5D and 5E ).
Example 8
SPRY4-IT1-Induced Proliferation, Invasion, and Multinucleation of Melanocytes is Due to Modulation of Cancer-Related Target Genes
[0117] To confirm that modulation of cancer-related target genes such as DPP-IV, TNFRSF25, MCM2, CDK1, CDC20, XIAP, and Livin, results in the SPRY4-IT1-induced increase in cell proliferation, invasion, and multinucleation described in the examples above, RNA-FISH analysis was first performed as described in Example 5, supra, to detect expression of SPRY4-IT1 in cells infected with the lentiviral vector (control) and the lenti-SPRY4-IT1 vector in melanocytes. The results are shown in FIG. 15 , and show GFP expression as a control to indicate that the lentiviral vector has successfully incorporated into the genome. Intense nuclear foci indicate the presence of the longer (743 bp) version of the unprocessed SPRY4-IT1.
[0118] As shown in FIG. 16 , ectopic expression of SPRY4-IT1 increases proliferation in the melanocytes engineered to ectopically express SPRY4-IT1 when compared to cells expressing empty vector. Further, the proliferating cells have been shown to increase in size and become multinucleated, as shown in FIG. 17 .
[0119] Using the methodology described above in Example 3, the RNA and protein content was analyzed using qRT-PCR and protein microarrays to identify the modulated genes. The proto-array data showed that expression of DPP-IV and Trail R2/DR5 were highly downregulated, and Hsp60, Hsp70, Livin, and XIAP were upregulated by enforced SPRY4-IT1 expression in melanocytes. DPP-IV was previously shown to be downregulated in human melanoma, and also suppresses IL-2 production and T-cell proliferation. In the qRT-PCR array, TNFRSF25 was confirmed as being downregulated, and Ki-67, CDK1, CDC20, MCM2, MCM3, MCM4, and MCM5 were highly upregulated, as shown in FIG. 18 . Further, cell migration was shown in MC/LAK cells after four days in culture, but not by control MC/LDGP cells. Collectively, these data confirm the direct involvement of SPRY4-IT1 in melanoma development, and further confirm the a set of target genes implicated in cell proliferation and invasion.
[0120] Staining of SPRY4-IT1-expressing MC/LAK cells and vector-only MC/LDGP cells revealed that only the SPRY4-IT1 cells expressed Ki-67, confirming the results from the qRT-PCR array as shown in FIG. 24 , and consistent with the higher proliferation of SPRY4-IT1-expressing cells. FIG. 24 shows staining in melanocytes expressing SPRY4-IT1 as compared to cells expressing empty vector. Expression of Ki-67 is indicated in the top row. There is little or no expression of Ki-67 in MC/LDGP control cells, but high expression in MC/LAK cells and in the melanoma cell line A375, which was used as a positive control. This confirms the qRT-PCR results shown in FIG. 18 .
[0121] In order to still further confirm that manipulation of target genes may reverse the melanoma-like phenotype observed in MC/LAK cells, SPRY4-IT1-expressing melanocytes are modified using shRNA to create knockdowns of MCM2, CDK1, CDC20, XIAP, and Livin. All lenti-shRNA premade constructs are purchased from Open-Biosystems. The final lentiviral packaging and cell line production is completed at the functional genomics core laboratory at Sanford Burnham Medical Research Institute. Except DPP-IV and TNFRSF25, all genes will be knocked down with lentiviral shRNA. Since these two genes are downregulated in human melanoma, DPP-IV and TNFRSF25 constructs are separately synthesized to over-express these genes in MC/LAK cells. The SPRY4-IT1-expressing melanocyte cell lines engineered to over- and under-express the target genes are subjected to several assays:
[0122] First, the invasiveness and migration of transfected melanocytes are assayed by a modified form of the standard Boyden chamber assay (described by Kleinman, H. K., and Jacob, K., Invasion Assays , Curr. Protoc. Cell Biol., 2001), in which cell invasion by MC/LAK cells is compared to vector-only cells, MC/LDGP after culturing for four days, the long culture period taking into account the slow growth rate of melanocytes compared to melanoma cells.
[0123] In addition to standard invasion assays, Q3DM high throughput microscopy and invasion assay (HTM-IA) is also performed to quantify cell invasion. This technique, developed by Vala Scientific Corporation automated cell imaging team, allows for direct visualization and quantification of cell invasiveness. MTT and BrdU incorporation assays (described in Mosmann, T., Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays , J. Immunol. Methods, 1983, 65(1-2), 55-63) (MTT Cell Proliferation Kit I, Roche) are then performed to assess proliferation and viability of target modulated SPRY4-IT1-expressing cells. Colony formation is measured in vitro by soft agar assays.
[0124] Further, an in vitro wound healing assay is performed to assess cell migration. First, the cells are seeded on MatTek 1.5 mm tissue culture dishes and incubated until 90-95% confluent. The cell monolayers are scratched with a pipette tip across the entire diameter of the dish, and the dishes rinsed extensively with media to remove all cellular debris. The surface area is quantified immediately after wounding, and again at 20-minute intervals for up to 24 hours, using a Nikon Bio Station inverted microscope. The extent of wound closure is determined by calculating the ratio of the surface area between the remaining wound edges for each time point to the surface area of the initial wound. The data are presented as the percentage of wound closure relative to the control conditions for each experiment. The surface area is calculated using NIS Elements software, and each assay is performed in triplicate.
[0125] To confirm that SPRY-IT1 and its target genes induce apoptosis, cells are assayed using the standard Terminal dUTP Nicked-End Labeling (TUNEL) assay, as described in Gavrieli et al., Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation , J. Cell Biol., 1992, 119(3), 493-501. To examine necrosis, membrane permeation is measured by the exclusion of Trypan Blue. Caspase 3/7 activity is also used to determine apoptosis. DEV-Dase Caspase 3/7 activity is detected using the caspase Glo 3/7 Assay kit (Promega). The Guava cell cycle assay is used to measure the distribution of cells in the G0/G1, S, and G2/M phases of the cell cycle, which identifies an effect of SPRY4-IT1 and its target gene expression on melanocyte cell division. The assay uses propidiumiodide (PI) to stain S phase DNA, which results in increased fluorescence intensity. For the controls, melanocytes carrying empty vector are used.
[0126] The collective results of these assays demonstrate that not only is a set of SPRY4-IT1 targets responsible for proliferation, invasion, and multinucleation, but, importantly, that manipulation of these same target genes may reverse this melanoma-like phenotype observed in MC/LAK cells
Example 9
SPRY4-IT1 Functions Through Interactions with Protein/RNA Partners
[0127] To confirm that SPRY4-IT1 functions through interactions with proteins and/or RNA partners, the SPRY4-IT1 regulatory region is first characterized to identify its transcriptional regulation and the molecular mechanism of SPRY4-IT1 processing, RNA decay and trafficking.
[0128] To identify the promoter elements of SPRY4-IT1, a construct was made as depicted in FIG. 19 . First, the SPRY4-IT1 upstream region (1421 bp) was cloned in front of a luciferase reporter gene measured the luciferase activity. The results as shown in FIG. 20 demonstrate that the upstream sequence does contain promoter activity. Further, a vector has been constructed that contains the entire intron one (4588 bp) of the SPRY4 gene (containing the entire SPRY4-IT1 gene) to determine if downstream regulatory elements are necessary for expression. A 3′ probe of SEQ ID NO:3 and a 5′ probe having the sequence GCCTTTTGGGAGGCCAAGGTAGGC (SEQ ID NO:5) were designed for RNA-FISH analysis, and results of this assay demonstrates that the 600 bp cytoplasmic version of the RNA is excised from the 743 bp full length transcript. 5′-RACE reactions (FirstChoice RLM kit, Lifetechnologies) to identify the location of the cleavage. To identify the decay rate, melanoma cells (A375) were incubated with α-amanitin, an RNA polymerase II inhibitor (irreversible inhibition in tissue culture cells at 50 μg/ml). The expression of SPRY4-IT1 was then measured by qRT-PCR and Northern blotting using the protocols described above after 3, 6, 12, and 24 hours of treatment. For the positive control, a probe specific to mascRNA, a small RNA spliced from MALAT1 ncRNA, which has the sequence GATGCTGGTGGTTGGCACTCCTGGCATTTTCCAGGACGGGGTTGAAATCCCTGCGGCGTC (SEQ ID NO:6) and has been shown to decay during a 12 hour treatment with α-amanitin. As shown in FIG. 21 , 80% of SPR4-IT1 transcript was decayed in the first three hours, which is faster than its host gene SPRY4, which has a 40% decay, for the same period in melanoma cell line A375. This indicates that downstream regulatory elements are necessary for expression.
Protein Partners
[0129] To characterize SPRY4-IT1-interacting protein partners, RNA co-immunoprecipitation (RIP) experiments were performed to capture proteins that specifically bind to SPRY4-IT1, and then to characterize the associated proteins by mass spectrometry (MS). A 25-bp complementary sequence to SPRY4-IT1 and having the sequence TTAATAGGCCTTGGAATCAGAAAGC (SEQ ID NO:7) was constructed utilizing a locked nucleic acid (LNA) backbone and a 5′-biotin label. This probe was used as bait to pull down SPRY4-IT1 RNA from melanoma cell lysates, along with any associated molecules. A control probe was designed complementary to the test probe sequence and having the sequence GCTTTCTGATTCCAAGGCCTATTAA (SEQ ID NO:8). The RNA-protein complex was captured on streptavidin columns. RNA was isolated from the pull-down complexes and the amount of SPRY4-IT1 attached to the complex was verified by qRT-PCR. The RNA-protein complex was subjected to LTQ Orbitrap Velos mass spectrometry for further analysis. Table 1 depicts the candidate proteins identified by LTQ Orbitrap Velos mass spectrometry. Two of the proteins with the highest binding affinity are astacin-like metalloendopeptidase (ASTL) and phosphatidate phosphatase (LPIN2), with 372 spectral counts (indicative of protein abundance) for ASTL and 83 counts for LPIN2. Neither protein was detected in the control sample, suggesting these proteins may be relevant to the function of SPRY4-IT1 in melanoma. This confirms that, not only does SPRY4-IT1 function with the assistance of protein partners with high binding affinity, but those proteins have been narrowed to a group delineated below in Table 1:
[0000]
TABLE 1
Detectable Spectral
counts from the LTQ
Protein
Orbitrap Velos Mass
Name
Spectrometer
GPR37
7
RPLP1
2
IGF2BP1
2
RPS3
2
RPS6
2
LPIN2
83
ALB
3
HNRNPCL1
3
TRAP1
13
TUBB2B
11
HSPE1
2
DPYSL2
2
RPL24
2
IGH
9
ASTL
372
Example 10
SPRY4-IT1 Expression in Prostate Cancer Cells
[0130] In order to confirm expression and co-localization of SPRY4-IT1 with protein partners in PC-3 prostate cancer cells, RNA-FISH assays were performed as follows: locked nucleic acid (LNA)-modified probes for human lncRNA SPRY4-IT1 having the sequence of SEQ ID NO:3 and a negative/Scramble control having the sequence of SEQ ID NO:4 were used for RNA in situ hybridization. In situ hybridization was performed using the RiboMap in situ hybridization kit (Ventana Medical Systems Inc) on a Ventana machine. The cell suspension diluted to 10,000 cells per 100 μL was pipetted into clonal rings on the autoclaved glass slides. The following day, the clonal rings were removed; slides were washed in PBS and fixed in 4% paraformaldehyde and 5% acetic acid. After acid treatment using hydrochloride-based RiboClear reagent (Ventana Medical Systems) for 10 min at 37° C., the slides were treated with the ready-to-use protease 3 reagent. The cells were hybridized with the antisense LNA riboprobe (40 nM) using RiboHybe hybridization buffer (Ventana Medical Systems) for 2 h at 58° C. after an initial denaturing prehybridization step for 4 min at 80° C. Next, the slides were subjected to a low-stringency wash with 0.1×SSC (Ventana Medical Systems) for 4 min at 60° C., and then two further washing steps with 1×SSC for 4 min at 60° C. These slides were fixed in RiboFix and counterstained with 4′-6′diamidino-2-phenylindole (DAPI), in an antifade reagent (Ventana), fluorescein isothiocyanate (FITC), and Alexa 546. The images were acquired using a Nikon AIR VAAS laser point- and resonant-scanning confocal microscope equipped with a single photon Ar-ion laser at 60× with 4× zoom. The images of each stain were superimposed into a merged image to show co-localization.
[0131] Three sets of images resulted. In the first, images of DAPI-stained nuclei, FITC-stained SPRY4-IT1, and Alexa 546-stained Anti-L7a (to show localization of endogenous ribosomes), were superimposed. In the second, images of DAPI-stained nuclei, FITC-stained SPRY4-IT1, and Alexa 546-stained Phalloidin were superimposed. In the last set, images of DAPI-stained nuclei, FITC-stained SPRY4-IT1, and Alexa 546-stained anti-rck/p54 (associated with mRNA decay) were superimposed. The three sets show not only the cytoplasmic location of SPRY4-IT1, but also demonstrate a pronounced pattern of colocalization of SPRY4-IT1 with endogenous ribosomes and L7a, actin as shown by phalloidin, and anti-rck/p54, the latter of which is a proto-oncogene that has been shown to be overexpressed in tumor tissue and likely regulates mRNA decay. The high degree of colocalization shown in the superimposed images confirms a high likelihood of biological interaction between SPRY4-IT1 and the protein partners associated with prostate cancer.
[0132] The contents of the articles, patents, and patent applications, and all other documents and electronically available information mentioned or cited herein, are hereby incorporated by reference in their entirety to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. Applicants reserve the right to physically incorporate into this application any and all materials and information from any such articles, patents, patent applications, or other physical and electronic documents.
[0133] The inventions illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the inventions embodied therein herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention.
[0134] The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.
[0135] Other embodiments are within the following claims. In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group. | Provided herein are methods for the diagnosis of cancer by comparison of a quantification of long non-coding RNA SPRY4-IT1 with the same measurement taken in a reference sample from a healthy patient. Further provided herein are methods of anticipating the likelihood that such a disease will develop, and methods of treatment in the event of such development. | 0 |
BACKGROUND OF THE INVENTION
This invention relates generally to the support of percussion devices, as for example cowbells; and more particularly relates to cushioning and adjustable cushioning of such devices.
When percussionists use drum sticks to forcibly strike cowbells that are rigidly supported, there is considerable shock effect transmitted back to the percussionist's hand and wrist. This reaction “hardness” differs substantially from the lower level impact effect created when a drum head is struck. There is need to alleviate at least in part such shock effect, which can be increasingly undesirable when the cowbell is struck with great force. Also, there is need for adjusting such created reaction effect when the cowbell is struck, i.e. for “tuning” of the cowbell.
SUMMARY OF THE INVENTION
It is a major object of the invention to provide a solution to the above problem, which meets the percussionist's needs. Basically, the invention is embodied in the provision of a cushioned percussion device that comprises:
a) a projecting support for the device,
b) a pivot for the support, and
c) spring structure located to yieldably resist pivoting of the support.
As will be seen, the spring structure may advantageously include a first spring element to resist pivoting in one direction, and a second spring element to resist pivoting in the opposite direction. A carrier typically carries that structure offset from the pivot and offset from a clamp or holder holding the percussion instrument in a position to be struck.
It is another object to provide an adjuster to adjust the tension of the spring structure, for controlling the yieldable resistance to pivoting of the support. As will be seen, two adjustable spring elements or portions may be provided to adjust yieldable resistance to pivoting, in two directions.
Yet another object includes provision of support structure including a strut yieldably supporting a cowbell lower portion; and a holder or clamp adjustably connecting the cowbell lower portion to the strut in spaced relation to the spring or springs, to enable adjustment of the clamp and cowbell lower portion toward or away from the spring or springs.
Accordingly, the cowbell cushioned support apparatus may be “tuned” at up to three locations, to optimize the selectability of cushioned support for the cowbell, to individually suit requirements of different percussionists.
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which:
DRAWING DESCRIPTION
FIG. 1 is an elevation showing one preferred form of apparatus;
FIG. 2 is a cross-section taken on lines 2 — 2 of FIG. 1;
FIG. 3 is a plan view taken on lines 3 — 3 of FIG. 2;
FIG. 4 is a section taken on lines 4 — 4 of FIG. 2;
FIG. 5 is a section taken on lines 5 — 5 of FIG. 2; and
FIG. 6 is an elevation like FIG. 1, but showing a modified form.
DETAILED DESCRIPTION
In the drawings a percussion instrument or device is shown at 10 , and may take the form of a cowbell. It has a lower wall portion 11 , and upwardly diverging walls 12 . The cowbell is to be forcefully struck as by a drum beater or stick 13 , during a performance or during practice. Upper rim 12 a can also be struck.
In accordance with the invention, support structure is provided yieldably and resiliently supporting the cowbell lower portion 11 to enable the cowbell to bodily deflect when struck. The illustrated example shows such support structure to include a projecting support such as a strut 15 connected to the cowbell lower portion, as for example at 16 . That connection may advantageously include a clamp 17 having an upper part 17 a and a lower part 17 b at opposite sides of the strut, and which may be loosened to allow adjustment shifting of the cowbell lengthwise of the strut, toward or away from cushioning spring structure 18 . The clamp 17 may then be tightened, as on a threaded part 17 c . Such adjustment shifting facilitates adjustment of stiffness of cowbell deflection, when struck, to suit the requirements of the percussionist. The strut 15 may comprise a metal rod, which is knurled as shown at 15 a to facilitate non-slip connection of the clamp to the rod. A clamp adjuster is seen at 17 d.
The spring structure 18 and strut 15 may be carried by a carrier, as for example a second strut or rod 20 having a projection 20 a . Strut 15 may have connection to rod 20 , as at a pivot 22 , for allowing the cowbell to bodily move up and down. The spring structure is carried for resiliently and yieldably resisting such bodily movement of the cowbell.
In the example, a first spring or spring portion 18 a is positioned to resist downward pivoting of the strut 15 ; and a second spring or spring portion 18 b is positioned to resist upward pivoting of the strut 15 . Spring portion 18 a is shown as located below strut 15 and spring portion 18 b above strut 15 ; however, the spring portions may have other positions.
In accordance with a further feature of the invention, the stiffness of one or both of the spring portions may be adjusted, to the requirements of the percussionist, whereby the stiffness of cowbell deflection is adjustable. In the example, a first adjuster 25 is provided to adjust the tension of the first spring portion 18 a , and a second adjuster 26 is provided to adjust the tension of the second spring portion 18 b . The first adjuster may have threaded connection to one end of a spring positioner 27 , whereby when rotated at 25 a , the spring portion 18 a is controllably compressed; and the second adjuster may have threaded connection to the opposite end of positioner 28 , whereby when rotated at 26 a , the spring portion 18 b is controllably compressed.
The spring portion 18 a is compressed between adjuster 25 and a locater or connector 30 ; and the spring portion 18 b is compressed between adjuster 26 and connector 30 . That connector transmits spring force to the strut 15 , at location 31 , and the latter may include a pivot connection to the strut. See also guide pin 40 , thread connected to 25 and 26 , and tubular housing 41 for 25 , 26 and 30 . Set screws 42 when tightened fix the selected adjustment. Projection 20 a carries housing 41 .
In operation, when the cowbell is heavily struck, as by force F, the strut 15 is pivoted downwardly, and coiled spring portion 18 a is momentarily compressed. As the strut 15 thereafter pivots or returns upwardly, upper spring portion 18 b is momentarily compressed; and the compressions of the two spring portions can be adjusted to adjust the stiffness of deflection of the cow bell, during play, to meet the requirements of the percussionist.
Carrier rod 20 may be suitably connected to an upright stand, such as a cymbals stand 44 .
In FIG. 6 the elements are generally the same as in FIG. 1, except for the following: the carrier pin 40 for the springs has pivotal connection at 60 to the strut 15 ; coil spring 18 a is compressed between an angled region 63 of rod 20 and a nut 61 ; and coil spring 18 b is compressed between angled locater region 63 and a nut 62 . The two nuts are threaded on the pin 40 , for adjustment to adjust the tension of the two springs, which control the yieldability of the cow bell when struck as by drum stick 13 . Such yieldability is indicated by pivoting of the strut 15 about pivot 22 . Nuts 61 and 62 are one form of pushers. | The cushioned percussion device, comprising in combination, a projecting support for the device; a pivot for said support, and spring structure located to yieldably resist pivoting of the support. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/986,865 filed Nov. 9, 2007, the contents of which are incorporated herein by reference thereto.
BACKGROUND
[0002] Various embodiments of the present invention relate to a pneumatically powered pole saw.
[0003] Manually operated pole saws require an operator to manually push and pull a long pole back and forth in order to move a saw blade attached to the end of the pole, thereby cutting tree limbs with the attached saw blade. These pole saws rely entirely upon the operator force the necessary forces to be applied to the cutting blade or saw blade of the pole saw. Accordingly, and as the operator tires the efficiency of the cutting operation is reduced.
[0004] Accordingly, it is desirable to provide a powered pole saw having a means for efficiently converting stored energy into kinetic energy wherein the saw blade of the pole saw is actuated.
SUMMARY OF THE INVENTION
[0005] A pneumatically powered pole saw and method of operating is provided. Exemplary embodiments are directed to a pneumatically powered pole saw, comprising: an extendable pole; a head member secured to the extendable pole; a cutting blade movably mounted to the head member; a piston linked to the cutting blade, the piston being slidably received within a piston chamber of the head member; a reciprocating valve disposed in the head member, the reciprocating valve being configured for movement between a first position and a second position wherein the reciprocating valve releases a portion of a source of compressed gas into the piston chamber on one side of the piston when the reciprocating valve is in the first position causing the cutting blade to move in a first cutting direction towards a limit of travel in the first cutting direction and a first check valve provides fluid communication to the piston chamber on another side of the piston causing the reciprocating valve to move from the first position towards the second position, when the cutting blade reaches the limit of travel in the first direction, the reciprocating valve releases another portion of the source of compressed gas into the piston chamber on the another side of the piston when the reciprocating valve is in the second position causing the cutting blade to move in a second cutting direction opposite to the first cutting direction and towards a limit of travel in the second cutting direction and a second check valve provides fluid communication to the piston chamber on the one side of the piston, the reciprocating valve moving from the second position towards the first position when the cutting blade reaches a limit of travel in the second direction.
[0006] The above-described and other features are appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.
DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of a pneumatically powered pole saw constructed in accordance with an exemplary embodiment of the present invention;
[0008] FIG. 1A is a perspective view of a pneumatically powered pole saw constructed in accordance with an alternative exemplary embodiment of the present invention;
[0009] FIGS. 1B-D illustrate saw blades for use in various exemplary embodiments of the present invention;
[0010] FIG. 2 is a side view of a pneumatically powered pole saw constructed in accordance with an exemplary embodiment of the present invention;
[0011] FIG. 3 is a view along lines 3 - 3 of FIG. 2 ;
[0012] FIG. 4 is a cross-sectional view along lines 4 - 4 of FIG. 3 ;
[0013] FIGS. 5A-5D are schematic illustrations of exemplary embodiments of the present invention;
[0014] FIG. 6 is a view illustrating one exemplary embodiment of the present invention;
[0015] FIG. 7 is a view illustrating another exemplary embodiment of the present invention;
[0016] FIG. 8 is a view illustrating an exemplary embodiment of the present invention;
[0017] FIGS. 9A-9B are schematic illustrations of alternative embodiments of the present invention;
[0018] FIGS. 10A-10B are enlarged views of a reciprocating valve shown in FIGS. 9A-9B ; and
[0019] FIGS. 11A-11B are enlarged views showing operational positions of the check valves shown in FIGS. 9A-9B .
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0020] In accordance with exemplary embodiments of the present invention, a pneumatically powered pole saw and method for operating the pole saw is disclosed. In an exemplary embodiment the pneumatically powered pole saw will comprise a source of compressed gas for use in driving the blade of the pole saw.
[0021] Referring now to FIGS. 1-5 , a pneumatically powered pole saw 10 constructed in accordance with an exemplary embodiment of the present invention is illustrated. Pneumatically powered pole saw 10 has a cutting blade 12 movably mounted to a head member 14 of the pneumatically powered pole saw. Head member 14 further comprises a cylinder 16 configured to sildably receive a piston 18 therein. In accordance with an exemplary embodiment of the present invention piston 18 has at least one O-ring or sealing member that allows the piston to slide within the cylinder while also preventing or limiting fluid communication therethrough (e.g., maintaining or preventing fluids or gases on one side of the piston from passing around the piston to another side of the piston). Piston 18 is secured to a rod 20 that is secured to cutting blade 12 via a mount 22 . Rod 20 passes through a sealed end of the housing wherein the rod is allowed to slide in and out without the release of the gases in the chamber through the opening the rod slides in. Mount 22 is configured to removably secure the cutting blade to the mount thus allowing removal and replacement of the cutting blade as it becomes worn, damaged or dulled. In one exemplary embodiment, the mount 22 has a pair of rollers 24 slidably received within a pair of complimentary channels or slots 26 disposed in a frame portion 28 of the head member. Rollers 24 allow the mount and the cutting blade to slide within a range of movement on the head member.
[0022] In one non-limiting exemplary embodiment, the head member further comprises a roller 30 rotatably mounted to the frame portion of the head member, the roller having a groove 32 configured to receive a non-toothed portion 34 of the cutting blade within the groove of the roller. Accordingly, roller 30 provides a means for supporting the cutting blade as it reciprocates within a range of motion on the head member.
[0023] In order to cause the cutting blade to traverse back and forth between a first position (e.g., cutting blade fully extended away from a distal end of the head member) and a second position (e.g., cutting blade fully retracted into the distal end of the head member) a source of compressed gas 36 is in selective fluid communication with a chamber ( 38 , 40 ) at either side of the piston to cause movement of the piston in the chamber, wherein movement of the piston causes movement oft he cutting blade by moving the rod and the mount. It being understood that size of chambers 38 and 40 vary accordingly with the movement of the piston 18 . In one non-limiting exemplary embodiment, the source of compressed gas is self-contained reservoir of carbon dioxide. Of course, other suitable types of compressed gas are considered to be within the scope of exemplary embodiments oft he present invention. In another exemplary embodiment, the source of compressed gas is provided by a reservoir fluidly coupled to a compressor 29 , which may be a stand alone device or a wearable unit.
[0024] In order to provide fluid communication between the source of compressed gas and chamber 38 a first valve 42 is provided to allow selective fluid communication between the source of compress gas and chamber 38 via a conduit 44 . First valve 42 is configured to allow fluid communication between the source of compressed gas and chamber 38 when the first valve is in an open position. Alternatively, and when the first valve is in a closed position chamber 38 is in fluid communication with atmosphere so that the gas in chamber 38 may be released to allow the cutting blade to travel to the first position. This is also provided by first valve 42 and conduit 44 . Accordingly, and when the first valve is closed, chamber 38 via conduit 44 and first valve 42 allow the fluid in chamber 38 to be released into the atmosphere.
[0025] In order to provide fluid communication between the source of compressed gas and chamber 40 a second valve 46 is provided to allow selective fluid communication between the source of compress gas and chamber 40 via a conduit 48 . Second valve 46 is configured to allow fluid communication between the source of compressed gas and chamber 40 when the second valve is in an open position. Alternatively, and when the second valve is in a closed position chamber 40 is in fluid communication with atmosphere so that the gas in chamber 40 may be released to allow the cutting blade to travel to the second position. This is also provided by second valve 46 and conduit 48 . Accordingly, and when the second valve is closed, chamber 40 via conduit 48 and second valve 46 allow the fluid in chamber 40 to be released into the atmosphere.
[0026] In accordance with an exemplary embodiment of the present invention and in order to move the cutting blade to the first position the first valve is closed (e.g., gas vented from chamber 38 ) and the second valve is open (e.g., gas supplied from source to chamber 40 ). Similarly and in order to move the cutting blade to the second position the first valve is open (e.g., gas supplied from source to chamber 38 ) and the second valve is closed (e.g., gas vented from chamber 40 ).
[0027] In order to provide the opening and closing of valves 42 and 46 a slider 50 is movably received within head member 14 wherein movement of the slider causes the first valve and the second valve to open and close. In order to effect the movement of slider 50 a rod portion 52 of the slider has a pair of stops 54 and 56 wherein a portion 58 of the mount 22 is slidably received upon the rod portion 52 . As the cutting blade traverses towards the first position the portion 58 will contact stop 54 and cause first valve 42 to open and second valve 46 to close thus, the cutting blade will then traverse towards the second position wherein the portion 58 will contact stop 56 and cause first valve 42 to close and second valve 46 to open thus, the cutting blade will then traverse towards the first position. This reciprocal movement of the cutting blade will continue until the source of gas is no longer fluidly coupled to the first valve and the second valve.
[0028] As illustrated in FIG. 4 , the slider is slidably mounted above a cover plate 60 that is configured to allow slider 50 to open and close the first and second valves. Moreover, cover plate 60 is configured to prevent excessive wear from being caused by the reciprocal movement of the slider. In an alternative exemplary embodiment, the pneumatically powered pole saw is constructed without a cover plate (See FIGS. 5A-5D ).
[0029] In order to provide fluid communication between the source of inlet or compressed gas 36 and the first valve and the second valve a control valve 62 is configured to provide fluid communication between the source of inlet or compressed gas 36 and the first valve and the second valve via conduits 64 between valve 42 and valve 46 and a conduit 68 between source of compressed gas 36 and control valve 62 . In accordance with an exemplary embodiment of the present invention control valve 62 is in or proximate to head member 14 while conduit 68 extends to the source of compressed gas, which is disposed at an opposite end of a pole the head member is secured to.
[0030] Referring now to FIGS. 5A-5D operation of an exemplary embodiment of the present invention is illustrated. FIG. 5A illustrates the saw blade traveling in the direction of arrow 51 . During this mode of operation and in the illustrated configuration of FIG. 5A valve 46 is open and compressed gas is being released into chamber 40 while the gas of chamber 38 is being released into the atmosphere from a vent of valve 42 thus piston 18 and the saw blade travel in the direction of arrow 51 . It being understood that in order to effect movement in the direction of arrow 51 valve 42 is closed to conduit 64 while valve 46 is open to conduit 64 since a first feature 53 of the slider is positioned to receive a spring biased member 55 of valve 42 thus, causing conduit 64 to be closed to chamber 38 while chamber 38 is open to atmosphere via a vent 57 of valve 42 .
[0031] In accordance with an exemplary embodiment of the present invention member 55 is biased generally into the direction of slider 50 such that when member 55 is received into feature 53 of slider 50 conduit 64 is closed to chamber 38 and vent 57 is open releasing the gas of chamber 38 while the saw blade travels in the direction of arrow 51 .
[0032] Movement of the saw blade in the direction of arrow 51 continues until portion 58 contacts stop 54 ( FIG. 5B ) causing the slider 50 to translate into the position of FIG. 5B wherein the feature 53 is no longer aligned with member 55 and the same is depressed into valve 42 causing conduit 64 to be in fluid communication with chamber 38 via valve 42 and conduit 44 . At this position, the vent 57 of valve 42 is closed and the piston and saw blade will begin to travel in a direction opposite to arrow 51 . Moreover, and at this position valve 46 is closed and the gas of chamber 40 is being released into the atmosphere from a vent of valve 46 . It being understood that valve 46 is closed to conduit 64 while valve 42 is open to conduit 64 since a second feature 59 of the slider is no longer positioned to receive a spring biased member 61 of valve 46 thus, causing conduit 64 to be closed to chamber 40 while chamber 40 is open to atmosphere via a vent 63 of valve 46 .
[0033] In accordance with an exemplary embodiment of the present invention member 61 is biased generally into the direction of slider 50 such that when member 61 is received into feature 59 of slider 50 conduit 64 is closed to chamber 40 and vent 63 is open releasing the gas of chamber 40 while the saw blade travels in the direction opposite of arrow 51 . Conversely, and when member 61 is not received into feature 59 of slider 50 ( FIG. 5A ) conduit 64 is open to chamber 40 and vent 63 is closed and the saw blade and piston travel in the direction of arrow 51 .
[0034] Movement of the saw blade in the direction opposite of arrow 51 continues ( FIG. 5C ) until portion 58 now contacts stop 56 ( FIG. 5D ) causing the slider 50 to translate back into the position of FIG. 5A wherein feature 53 is aligned with member 55 and feature 59 is not aligned with member 61 causing conduit 64 to be in fluid communication with chamber 40 via valve 46 and conduit 48 . At this position, the vent 57 of valve 42 is open and the piston and saw blade will begin to travel in the direction of arrow 51 . It being understood that valve 46 is open to conduit 64 while valve 42 is closed to conduit 64 since the second feature 59 of the slider is no longer positioned to receive spring biased member 61 of valve 46 thus, causing conduit 64 to be open to chamber 40 while chamber 38 is open to atmosphere via vent 57 of valve 42 .
[0035] In accordance with an exemplary embodiment of the present invention, this reciprocal movement of saw blade 12 , piston 18 and slider 50 will continue until the source of compressed gas released into conduit 64 by valve 62 ceases.
[0036] In accordance with an exemplary embodiment and by having the control valve at or proximate to the head member conservation of the gas supply is provided as conduit 68 will traverse through the pole which can be 20 feet or longer thus, and if the pole saw was required to fill or energize conduit 68 with gas each time the pneumatically powered pole saw was activated the source of compressed gas will be depleted quicker. Of course, the pole may be of any length (e.g., 10 feet or shorter, 8 feet or shorter, 6 feet or shorter, etc.). A non-limiting range for the length of the pole may be 5-25 feet. In accordance with an exemplary embodiment conduit 68 is filled with the gas and control valve 62 turns the saw on and off by limiting the amount of gas supplied via source of gas 36 .
[0037] In one non-limiting exemplary embodiment, control valve 62 is an electro mechanical valve activated by a switch 70 disposed at an end of the pneumatically powered pole saw opposite from the cutting blade. In another non-limiting exemplary embodiment, control valve 62 is a pneumatically activated valve wherein a fluid conduit 72 provides fluid communication with the source of compressed gas and switch 70 allows fluid communication between valve 62 and source of compressed gas 36 wherein the compressed gas will open valve 62 and gas will be supplied to valves 42 and 46 . In this embodiment, and in order to conserve the fluid supply of compressed gas 36 conduit 72 is much smaller than conduit 68 and thus only a small amount of gas is wasted each time valve 62 is opened. Furthermore, switch or valve 70 can be operated at a much lower pressure than the pressure passing through conduit 68 and is necessary to manipulate the movement of the piston within the cylinder.
[0038] Referring now to FIG. 6 a pneumatically powered pole saw 10 constructed in accordance with an exemplary embodiment of the present invention is illustrated here a source of compressed gas 36 is a bottle secured to an end of a pole 78 . In this embodiment, conduit 68 and/or conduit 72 traverse the length of pole 78 until they reach control valve 62 , which disposed in or proximate to head portion 14 . Thus, a user 80 activates the pneumatically powered pole saw by manipulating switch 70 and the saw is activated to cut a limb 82 of a tree 84 . Once the desired task is completed, switch 70 is moved to an off position and the remaining gas is eventually released from the head member.
[0039] FIG. 7 illustrates an alternative exemplary embodiment, wherein the source of compressed gas 36 is secured to a wearable belt or harness 86 thus, the individual wears the compressed gas and the same is secured to the conduit 68 of the pole via a flexible conduit 88 . Here the weight of the compressed gas is not on the end of the pole making the same easy to manipulate and use.
[0040] Referring now to FIG. 1A an alternative exemplary embodiment of the present invention is illustrated. Here frame portion 28 further comprises a stop member 120 . In an exemplary embodiment, stop member 120 has a pair of arms 122 and a cross member 124 that define a stop for limb that is being cut by the pole saw. For example, and as the blade is drawn towards the stop the teeth of the blade will engage the limb and apply a downward force to the limb which in turn may cause the head member to be drawn upward or in an opposite direction to the force being applied to the limb as the blade travels down towards the stop member. Accordingly, and in order to impart the cutting force to the limb in a downward stroke of the blade the stop member provides a surface to receive a portion of the limb on as the blade travels downward towards the stop member. Alternatively, and as illustrated by the dashed lines in FIG. 1A , the frame portion 28 is configured to extend past roller 30 and enclose the same within a portion of the frame portion so that limbs being cut or not being cut do not interfere with the movement of roller 32 .
[0041] Referring now to FIGS. 1B-1D alternative configurations of the saw blade are illustrated. FIG. 1B illustrates a straight saw blade wherein a width 130 of the blade from the non-toothed portion 34 and a toothed portion of the blade is essentially the same thickness along an edge 132 that is received within groove 32 of roller 30 . Accordingly, and in this embodiment, the teeth of the blade generally act upon a cutting surface in a linear fashion.
[0042] Alternatively, and referring now to FIG. 1C , the width 130 of the blade from the non-toothed portion 34 and a toothed portion of the blade is not the same thickness along an edge 132 that is received within groove 32 of roller 30 . Accordingly, and in this embodiment, the teeth of the blade generally act upon a cutting surface in a non-linear or curved fashion as the toothed surface also has a curved configuration.
[0043] In yet another alternative, and referring now to FIG. 1D , the width 130 of the blade from the non-toothed portion 34 and a toothed portion of the blade is not the same thickness along an edge 132 that is received within groove 32 of roller 30 . Accordingly, and in this embodiment, the teeth of the blade generally act upon a cutting surface in a non-linear fashion as the saw blade is reciprocated within a range of motion and the teeth are acting upon a cutting surface.
[0044] In addition, and in accordance with one non-limiting exemplary embodiment of the present invention the stroke of the saw blade is approximately 4 inches which has been found to be suitable for tree limb cutting operations. Of course, strokes greater or less than 4 inches are considered to be within the scope of exemplary embodiments of the present invention.
[0045] In an alternative exemplary embodiment, the piston may be spring biased into one of the positions illustrated in FIGS. 5A-5D such that one of the valves 42 or 46 is open at an initial starting point and movement to the next position will be caused by the piston overcoming the spring force as well as the gas pressure on one side of the piston. In another exemplary embodiment, a spring biasing member may be positioned on either side of the piston wherein one spring biasing force is greater than the other to maintain one of the positions illustrated in FIGS. 5A-5D such that one of the valves 42 or 46 is open at an initial starting point.
[0046] Referring now to FIGS. 9A-11B , a pneumatically powered pole saw 10 constructed in accordance with an alternative embodiment of the present invention is illustrated. Here, referring to FIGS. 9B and 10B and in order to provide fluid communication between the source of compressed gas and chamber 40 a reciprocating valve 132 is provided to allow selective fluid communication between the source of compressed gas and chamber 40 via a conduit 134 . In one non-limiting exemplary embodiment the reciprocating valve is a Humphrey Products TAC Valve (See FIGS. 10A and 10B ). One non-limiting description of a Humphrey Valve is found in U.S. Pat. No. 6,488,050 the contents of which are incorporated herein by reference thereto. When the reciprocating valve is in a first position (See FIGS. 9B and 10B ), a first outlet 136 of reciprocating valve is in fluid communication with a fluid inlet 138 of reciprocating valve which is in fluid communication with an inlet conduit 139 which is in fluid communication with the source of compressed gas to allow fluid communication between the source of compressed gas and chamber 40 .
[0047] Alternatively, and as illustrated by the dashed lines in FIGS. 9A as well as in FIGS. 10A and 11A , when the reciprocating valve is in a second position, the first outlet 136 restricts fluid communication between the source of compressed gas and chamber 40 and chamber 40 is in fluid communication with the atmosphere so that the gas in chamber 40 may be released via opening a first check valve 140 disposed on conduit 134 to allow the cutting blade to travel to the second position. In still another embodiment, the first check valve is disposed proximate to chamber 40 . Accordingly, and when the reciprocating valve is in the second position, chamber 40 via first check valve 140 allows the fluid in chamber 40 to be released to the atmosphere.
[0048] Referring back to FIGS. 9A and 10A and in order to provide fluid communication between the source of compressed gas and chamber 38 a reciprocating valve 132 is provided to allow selective fluid communication between the source of compressed gas and chamber 38 via a conduit 142 . When the reciprocating valve is in a second position (See FIGS. 9A and 10A ), a second outlet 144 of reciprocating valve is in fluid communication with the fluid inlet 138 of reciprocating valve which is in fluid communication with the inlet conduit 139 which is in fluid communication with the source of compressed gas to allow fluid communication between the source of compressed gas and chamber 38 .
[0049] Alternatively, and as illustrated by the dashed lines in FIG. 9B as well as in FIGS. 10B and 11B , when the reciprocating valve is in a first position, the second outlet 144 restricts fluid communication between the source of compressed gas and chamber 38 and chamber 38 is in fluid communication with the atmosphere so that the gas in chamber 38 may be released via opening a second check valve 146 disposed on conduit 142 to allow the cutting blade to travel to the first position. In one non-limiting exemplary embodiment, the second check valve is disposed proximate to chamber 38 . Accordingly, and when the reciprocating valve is in the first position, chamber 38 via second check valve 146 allows the fluid in chamber 38 to be released to the atmosphere.
[0050] In accordance with an alternative embodiment of the present invention and in order to move the cutting blade in the first cutting direction, the reciprocating valve 132 is in the first position (e.g. gas supplied from source to chamber 40 ) and the second check valve 146 is opened (e.g. gas vented from chamber 38 ). Similarly, and in order to move the cutting blade to the second cutting direction the reciprocating valve 132 is in the second position (e.g. gas supplied from source to chamber 40 ) and the first check valve 140 is opened (gas vented from chamber 40 ).
[0051] In order to provide the movement between the first and second positions of the reciprocating valve 132 an actuator 148 is disposed within the reciprocating valve wherein movement oft he actuator 148 causes the reciprocating valve to move between the first and second positions (See FIGS. 9A-10B ). In order to effect the movement of the actuator an assembly 150 is slidably mounted in the head member. The assembly also has a pair of fixedly secured stops 152 and 154 wherein a portion 156 of the cutting blade is slidably received upon the assembly. As the cutting blade traverses in the first cutting direction the portion 156 of the cutting blade will contact stop 152 and cause the assembly 150 to move and contact the actuator causing movement of the reciprocating valve to the second position causing first check valve 140 to open thus, the cutting blade will then traverse in the second cutting direction wherein portion 156 will contact stop 154 and cause the assembly to move and contact the actuator causing movement oft he reciprocating valve to the first position causing second check valve to open thus, the cutting blade will then traverse to the first cutting position. This reciprocal movement of the cutting blade will continue until the source of gas is no longer fluidly coupled to the inlet 132 of the reciprocating valve.
[0052] As illustrated in FIGS. 9A and 9B , the assembly further comprises a main rod member 158 for slidably receiving the portion 156 of the cutting blade and a pair of contact members 160 and 162 each fixedly secured to the main rod member 158 . Moreover, the actuator comprises a pair of contact sides 164 and 166 (See 10 A and 10 B) associated with the pair of contact members 160 and 162 wherein contact member 160 contacts contact side 164 when the portion 156 of cutting blade makes contact with stop 154 causing assembly to move in the second cutting direction, and similarly, contact member 162 contacts contact side 166 when the portion 156 of cutting blade makes contact with stop 152 causing assembly to move in the first cutting direction. It being understood that the pair of contact members 160 and 162 are not fixedly secured to the contact sides 164 and 166 oft he actuator such that when contact member 160 is in contact with contact side 164 a spaced relationship or gap exists between contact member 162 and contact side 166 . Similarly, when contact member 162 is in contact with contact side 166 a spaced relationship or gap exists between contact member 160 and contact side 164 .
[0053] In one non-limiting alternative embodiment of the present invention a pair of biasing members 153 and 155 disposed proximate to stops 152 and 154 provides portion 156 to be biased in the opposite direction when portion 156 makes contact with stop 152 or 154 . It being understood that biasing members 153 and 155 are disposed on the side opposite to contact surface between portion 156 of and respective stop 152 or 154 . Referring to FIG. 9A , when portion 156 makes contact with stop 152 assembly moves to the first cutting direction and portion 156 is subsequently biased to the second cutting direction due to the force provided by biasing member 153 . Similarly, referring to FIG. 9B , when portion 156 makes contact with stop 154 assembly moves to the second cutting direction and portion 156 is subsequently biased to the first cutting direction due to the force provided by biasing member 155 .
[0054] Referring to FIGS. 9A-11B operation of an alternative embodiment of the present invention is illustrated. It being understood that FIGS. 11A and 11B illustrate check valves 140 and 146 in a venting position ( FIG. 11B ) wherein the gas from the piston chambers 38 , 40 moves the diaphragm 178 and in a supply position ( FIG. 11A ) wherein compressed gas is supplied via inlet 176 and the same moves the diaphragm 178 to cover the valve seat 180 and prevent fluid communication to outlet 184 . In other words the configurations of valve 140 and 146 are similar thus, two figures are used to show the two positions of the two valves each being in selective fluid communication with either side of the piston chamber. It being further understood that outlets 184 of valves 140 and 146 are open to atmosphere to allow for unimpeded movement of the saw blade by the alternating supply of the compressed gas to the piston chambers at either side oft he movable piston. In accordance with an exemplary embodiment, the diaphragm 178 is constructed out of a resilient pliable material such as rubber or equivalents thereof such that the same can be moved by the gas from chambers 38 and 40 or the supply inlet 176 . FIG. 9A illustrates the saw blade moved in the first cutting direction 157 . During the traverse from the second cutting direction (opposite to arrow 157 ) to the first cutting direction reciprocating valve 132 is in the first position (See FIG. 10B ) wherein second check valve 146 is open ( FIG. 11B ) thereby venting gas from chamber 38 to the atmosphere while first outlet 136 is in fluid communication with inlet 138 allowing fluid communication between the source of compressed gas and chamber 40 via check valve 140 ( FIG. 11A ) thus piston 19 and the saw blade travel in the first cutting direction. It being understood that in order to effect movement towards the first cutting direction the second outlet 144 is closed to conduit 142 and the first outlet is in fluid communication with conduit 134 since a first seal 168 is seated within a first seat 170 thereby opening first outlet 136 thus, causing conduit 134 to be in fluid communication with chamber 40 . Similarly, a second seal 172 is unseated from a second seat 174 thereby sealing second outlet 144 thus, causing conduit 146 to be closed to chamber 38 while chamber 38 is open to atmosphere via second check valve 146 (FIG.
[0055] Referring now to FIGS. 9B and 11B , second check valve 146 is in an un-actuated position ( FIG. 11B ) configured to release gas from chamber 38 to the atmosphere when compressed gas is not entering through a conduit inlet 176 thereby causing a diaphragm 178 to not close against a valve seat 180 so that compressed gas from chamber 38 via piston passage 182 may vent directly to the atmosphere through an atmosphere outlet 184 instead of venting through the entire length of conduit 142 . Moreover, the pressure caused by the piston travelling in the direction of arrow 157 from the position in FIG. 9B to the position in FIG. 9A causes the diaphragm 178 in valve 146 to move up to the position illustrated in FIG. 11B . This is particularly advantageous because allowing the compressed gas to vent from chamber 38 more quickly allows less back-pressure to retard the movement of the piston 18 . Similarly, referring to FIGS. 9B and 11A and as the blade travels in a direction opposite to arrow 157 , first check valve 140 is in an actuated position ( FIG. 11A ) configured to supply compressed gas to chamber 40 through the conduit inlet 176 thereby causing diaphragm 178 to close against valve seat 180 and diaphragm 178 has a peripheral configuration so that compressed gas may be supplied to chamber 40 via piston passage 182 and as illustrated by the arrows in FIG. 11A since the compressed gas forces the diaphragm against valve seat 180 .
[0056] In one non-limiting alternative embodiment of the present invention first and second check valves 140 , 146 , are disposed proximate to chambers 40 , 38 , respectively, in order maintain the least amount of back pressure as possible between supplying and venting the compressed gas to chambers 38 and 40 .
[0057] Referring now to FIGS. 9B and 10A movement of the saw blade in the second cutting direction opposite to arrow 157 is illustrated. During the traverse from the first cutting direction to the second cutting direction reciprocating valve 132 is in the second position (See FIG. 10A ) wherein first check valve 140 is open ( FIG. 11B e.g., no gas provided to inlet 176 ) thereby venting gas from chamber 40 to the atmosphere while second outlet 144 is in fluid communication with inlet 138 allowing fluid communication between the source of compressed gas and chamber 38 via valve 146 in the position illustrated in FIG. 11A thus piston 18 and the saw blade travel in the second cutting direction. It being understood that in order to effect movement towards the second cutting direction the first outlet 136 is closed to conduit 134 and the second outlet 144 is in fluid communication with conduit 142 since the second seal 172 is seated within the second seat 174 thereby opening second outlet 144 thus, causing conduit 142 to be in fluid communication with chamber 38 . Similarly, the first seal 168 is unseated from the first seat 170 thereby sealing first outlet 136 thus, causing conduit 134 to be closed to chamber 40 while chamber 48 is open to atmosphere via first check valve 140 .
[0058] Referring now to FIGS. 9A and 11B , and as the blade moves in the second cutting direction, first check valve 140 is in an un-actuated position configured to release gas from chamber 40 to the atmosphere when compressed gas is not entering through the conduit inlet 176 thereby causing the diaphragm 178 to not close against the valve seat 180 so that compressed gas from chamber 40 via piston passage 182 may vent directly to the atmosphere through an atmosphere outlet 184 instead of venting through the entire length of conduit 134 . This is particularly advantageous because allowing the compressed gas to vent from chamber 40 more quickly allows less back-pressure to retard the movement of the piston 18 . Similarly, referring to FIGS. 9A and 11A , second check valve 146 is in an actuated position configured to supply compressed gas to chamber 38 through the conduit inlet 176 thereby causing diaphragm 178 to close against valve seat 180 so that compressed gas may be supplied to chamber 38 via piston passage 182 .
[0059] In accordance with an alternative embodiment of the present invention, this reciprocal movement of cutting blade 12 , piston 18 , reciprocating valve 132 and assembly 150 will continue until the source of compressed gas released into the inlet conduit 139 in fluid communication with inlet 138 of reciprocating valve ceases.
[0060] Referring now to FIGS. 9A and 9B an alternative embodiment of the present invention is illustrated. Here a frame portion 186 comprises a stop member 188 secured to the end of the frame and extending outward toward the end of the cutting blade 12 . Stop member 188 defines a stop for a limb that is being cut by the pole saw. For example, and as the blade is drawn towards the stop the teeth of the blade will engage the limb and apply a downward force to the limb which in turn may cause the head member to be drawn upward or in an opposite direction to the force being applied to the limb as the blade travels down towards the stop member. Accordingly, and in order to impart the cutting force to the limb in a downward stroke of the blade the stop member provides a surface to receive a portion of the limb on as the blade travels downward towards the stop member.
[0061] While the invention has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. | A pneumatically powered pole saw, comprising: an extendable pole; a head member secured to the extendable pole; a cutting blade movably mounted to the head member; a piston linked to the cutting blade; a reciprocating valve disposed in the head member configured to release compressed gas into the piston chamber on one side of the piston when the reciprocating valve is in a first position causing the cutting blade to move in a first cutting direction, when the cutting blade reaches the limit of travel in the first direction, the reciprocating valve releases compressed gas into the piston chamber on another side of the piston causing the cutting blade to move in a second cutting direction. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national phase application of, and claims priority under 35 USC §119 from, PCT Patent Application PCT/IL2008/001421, filed Oct. 29, 2008, which claims priority U.S. Provisional Patent Application Ser. No. 60/984,399, filed Nov. 1, 2007, which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to disposing pet waste and the like and more particularly to improved apparatus and methods by which pet waste and the like may be disposed without soiling one's hands, while eliminating bad odor and microbial contamination.
BACKGROUND OF THE INVENTION
Due to increasing pet populations, certain large cities have adopted ordinances requiring pet owners to clean up after their pets. Even in areas where such cleanliness is not a prescribed ordinance, it is often desirable to dispose of pet waste and the like in order to maintain attractive lawns and streets which are safe to walk on without soiling one's shoes.
There have been various attempts to deal with these problems in the past. Some individuals have been known to place one of their hands inside a bag of flexible material, such as plastic, as if it were a glove, pick up the waste material using the “gloved” hand, and pull the end of the bag off of the hand in a manner so as to invert the bag around the waste material and package it for later disposal. However, this “gloved” hand method is esthetically unpleasing and otherwise unpleasant to the pet owner, particularly if the bag breaks at an opportune moment.
Other devices utilize a plastic bag and a frame, or multiple frames that may be collapsible and are used as scoops or shovels to place the waste material within the bag so that the bag may be inverted around the excrement and packaged for disposal. However, all these methods suffer from the fact that the waste is biologically active and therefore possess environmental hazards.
A gel composition containing oxidizing agents and thickening or gelling agents has also been proposed to detoxify chemical and biological agents by application directly to a contaminated area. The gelling agent is a colloidal material, such as silica, alumina, or alumino-silicate clays, which forms a viscous gel that does not flow when applied to tilted or contoured surfaces. After decontamination, the residue can be washed away or vacuumed up for disposal.
SUMMARY OF THE INVENTION
The present invention seeks to provide improved apparatus and methods for disposing pet waste by means of combustion, as described more in detail hereinbelow.
Animal droppings (pet waste, feces or exudates, the terms being used interchangeably) are composed of organic matter that in principle may be incinerated or at least sterilized to eliminate bacterial activity and bad odor. However, a major problem associated with fresh feces is their high water content that inhibits incineration and unfortunately provides a good medium for bacterial growth and propagation. Furthermore, the high water content makes the feces sticky and dirty. An attempt to burn fresh feces by an external heat source, such as a gas burner, is typically associated with a formation of external layer of inorganic matter that insulates the wet interior and inhibits heat transfer and combustion thereto. Efficient heat transfer to the interior parts of the feces and water evaporation therefrom are essential components of fecal disposal by heat.
The present invention solves these problems, as described more in detail below, by using a portable waste collection receptacle disposed on a handle, and a heat source mounted together with the waste collection receptacle, capable of incinerating or sterilizing waste disposed in the waste collection receptacle. An oxidizing agent (e.g., potassium permanganate) can be mixed with the waste to generate heat to the waste. This provides efficient heat transfer to the interior parts of the feces and water evaporation therefrom.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawing in which:
FIG. 1 is a simplified pictorial illustration of apparatus for pet waste disposal, constructed and operative in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Reference is now made to FIG. 1 , which illustrates apparatus 10 for pet waste disposal, constructed and operative in accordance with an embodiment of the present invention.
Apparatus 10 may include a waste collection receptacle 12 , which may be a chamber disposed at the end of a handle 13 . Receptacle 12 may be open at an end or side thereof (e.g., open at its bottom surface) or may be closed with a hinged or trap door for allowing entry therein of feces and exit therefrom of ash or other combustion products.
Apparatus 10 includes a heat source 14 capable of incinerating or sterilizing waste 15 . Heat source 14 may include, without limitation, a gas burner, oxidizing agent, laser heater, microwave heater, radiofrequency heater, electric resistance heater and the like, which is capable of drying and burning the organic waste 15 in a relatively short period of time without damaging the environment in general and the operator in particular. Heat transfer elements 16 (e.g., metal rods or plates) may be provided to contact or even pierce the waste 15 to accelerate heat transfer and water evaporation.
In a preferred embodiment, heat is generated by mixing the organic waste 15 with sufficient amount of an oxidizing agent 18 , such as but not limited to, potassium permanganate or any other safe oxidizing agent. Oxidizing agent 18 may be stored in a compartment 20 in apparatus 10 and dispensed via one or more valves 22 . Alternatively, oxidizing agent 18 may be manually dispensed by the operator from an external source (e.g., a bag carried by the operator). A mixing device 23 (such as but not limited to a beater, electrically or manually operated) may be provided for mixing oxidizing agent 18 with the feces.
In another embodiment, the device may contain one or more thermoelectric electrodes 24 that may convert heat to electricity by the Seebeck effect, i.e., the conversion of temperature differences directly into electricity. The electricity produced by the electrodes may be used for electrolysis of the water in the waste to molecular oxygen and molecular hydrogen that may contribute to the incineration of the organic waste. The electricity produced may also be used to charge a battery or operate an electrical device.
Additionally, apparatus 10 may include a collapsible shovel 26 that may be used to pick up the feces and dispose of the byproducts of combustion (mainly ash). Apparatus 10 may be constructed of light materials and have a telescopic body for folding into a small size convenient for carrying. Apparatus 10 may be operated in any open space, such as but not limited to, pavements, lawns, parks etc., without causing any damage.
In an experiment carried out with an embodiment of the invention, 50 gr of dog feces were mixed with about 20 gr of potassium permanganate. After about 20 seconds an exothermic reaction occurred, causing a temperature rise of about 100° C., and converting the feces to a dry odorless material which could be burned easily by a gas burner. The resulting ash was disposed directly on a green lawn. No phytotoxic signs were observed in a period of 30 days, indicating that the disposed material is environmentally safe.
It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art. | Apparatus ( 10 ) for pet waste disposal including a portable waste collection receptacle ( 12 ) disposed on a handle ( 13 ), characterized by a heat source ( 14 ) mounted together with the waste collection receptacle ( 12 ), capable of incinerating waste ( 15 ) disposed in the waste collection receptacle ( 12 ). | 4 |
This is a continuation of application Ser. No. 07/821,344, filed Jan. 13, 1992, now abandoned, which is a continuation of application Ser. No. 07/491,293, filed on Mar. 9, 1990. now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to highly soluble poly(borazylenes), to a direct thermal process, not requiring a catalyst, for preparing poly(borazylenes), and to the use of such poly(borazylenes) as processable precursors for boron nitride. This invention further relates to borazine/polyhedral borane oligomers which can also be made by a direct thermal process without a catalyst.
Interest in the development of ceramic/ceramic composite materials stems from a desire to improve structural integrity over that of a single ceramic component. For example, ceramic fiber reinforced ceramics are known to exhibit increased strength and toughness due to a lessening of crack propagation. Pipes, B. R., McCullough, R. L., Chou, T. W., Scientific American, 1986, 193-203; Bracke, P., Schurmans, H., Vehoest, J., "Inorganic Fibers and Composite Materials" EPO Applied Technology Series Volume 3, Pergamon, New York, 1984. A suitable ceramic fiber coating can enhance the strength of a ceramic fiber/ceramic composite by decreasing the interfacial shear strength between the fiber and matrix and thus increase the potential for fiber pullout (toughness). Another benefit of fiber coatings is that they may serve as a diffusion barrier between fibers and matrix materials and, thus, inhibit chemical reactions between these materials at high temperatures. Boron nitride (BN) is a non-oxide ceramic which because of its excellent strength and chemical resistance is an attractive prospect as a ceramic coating for fibers in ceramic fiber/ceramic composites.
Previous methods for the formation of coatings or thin films of BN have generally relied on the use of vapor deposition (CVD) techniques, employing mixtures of NH 3 and volatile borane species such as BCl 3 , B 2 H 6 and B 3 N 3 H 6 . Gmelin Handbuch der Anorganishen Chemie, Boron Compounds, 1980, Third Supplement, Vol.3, Sec 4 and references therein, and 1988, 3rd Supplement, Volume 3. For example, conventional CVD techniques have been used for the preparation of thin films of BN from a BCl 3 -NH 3 -H 2 mixture at 1000°-1400° C., while plasma assisted CVD of a B 2 H 6 -NH 3 -H 2 mixture results in a deposition of a thin layer of BN in the temperature range of 400°-700° C. Lowden, R. A., Besmann, T. M., Stinton, D. P., Ceram. Bull. 1988, 67, 350-355. Although the CVD technique offers an effective pathway for depositing a uniform layer of a ceramic on a variety of substrates, these procedures are often time consuming and costly. An alternative method for generating BN coatings could employ a coatable, non-volatile chemical precursor which could be thermally decomposed to BN on a desired substrate. Indeed, several boron based polymer systems displaying this set of properties have been developed as potential precursors to BN coatings. Paine, R. T., Narula, C. K., Chem. Rev. 1990, 90, 73-92 and references therein; Narula, C. K., Schaeffer, R., Paine, R. T., J. Am. Cer. Soc. 1987, 109, 5556-5557; Narula, C. K., Paine, R. T., Schaeffer, R., Polymer Prep, (Am. Chem. Soc. Div. Polym. Chem.) 1987, 28, 454; Narula, C. K., Paine, R. T., Schaeffer, R. in Better Ceramics Through Chemistry II, Brinker, C. J., Clark, D. E., Ulrich, D. R. Eds, MRS Symposium Proceedings 73, Materials Research Society:Pittsburgh Pa., 1986, 363-388; Narula, C. K., Paine, R. T., Schaeffer, R., in Inorganic and Organometallic Polymers, Zeldin, M., Wynne, K. J., Allcock, H. S. Eds., ACS Symposium Series 360, American Chemical Society: Washington, D.C. 1988, 378-384; Paciorek, K. J. L., Harris, D. H., Krone-Schmidt, W., Kratzer, R. H., Technical Report No. 4, Ultrasystems Defense and Space Inc., Irvine, Calif. 1978; Paciorek, K. J. L., Krone-Schmidt, W., Harris, D. H., Kratzer, R. H., Wynne, K. J. in Inorganic and Organometallic Polymers, Zeldin, M., Wynne, K. S., Allcock, H. S., Eds., ACS Symposium Series 360, American Chemical Society: Washington, D.C. 1988, 27, 3271; Rees, W. S., Seyferth, D., presented at the 194th National Meeting of the American Chemical Society, New Orleans, La., Sept. 1987, Paper INOR 446; Rees, W. S., Jr., Seyferth, D., J. Am. Ceram. Soc., 1988, 71, C194-C196; Mirabelli, M. G. L., Sneddon, L. G., Inorg. Chem. 1988, 27, 3721; Mirabelli, M. G. L., Lynch, A. T., Sneddon, L. G., Solid State Ionics, 1989, 32/33,655-660; Lynch, A. T., Sneddon, L. G., J. Am. Chem. Soc., 1989, 111, 6201-6209.
Poly(borazylenes), polymers comprising linked borazine rings analogous to organic poly(phenylenes), would be ideal precursors for BN if they could be prepared in high yield and had high enough solubility. Small dehydrodimers and oligomers of alkylated borazine have previously been prepared, primarily either by metathesis or coupling reactions; however, owing to its greater reactivity these procedures are unsuitable for the generation of analogous species based on the parent B 3 N 3 H 6 compound. Wagner, R. I., Bradford, J. L., Inorg. Chem. 1962, 99-106; Brotherton, R. J., McCloskey, A. L., U.S. Pat. No. 3,101,369, 1963, Chem. Abstr. 1964, 60, 547; Gutman, V., Meller, V., Schlegel, R., Monatsh. Chem. 1964, 95, 314-318; Gerrard, W., Hudson, H. R., Mooney, E. F., J. Chem Soc. 1962, 113-119; Harris, J. J., J. Org. Chem. 1961, 26, 2155-2156. The N-B coupled dimer 1:2'- B 3 N 3 H 5 ! 2 has been obtained in low yields from the decomposition of liquid borazine at room temperature over several months (Manatov, G., Margrave, J. L., J. Inorg. Nucl. Chem. 1961, 20, 348-351) and from the gas phase photolytic (Neiss, M. A., Porter, R. F., J. Am. Chem. Soc. 1972, 94, 1438-1443) or pyrolytic (Laubengayer, A. W., Moews, P. C., Jr., Porter, R. F., J. Am. Chem. Soc. 1961, 83, 1337-1342) reactions of borazine. The latter two studies also reported the formation of insoluble solids that were proposed to have fused borazine polycyclic structures. Several studies of the stability of liquid borazine have also reported the formation of white low volatile solids, but these materials were not identified. Manatov, G., et al., Op cit.. Schaeffer, R., Steindler, M., Hohnstedt, L., Smith, H. R., Jr., Eddy, L. B., Schlesinger, H. I., J. Am. Chem. Soc. 1954, 76, 3303-3306; Haworth, D. T., Hohnstedt, L. F., J. Am. Chem. Soc. 1960, 82, 3860-3862.
The preparation of certain polyborazine BN-precursors, in which borazine rings are linked by a bridging nitrogen atom, are disclosed in U.S. Pat. No. 4,801,439 (Blum et al.). Blum et al. disclose that compounds containing at least one Group IIIA metal-Group VA nonmetal bond can be prepared by reacting a first reactant having at least one ZH bond where Z represents a Group. VA nonmetal with a second reactant that has at least one M-H bond where M is a Group IIIA metal in the presence of a metal catalyst. The metal catalysts disclosed by Blum et al. for use in their method include: homogeneous catalysts such as H 4 Ru 4 (CO) 12 , Ru 3 (CO) 12 , Fe 3 (CO) 12 , Rh 6 (CO) 16 , Co 2 (CO) 8 , (Ph 3 P) 2 Rh(CO)H, H 2 PtCl 6 , nickel cyclooctadiene, Os 3 (CO) 12 , Ir 4 (CO) 12 , PdCl 2 , (PhCN) 2 PdCl 2 , (Ph 3 P) 2 Ir(CO)H, Pd(OAc) 2 , CP 2 TiCl 2 , (Ph 3 P) 3 RhCl, H 2 Os 3 (CO) 10 , Pd(Ph 3 P) 4 , Fe.sub. 3 (CO) 12 /Ru 3 (CO) 12 complexes of metal hydrides, and heterogeneous catalysts such as alkaline metals (e.g., Na, K), Pt/C, Pt/BaSO 4 , Cr, Pd/C, Co/C, Pt black, Co black, Pd black, Ir/Al 2 O 3 , Pt/SiO 2 , Rh/TiO 2 , Rh/La 2 O 3 , Pd/Ag alloy, LaNi 5 , PtO 2 , tranasition metal salts, transition metal hydrides or other transition metal oxides. It is disclosed that either the first reactant or the second reactant, or both, may be borazine. Comparative examples presented in the patent show that preparations carried out in the absence of metal catalyst either did not produce the desired product or produced no product at all. No examples are given of the preparation of a poly(borazylene) polymer.
In Lynch, A. T., Sneddon, L. G., Abstracts of Papers of American Chemical Society Meeting, Los Angeles, Calif., 1988, paper No. 296, the polymerization of borazine in the presence of CpTiMe 2 catalyst was reported. The resulting poly(borazylene), after recrystallization, cannot be totally redissolved in organic solvents such as THF or glyme. Further, upon standing for extended periods of time, e.g., at least about one week, the poly(borazylene) prepared using metal catalyst becomes totally insoluble in solvents such as ethers and glyme. Since a processable (i.e., soluble) poly(borazylene) is desired for use as a BN ceramic precursor, the material prepared according to the Lynch et al. disclosure has obvious disadvantages.
Transition metal promoted reactions producing coupled products of borazine and polyhedral boranes have been disclosed. A. T. Lynch, Ph.D. Thesis, University of Pennsylvania, 1989. However, there have been no reports of a simple thermolytic route to these species.
Swiss Patent 670 105, published Dec. 5, 1989, discloses a photolytic method for making dimers of borazine which can be used to make BN coatings. These dimeric mixtures are composed of diborazine and borazanaphthalene or mixtures of the two. The patent suggests that reaction times can be shortened by using transition metal catalysts.
SUMMARY OF THE INVENTION
It has now surprisingly been found that highly soluble poly(borazylenes) may be prepared by a thermal polymerization process in the absence of any catalyst. The polymerization of the compounds in the absence of catalyst is surprising as the common view, as expressed in the Blum patent, U.S. Pat. No. 4,801,439, was that metal catalysts were necessary for any polymerization reaction to borazine to occur. In addition, oligomers of borazine with polyhedral boranes, carboranes or heteroboranes can also surprisingly be prepared by a thermal process in the absence of catalyst.
The poly(borazylenes) prepared according to this method appear to have chain-branched structures and therefore have distinct advantages over those prepared in the presence of metal catalyst in that they exhibit greater solubility in organic solvents. Tests indicate that the poly(borazylenes) prepared in the absence of metal catalyst, and thus containing no measureable traces of such catalyst, are, after recrystallization (e.g., in organic solvents such as THF or glyme), completely soluble in organic solvents and retain their solubility for extended periods of time.
This invention therefore relates to a novel method for preparing poly(borazylenes) or oligomers of boraznes with polyhedral boranes, carboranes or heteroboranes comprising heating one or more borazines or a mixture of borazine and polyhedral boranes, carboranes, or heteroboranes in the absence of any catalyst. This invention further relates to the compositions so prepared, namely, to the poly(borazylenes) which have molecular weights of at least about 500 or the borazine/polyhedral borane, carborane or heteroborane oligomers which are free of measureable traces of metal catalyst and which are useful as ceramic precursors. Still further, this invention relates to articles such as ceramic films, fibers, bodies and ceramic coated substrates which are made using the such ceramic precursors.
DETAILED DESCRIPTION OF THE INVENTION
The term "borazines" as used to define the starting materials utilized to prepare the poly(borazylenes) of this invention includes the compound borazine as well as any optionally mono-, di- or tri-B- alkylated borazine. The borazines useful in this invention have at least one B-H or N-H bond. Although the preferred starting material is unsubstituted borazine, excellent results have also been obtained utilizing B-ethylborazine. The polyhedral boranes, carboranes or heteroboranes useful in this invention are well known in the art, all have at least one B-H bond, and include such compounds as pentaborane(9), decaborane(14), C 2 B 10 H 12 , C 2 B 8 H 10 , SB 9 H 11 and S 2 B 7 H 9 .
Since the poly(borazylenes) and the oligomers are prepared in the absence of catalyst, they are free of measureable traces of catalysts, especially of the metal catalysts heretofore thought necessary for such reactions. Metal catalysts used in prior art processes, which are absent from the products of this invention, are, for example, as described in U.S. Pat. No. 4,801,439 to Blum et al. Generally, these catalysts are those in which a transition metal having eight d electrons is present, such as Rh, Pd and Ir. Other metal catalysts are based on Ti such as the catalysts described by Lynch et al., Abstracts of Papers, supra.
The poly(borazylenes) of this invention are conveniently prepared by heating the appropriate borazine starting material to a polymerizing temperature in the absence of any catalyst. The appropriate temperature will depend upon the starting compound but will generally be at least about 65° C. Higher temperatures, and longer reaction times, are needed for alkylated borazines. For example, a temperature of about 110° C. is preferred for polymerizing B-ethylborazine. The heating step is preferably performed in vacuo, although it could also be performed under an inert gas. Since the starting materials are liquids, no solvents are required, but any nonreactive organic solvent could be used if desired.
To prepare B-alkylated borazine starting borazine and an appropriate olefin may be contacted in the presence of a catalytic amount of a transition metal catalyst. Approximately stoichiometric quantities of the borazine and the olefin are generally used, although a slight excess of either reactant may be preferred. The transition metal catalysts useful in preparing the B-alkylated borazines are compounds well known in the art. The preferred catalysts are those in which the transition metal is one having eight d electrons, and the more preferred catalysts are those in which the transition metal is selected from Rh, Pd and Ir. Examples of transition metal catalysts are those which contain dissociable basic ligands, such as carbon monoxide or phosphines, e.g., RhH(CO)(PPh 3 ) 3 , Ir(CO)Cl P(C 6 H 5 ) 3 ! 2 , and (Me 2 C 2 )Co 2 (CO) 6 . Another class of transition metal catalysts which should be useful are those developed by P. M. Matilis, Accts. of Chem. Res. 11, 301-307 (1978), the disclosure of which is hereby incorporated by reference. These catalysts do not contain basic ligands but are based on pentamethylcyclopentadienyl-rhodium and -iridium.
The poly(borazylenes) of this invention have molecular weights of at least about 500 and are highly soluble. The term "highly soluble" as used in this application is intended to encompass those compounds which are soluble (i.e., greater than 1.0 wt. %, but generally at least about 50 wt. %) in common polar solvents such as tetrahydrofuran and glyme. Although not intending to be bound by such theory, it is believed that the poly(borazylenes) prepared according to this invention are more highly chain-branched than those prepared via catalytic methods and that their high solubility is a result of such chain-branching. The advantages of a soluble ceramic precursor are clear. By virtue of the processability of the precursor, the final ceramic material may be used in a variety of applications, such as thin films, fibers and coatings, not practically available using non-processable precursors.
The poly(borazylenes) prepared according to this invention appear to have a complex structure, having linear and branched chain segments, related to those of the organic poly(phenylenes), in which the borazine rings are joined primarily by B-N linkages. The polymer is isolated as a white powder that is highly soluble in polar solvents, and that according to SEC/LALLS analysis has M w ranging from 2,100 g/mol to 7,600 g/mol and M n between 980 g/mol and 3,400 g/mol.
The poly(borazylenes) can be pyrolyzed to BN in high ceramic (generally at least 85-93%) and chemical (89-98%) yields by methods known in the art. Generally, the precursors are slowly heated (5°-10° C. per minute) to a temperature in the range of about 500° to 1200° C. under either argon or ammonia. Thermogravimetric analysis of the ceramic conversion shows that the polymer follows a well defined decomposition path in which an initial (2%) weight loss (probably resulting from polymer crosslinking) occurs in a narrow range between 125` to 300° C., followed by a gradual 4% loss ending by 1100° C. Thus, poly(borazylene) appears to be an excellent precursor to boron nitride which, because of its solubility, low temperature decomposition and high ceramic and chemical yields, make it excellent candidate for the generation of, for example, fibers and coatings of boron nitride.
The borazine/borane, carborane or heteroborane oligomers may also be prepared in high yields by heating mixtures of the liquid reactants, neat or in an appropriate nonreactive solvent, in the absence of catalyst. For example, pentaborane (9)/borazine oligomers have been formed by heating the reactants at temperatures between 45°-100° C. in vacuo for periods ranging from 2 to 24 hours. These oligomers are useful as precursors for boron enriched ceramics, the ceramics being prepared by pyrolysis under conditions analogous to those discussed above.
Myriad uses exist for the ceramic materials which can be made as described above. They may be used, for example, to prepare refractory bodies, fibers and composites. By virtue of the processability of the ceramic precursors of this invention, the ceramic materials prepared therefrom may be utilized in other applications. For example, thin BN films may be made by casting thin films of the precursor and then pyrolyzing the film. BN fibers may be made by drawing fibers from a solution of the precursor and pyrolyzing. In a similar manner, substrates such as but not limited to fibers and silicon chips may be coated with BN by coating the substrate with the soluble precursor and then subjecting the coated substrate to pyrolysis conditions. The soluble precursor may also be injection molded into any shape desired. Green bodies which will retain their shape are formed by heating to a temperature of about 200° to 400° C. for at least two hours. In each of these applications, the availability of a soluble ceramic precursor allows for preparation of the ceramic article under milder conditions than those required by conventional powder methods which must be used with less processible precursors.
The methods and products of this invention are further illustrated in the following examples which are not intended to limit the scope of the invention.
EXAMPLE 1
Formation of Poly(Borazylene)
Borazine (3.15 g, 39.1 mmol) was condensed into an evacuated flask at -196° C. and warmed to 70° C. After 48 h the solution became viscous and the reaction was stopped. The flask was degassed and the volatiles including all diborazine or borazanaphthalene were removed under vacuum. The solid residue (2.84 g, 90% yield) was dissolved in dry tetrahydrofuran (THF) and recrystallized using dry pentane to precipitate the polymer. The recrystallized polymer was dried under vacuum giving a fine white powder (1.93 g, 61% yield). The polymer was characterized by 11 B NMR, elemental analysis, uv, diffuse reflectance infrared, and size exclusion chromatography/low angle laser light scattering.
11 B NMR (160.5 MHz, THF) 31 ppm (s,vbr). Elemental Analysis: calcd. for (B 3 N 3 H 4 ) x : B, 41.32; N, 53.54; H, 5.14 fd: B, 42.33; N, 53.25; C, 1.09; H, 3.49. UV absorbance at λ max 220 nm. IR (diffuse, KBr) 3445 m, 3230 m,br, 2505 m, 1450 s,br, 1200 m, 900 m, 750 m, 690 m; Mw=7600±460; Mn=3400±210; Mw/Mn=2.23.
Molecular weight studies using size exclusion chromatography/low angle laser light scattering (SEC/LALLS) indicate that the crude material, before recrystallization (M w =4000±540, M n =1400±190, M w /M n =2.86) and the recrystallized sample (M w =7600±460, M n =3400±210, M w /M n =2.23) show broad molecular weight distributions. Thus, based on a linear chain model, D n (number average degree of polymerization) for these materials ranges from 18 to 43 and D w (weight average degree of polymerization) from 51 to 97. Polymerizations carried out for shorter times, for example 24 hours, showed correspondingly lower molecular weight averages (M w =2100±330, M n =980±150).
Evidence of chain branching was also found in the LALLS chromatograms of both the crude and recrystallized polymers, where early eluting high molecular weight components characteristic of highly branched or partially crosslinked chains were observed. In addition, the SEC/LALLS/UV studies showed that polymers in the high molecular weight end of the molecular weight distribution, including the high molecular weight component detected by the LALLS detector, had greater UV absorbance per unit mass than those in the lower molecular weight region of the molecular weight distribution. This heterogeneity with respect to UV absorbance at the high molecular weight end of the molecular weight distribution is consistent with the greater availability of branching sites.
Although its detailed structure has not been established, the polymer is proposed to be composed primarily of linked borazine rings, analogous to those of the organic poly(phenylene) polymers. Since small amounts of the N:B coupled dimer 1:2'-(B 3 N 3 H 5 ) 2 are isolated in the volatile materials from the reaction, the polymer is likely to contain N-B linkages between the borazines. Consistent with this interpretation, the 11 B NMR spectrum has a broad peak centered in the borazine region at 31 ppm. Also isolated in the volatiles were small amounts of borazanaphthalene, thus it is possible that the polymer also contains some degree of fused ring structure.
EXAMPLE 2
Fiber Coatings with Polyborazylene
Fiber bundles were dipped in dilute solutions (0.1-5.0%) of polyborazylene in tetrahydrofuran. Excess solution was removed by agitating the bundle until the coating appeared uniform. The coated bundles were placed in a ceramic boat lined with platinum foil which was transferred to a tube furnace. The fiber bundles were then pyrolyzed under argon to 1000° C. After pyrolysis the resulting BN coatings were characterized by Scanning Electron Microscopy and Auger Electron Spectroscopy.
EXAMPLE 3
Polyborazylene Fibers
A 30% w/w solution of polyborazylene in tetrahydrofuran (THF) was made viscous by vacuum evaporating solvent until the solution was unable to be stirred by a magnetic stirring bar. A drop of the solution was then placed between two spatulas and pulled apart to form a fiber. Once the solvent evaporated the fiber was placed in a ceramic boat lined with platinum foil and transferred to a tube furnace where it was pyrolyzed under argon to 1000° C. Analysis of the resulting fiber by scanning electron microscopy and Auger spectroscopy revealed the formation of a 50 μm boron nitride fiber.
EXAMPLE 4
Formation of Poly(B-Ethyl Borazylene)
B-Ethylborazine (1.25 g, 11.5 mmol) was condensed into an evacuated flask at -196° C. The reaction flask was heated at 110° C. for eight days. The flask was degassed and volatile components removed under vacuum. The solid residue was dissolved in dry tetrahydrofuran (THF), filtered (through a fine frit), and recrystallized using dry pentane to precipitate the polymer from solution. The polymer was then dried under vacuum giving a fine white powder 0.304 g, 24%. The polymer was characterized by 11 B NMR, diffuse reflectance infrared spectroscopy, and elemental analysis. 11 B NMR (115.5 MHz, THF) 36 ppm (s,vbr). BR (diffuse KBr) 3445 m, 2952 m, 2873 m, 2508 m,br, 1489 s,br, 896 m, 766 m, 693 m. Elemental Analysis: calcd for (B 3 N 3 H 3 C 2 H 5 ) x : B, 30.44; N, 39.47; H, 7.56; C, 22.53; fd: B, 32.37; N, 43.45; H, 6.05; C, 16.81.
EXAMPLE 5
B-Ethylborazine Preparation
In a typical reaction, 10 mg (1.09×10 -2 mmol) of RhH(CO)(PPh 3 ) 3 were placed in a Fisher-Porter pressure vessel which was then evacuated. Borazine (2.77 g, 34.4 mmol) and ethylene (9.0 mmol) were condensed into the flask at -196° C., and the mixture was warmed to room temperature. A two to three fold excess of borazine was used to minimize the formation of di-and triethylborazine. The reaction was allowed to stir for 12 h and then vacuum fractionated through a 0°, -20°, -45°, and -196° C. trap series. The -20° and -45° C. fractions were refractionated to separate B-ethylborazine from unreacted borazine with pure B-ethylborazine remaining in the -20° C. trap. The compound was characterized by 11 B and 1 H NMR and IR. 11 B NMR (160.5 MHz, C 6 D 6 ) 31.5 ppm (d, J BH =135 HZ, B4B6) , 36.7 (S, B2), 1 H NMR (500 MHZ C 6 D 6 ) 0.64 (q, J CH .sbsb.3 CH .sbsb.2 =8 Hz, CH 3 ) , 0.80(t, J CH .sbsb.2 CH .sbsb.3 =7.8 Hz, (CH 2 , 2), 4.57 (q, br, J BH =131 Hz, BH, 2), 4.82 (t, J NH =50 HZ, NH, 2), 4.99 (t, J NH =40 Hz, NH, 1). IR (Gas cell, NaCl windows, 10 cm) 3478 m, 2970 m, 2920 n, 2895 m, 2590 w, 2510 s, 2420 w, 1475 vs,br, 1440 vs, 1390 s, 1355 w, 1110 w, 930 m, 915 s, 770 w, 720 m.
EXAMPLE 6
Borazine/Pentaborane (9) Preparation
In a typical reaction 1.78 g (28 mmol) of pentaborane(9) and 1.21 g (15 mmol) of borazine were condensed at -196° C, into an evacuated, 50 mL one neck flask equipped with a magnetic stirring bar. The flask was warmed at 65° C. and the solution stirred for 24 h. At the end of this period the flask was degassed and the volatile contents (100-200 mg) vacuum fractionated through a -45° and -196° C. trap series. Stopping in the -45 ° C. trap were borazanaphthalene, diborazine, borazine-pentaborane coupled products, and pentaborane dimers. Remaining in the reaction flask was 50-100 mg of an opaque greenish-yellow material composed of pentaborane/borazine oligomers.
Analysis of the volatile materials by GC/mass spectroscopy showed: (Retention time, m/e) borazanaphthalane 5.18 rain, 133 m/e; pentaborane dimers (B 5 H 8 ) 2 , isomer I, 6.14 min, 124 m/e; isomer II, 6.3 min., 124 m/e; borazinepentaborane B 3 N 3 H 5 -B 5 H 8 , isomer I, 6.52 min., 123 m/e; isomer II, 6.82 min., 143 m/e and diborazine 7.08 min, 160 m/e. The identity of each of these products was then confirmed by comparison of their NMR data with those reported previously. | Direct thermal syntheses in the absence of catalyst, of poly(borazylenes) and of oligomers of borazine with polyhedral boranes, carboranes or heteroboranes are disclosed. The products of these syntheses are precursors to BN or other boron-containing ceramics. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This technology relates to oil and gas wells, and in particular to adaptors for clamping connectors in oilfield equipment.
[0003] 2. Brief Description of Related Art
[0004] Conventional adapters for joining tubular wellhead components, such as API hub connectors, have two-piece clamps that are positioned to engage the flanges of the components, and are joined with bolts. The wellhead components may be, for example, a casing or wellhead, and a tubing head. Such adapters are often slow and cumbersome to install. In addition, such adapters may be unreliable, thereby allowing leakage between the flanges, and raising environmental and safety concerns. Alternative adapters have been developed to overcome the shortcomings of conventional two-piece clamps. For example, some adapters may drive dogs around the flanges to clamp the flanges together. However, many of these adapters require vendor-specific non-standard threads or other features on the components or equipment to which they are applied. This prohibits the use of such adapters with any equipment that is not specifically designed for use with that adapter. This also prevents use of the adapter to retrofit equipment originally supplied by a vendor other than the vendor of the adapter. What is needed, therefore, is an adapter that is more reliable than the conventional two-piece clamp adapter, but that can be used universally with any oil field equipment manufactured by any vendor.
SUMMARY OF THE INVENTION
[0005] Disclosed herein is an adapter for clamping flanged, or hub, ends of first and second tubular components. The adapter includes a clamp that may have two split halves, or a plurality of dog segments, with each half or dog segment having a hole extending therethrough. Each half or dog segment also includes upper and lower protrusions that define a recess therebetween, and that are spaced to accept the flanges at the ends of the first and second tubular components.
[0006] The adapter also includes a housing that surrounds at least an outer portion of the clamp. The housing is configured for removable attachment to either the first or second tubular component, or both. Such attachment may be accomplished by means of fasteners attaching the housing to the tubular component(s), or threads on the surface of the housing configured to engage threads on the surface of the tubular component(s).
[0007] A plurality of drive screws pass through the housing and engage threads in the holes of the clamp. As each drive screw rotates, it drives a half or dog segment of the clamp perpendicularly relative to the first and second tubular components. When the screw drives the clamp into engagement with the flanges, the clamp is in a locked position. Alternatively, when the screw drives the clamp away from, and out of engagement with, the flanges, the clamp is in an unlocked position.
[0008] This adapter is stronger and more robust than conventional split-type, two-piece clamps that consist only of the clamp to hold the faces of the connectors together. The adapter disclosed herein includes both an inner clamping device, and an outer housing that adds strength to the adapter assembly. This increases the ability of the adapter to withstand increased pressure and bending forces compared to conventional clamp designs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present technology will be better understood on reading the following detailed description of nonlimiting embodiments thereof, and on examining the accompanying drawings, in which:
[0010] FIG. 1A is a side cross-sectional view of a connection assembly according to an embodiment of the present technology, with the clamp in an unlocked position;
[0011] FIG. 1B is a side cross-sectional view of the connection assembly according to the embodiment of FIG. 1A , with the clamp in a locked position;
[0012] FIG. 2A is a side cross-sectional view of a connection assembly according to an alternate embodiment of the present technology, with the clamp in an unlocked position; and
[0013] FIG. 2B is a side cross-sectional view of the connection assembly according to the embodiment of FIG. 2A , with the clamp in a locked position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] The foregoing aspects, features, and advantages of the present technology will be further appreciated when considered with reference to the following description of preferred embodiments and accompanying drawings, wherein like reference numerals represent like elements. In describing the preferred embodiments of the technology illustrated in the appended drawings, specific terminology will be used for the sake of clarity. However, the technology is not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose.
[0015] Many oilfield operations require the connection of adjacent tubular components, such as API hub connectors. Such tubular components may typically include wellhead components, like casing heads or tubing heads. For example, as shown in FIG. 1A , such equipment may include a first tubular component 10 having a first flange 12 at a lower end. The first tubular component 10 may be attached to a corresponding second tubular component 14 , which has a second flange 16 . Typically, when the first and second tubular components 10 , 14 are joined, a seal 18 is positioned therebetween to prevent fluids from leaking through the joint at the interface between the flanges 12 , 16 . As shown, for example, in FIG. 1A , an adapter assembly 20 according to the present technology may be used to lock the first and second flanges 12 , 16 together. Such an adapter assembly 20 connects the first and second tubular components 10 , 14 , and keeps them from separating. The adapter assembly described herein is compact, and fits within the minimum clearance outlined by the API 16A standard, as promulgated by the American Petroleum Institute. Accordingly, the adapter assembly 20 may be used with any API 6A hub connection, including those supplied by any vendor.
[0016] The adapter assembly includes a clamp 22 having a recess 24 . The clamp 22 may be divided into separate halves, or multiple dog segments, around the circumference of the first and second tubular components 10 , 14 . The clamp 22 is configured to move between an unlocked position, shown in FIG. 1A , and a locked position, shown in FIG. 1B , and as described in detail below. When the clamp 22 is in the locked position, as shown in FIG. 1B , the recess 24 accepts the first and second flanges 12 , 16 . The recess 24 is bounded on the top and the bottom by an upper protrusion 26 and a lower protrusion 28 respectively, and is configured to accept the first and second flanges 12 , 16 when the flanges 12 , 16 are joined together. In addition, each section, or dog segment, of the clamp 22 includes a hole 38 that may be threaded.
[0017] The upper and lower protrusions 26 , 28 of the clamp 22 may optionally have tapered surfaces 30 , 32 configured to substantially correspond to matching tapered surfaces 34 , 36 of the first and second flanges 12 , 16 . This allows a more even distribution of forces on the clamp 22 by the flanges 12 , 16 when the clamp is in the locked position. In addition, the tapered surfaces may allow easier entry of the flanges 12 , 16 into the recess 24 as the clamp 22 moves into a locked position, even when the flanges 12 , 16 are not perfectly aligned with the clamp 22 . Furthermore, as the tapered surfaces 30 , 32 of the upper and lower protrusions 26 , 28 engage the tapered surfaces 34 , 36 of the first and second flanges 12 , 16 , the protrusions 26 , 28 will tend to squeeze the flanges 12 , 16 together, thereby strengthening the seal between the flanges.
[0018] In FIGS. 1A and 1B , a housing 40 is shown attached to the first tubular component 10 , and substantially surrounding at least the outside, upper, and lower portions of the clamp 22 . Although not shown, the housing 40 may alternatively be attached to the second tubular component 14 , or to both the first and second tubular components 10 , 14 simultaneously. The housing 40 may be a single annular piece that surrounds the clamp 22 . Internal corners 60 of the housing 40 may be radiused, as shown, thereby decreasing stress concentrations in the housing 40 . The housing 40 provides additional structural support to the adapter assembly 20 compared with a conventional clamp assembly that does not include such a housing 40 .
[0019] In the embodiment shown in FIGS. 1A and 1B , the housing 40 is attached to the first tubular component 10 by fasteners 44 and a bracket 62 . The bracket 62 is an L-shaped member having an upright portion bolted to the first tubular member 10 by a bolt. Fastener 44 extends axially downward through a hole in the horizontal part of the bracket 62 into a threaded hole in the housing 40 . The bracket 62 may be an annular member that surrounds the first tubular component 10 . Alternatively, there may be multiple brackets 62 attached to the housing 40 and the first tubular component 10 at discrete intervals around the first tubular component 10 . The inner diameter of the housing 40 may be less than the inner diameter of the bracket 62 . Such an arrangement allows the housing 40 to be easily retrofit onto any existing tubular component, regardless of vendor, by hole forming a threaded hole in the tubular component to accept the fastener 44 . Accordingly, the adapter assembly 20 may be used with existing equipment at an oil drilling site.
[0020] The housing 40 provides a channel 42 in which the clamp 22 runs. The channel is defined by downward and upward facing flat surfaces that are perpendicular to the longitudinal axis of the first and second tubular components. When in its unlocked position, as shown in FIG. 1A , the clamp 22 is retracted into the channel 42 , with an outside surface 46 of the clamp 22 proximate to the housing 40 . Conversely, when in its locked position, as shown in FIG. 1B , the clamp 22 is extended at least partially out of the channel 42 . Optional wear pads 48 may be positioned on the upper and lower flat surfaces of the channel 42 between the housing 40 and the clamp 22 to protect the surfaces of the housing 40 and the clamp 22 as the clamp 22 moves relative to the housing 40 . The wear pads 48 protect surfaces from wear by being constructed of a high strength material that is less susceptible to deterioration over time. The wear pads 48 act to reduce the friction between moving parts, and prolong the life and usage of the parts. In addition, the wear pads 48 are replaceable, adding further flexibility to the design. The channel 42 may be dimensioned so that the clamp 22 fits therein with limited tolerance, thereby helping to ensure that the clamp sections or dog segments remain square to the ends of the first and second flanges 12 , 16 .
[0021] Movement of the clamp 22 between its unlocked and locked positions is effected by drive screws 50 . There may be a drive screw 50 corresponding to each clamp section or dog segment. Each drive screw 50 is configured to pass through a hole in the outer sidewall of the housing 40 and into a hole 38 in the clamp 22 . Threads 52 on each drive screw 50 interact with corresponding threads on each hole 38 of the clamp 22 , so that when the drive screw 50 rotates, the threads 52 drive the clamp 22 toward or away from the first and second flanges 12 , 16 of the first and second tubular components 10 , 14 . As the threads 52 on the drive screw 50 drive the clamp 22 , the drive screw 50 maintains substantially the same position relative to the housing 40 , and does not travel inwardly or outwardly toward or away from the flanges 12 , 16 . In other words, the drive screw 50 may be fixed relative to the housing 40 in an axial direction. The drive screws 50 have a tool engagement slot 54 at an outer end thereof that can be used to turn the drive screw 50 . For example, in the embodiments of FIGS. 1A and 1B , the drive screw 50 has a hexagon head that can be turned with a high impact gun using a hexagon attachment. The drive screws 50 may be made of a high strength material.
[0022] A guide bushing 56 may be provided in hole in the sidewall of the housing 40 to provide a path for, and help align, each drive screw 50 relative to the housing 40 . The guide bushings 56 may be made of a high strength material, and may be bored to have a diameter with a close tolerance to the diameter of the drive screw 50 to guide the drive screw 50 through the housing 40 . The guide bushing 56 may be removable to allow greater access to the drive screws 50 and the clamp 22 .
[0023] Referring now to FIGS. 2A and 2B , there is shown an embodiment of the present technology that is similar to that shown in FIGS. 1A and 1B , and discussed above. For example, the embodiment of FIGS. 2A and 2B includes a first tubular component 110 having a first flange 112 , a second tubular component 114 having a second flange 116 , and a seal 118 therebetween. Furthermore, the adapter assembly 120 includes a clamp 122 , a housing 140 , and drive screws 150 configured to drive the clamp 122 relative to the housing 140 . The clamp 122 includes a recess 124 , protrusions 126 , 128 having angled surfaces 130 , 132 , and a threaded hole 138 . The housing 140 includes a channel 142 in which the clamp 122 slides. Wear pads 148 may be inserted to maintain a separation between surfaces of the housing 140 and surfaces of the clamp 122 , and to prevent wear to the surfaces of the housing 140 and the clamp 122 , thereby prolonging the life thereof. The drive screws 150 include threads 152 and are turned by inserting a tool into a tool engagement slot 154 and turning the drive screw 150 . Bushings 156 are provided in the housing 140 to align the drive screws 150 with the housing 140 . Each of the elements herein identified functions in a similar way to similar elements shown in FIGS. 1A and 1B and described above.
[0024] One feature of the embodiment shown in FIGS. 2A and 2B that is not described above, however, is the threads 158 , which allow the housing 140 to be threadedly attached to the first tubular component 110 , rather than being attached using fasteners, as shown in the embodiment of FIGS. 1A and 1B . The threads 158 extend circumferentially around the first tubular component 110 , and an inner diameter of the housing 140 . The ability to threadedly engage the housing 140 and the first tubular component 110 may be advantageous because it may provide a more secure connection and additional stability to the adapter assembly 120 relative to the first tubular component 110 . Of course, although the housing 140 is shown in FIGS. 2A and 2B to be attached to the first tubular component 110 , it may alternatively be attached to the second tubular component 114 , or to both the first and second tubular components 110 , 114 simultaneously.
[0025] Also shown in FIGS. 2A and 2B is a retainer plate 164 and bolt 166 . The retainer plate 164 is positioned on top of the housing 140 , and the bolt 166 attaches the retainer plate 164 to the housing 140 . The inner surface 168 of the retainer plate 164 has a diameter that is less than the diameter of the threads 158 , so that the retainer plate 164 cannot slide past the threads 158 . Accordingly, the retainer plate 164 , when mounted to the top of the housing 140 , prevents the housing 140 from moving axially downward relative to the first tubular component 110 past the threads 158 . Thus, the adapter assembly 120 cannot unthread and become detached from the first tubular member 110 .
[0026] The method for locking first and second tubular components 10 , 14 together using the adapter assembly 20 of the present technology includes first aligning the flanges 12 , 16 of the first and second tubular components 10 , 14 . In addition, the adapter assembly 20 is installed on the upper tubular member 10 . The adapter assembly 20 may be pre-assembled prior to installation on the first or second tubular components 10 , 14 . For example, the clamp 22 may be pre-attached to the housing 40 by passing the drive screws through the housing 40 and into threaded engagement with the holes 38 in the clamp sections, or dog segments. It may be desirable to turn the drive screws 50 so that the clamp 22 is fully retracted into the channel 42 of the housing 40 during installation. With the adapter assembly 20 assembled, the housing 40 may be attached to either the first or second tubular components 10 , 14 , or both, using the fasteners 44 . Alternatively, the housing 40 may be threadedly engaged with at least one of the tubular components, as shown in FIGS. 2A and 2B .
[0027] Once the adapter assembly 20 is in place relative to the first and second tubular components 10 , 14 , with the housing attached thereto, the drive screws 50 can be turned, by engaging a tool with the tool engagement slots 54 at the end of each drive screw 50 . As the drive screws 50 turn, the threads 52 of the drive screws engage with the threaded holes 38 of the clamp sections, and the clamp 22 is driven inward toward the flanges 12 , 16 of the first and second tubular components 10 , 14 . The clamp 22 may be driven inward until the recess 24 accepts the flanges 12 , 16 . In some embodiments, the tapered surfaces 30 , 32 of the upper and lower protrusions 26 , 28 may engage the tapered surfaces 34 , 36 of the first and second flanges 12 , 16 . As the tapered surfaces 30 , 32 of the upper and lower protrusions 26 , 28 engage the tapered surfaces 34 , 36 of the first and second flanges 12 , 16 , the first and second flanges 12 , 16 are squeezed together and the seal between the flanges is strengthened. With the clamp thus positioned, the first and second flanges 12 , 16 are locked, and unable to separate.
[0028] While the technology has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention. Furthermore, it is to be understood that the above disclosed embodiments are merely illustrative of the principles and applications of the present invention. Accordingly, numerous modifications may be made to the illustrative embodiments and other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. | An assembly for clamping flanged tubular components, the assembly including a segmented clamp having a recess configured to accept the flanges of the tubular components, and a hole oriented substantially perpendicular to the longitudinal axes of the tubular components. The assembly also includes a housing surrounding an outer portion of the segmented clamp and configured for attachment to at least one of the tubular components, and a drive screw that passes through the housing and is threadedly engaged with the hole of the segmented clamp. As the drive screw rotates, it drives the segmented clamp perpendicularly relative to the tubular components between a locked position, in which the circumferential recess engages the flanges of the tubular components, and an unlocked position, in which the circumferential recess is positioned laterally out of engagement with the flanges of the tubular components. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a divisional of, and claims priority to, U.S. patent application Ser. No. 11/623,391, filed Jan. 16, 2007, the entire contents of which are hereby incorporated by reference; this patent application claims priority to and thus the benefit of an earlier filing date from U.S. Provisional Patent Application No. 60/758,778, filed Jan. 13, 2006, the entire contents of which are hereby incorporated by reference.
BACKGROUND
[0002] Snaps are fastening mechanisms that may be used to secure one member to another. For example, snaps are commonly used to secure plastic components together in consumer goods such as electronic devices or toys. Snaps are often integrated into the components to be secured to each other, thus reducing or eliminating the need for separate connection members such as screws. Snaps typically include a flexible portion that may deflect during assembly. They may further include a protrusion that may interconnect or interact with a mating portion to secure the components together.
[0003] A snap may be intended for one-time operation or it may be intended for multiple assembly and disassembly cycles. The difference is often in the design of the protrusion. In a multiple cycle design, a portion of the protrusion may be angled so that a separation force acting on the parts causes the snap to disengage. Often, the snaps may begin to fail, or change in their ability to secure the components to each other, after a small number of assembly and disassembly cycles.
[0004] A one-time snap may have a protrusion that includes an engagement surface that is oriented perpendicular to a separation force acting on the parts. The engagement surface may interlock with a mating component. In this regard, such a force may not cause the part to disengage and the parts may be secured together until the separation force causes a component to fail.
[0005] Known snaps are often configured to require a tool to disengage the snap and allow the components to be separated. Frequently, the proper way to disengage the snap and separate the components is not obvious to a user. It may be difficult for a user to determine if two interconnected components are secured together by a one-time snap or a snap designed for multiple cycles. It may be difficult for a user to determine that a tool may be needed to disassemble the components. This may lead to the user using excessive force to disassemble the components, which could lead to damage to the components, in particular to the snap or snaps holding the components together. The process may also require the use of two hands. For example, a first hand may be required to apply a separation force to the components, while a second may be required to disengage the snap or snap mechanisms, possibly by using a tool.
[0006] Cooling ducts are commonly used in electronic assemblies where airflow control is desired. For example, many personal computers have ductwork associated with creating a particular airflow path around specific components such as Central Processing Units (CPUs) and memory units. Often, these ducts are secured in place using screws or clips. The ducts may be secured to a heat sink or fan that, in turn, may be interconnected to a CPU or other heat-generating device. Some are secured using snap together designs. However, these snap together designs typically do not provide for easy assembly and disassembly. For example, the duct and the device to which it is attached may both be required to be removed before the duct may be separated. Tools may be required to remove known ducts. Known ducts may be secured using one-time snaps that may be damaged upon removal, requiring replacement parts or additional repair work. Known ducts may require extensive examination to determine how to remove the duct without causing damage. This may be particularly true for a purchaser of the electronic assembly who may be unfamiliar with the duct fastening method.
[0007] The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
SUMMARY
[0008] The following embodiments and aspects of thereof are described and illustrated in conjunction with systems and methods which are meant to be exemplary and illustrative, and not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
[0009] In an aspect, a snap apparatus for attachment to and removal from a mating member without the use of tools includes a snap, a first grip member, an interconnection member, a base, a flexible member, and a second grip member. The first grip member may include a first grip member actuation surface and the second grip member may include a second grip member actuation surface. The interconnection member may be rigidly interconnected to the snap and the first grip member. The flexible member may be interconnected to and disposed between the base and the interconnection member. The first grip member actuation surface may be oriented to face in a substantially opposite direction from the second grip member actuation surface.
[0010] In an embodiment, the interconnection member may be operable to rotate relative to the base. The flexible member may be operable to torsionally flex when the interconnection member is rotated relative to said base. In an embodiment, the first grip member actuation surface may be oriented relative to the second grip member actuation surface to allow for a finger of a hand to engage one of the first grip member actuation surface and the second grip member actuation surface while a thumb of the hand simultaneously engages the other of the first grip member actuation surface and the second grip member actuation surface in a pinching motion. Such a pinching motion may cause the snap to disengage with a mating member. The pinching motion may result in rotation of the interconnection member wherein the first grip member actuation surface may be moved toward the second grip member actuation surface and the snap may be moved away from the second grip member actuation surface.
[0011] In an embodiment, the first grip member actuation surface and/or the second grip member actuation surface may be concave. Furthermore, the surfaces may be textured to assist in gripping the surfaces or may included features that may indicate to a user the function of the grip members. The first grip member actuation surface and the second grip member actuation surface may be operable to be pinched together with a pinching force of less than 4.5 kgf. A radius of curvature of both of the first grip member actuation surface and the second grip member actuation surface may be selected to comfortably fit a finger and/or thumb of a user engaging the surfaces. Such a radius may be greater than 4 mm.
[0012] In an embodiment of the present aspect, a stopper may be included. The stopper may be rigidly interconnected to the base and disposed to prevent the interconnection member from being displaced beyond a maximum predeterminable displacement when the finger and thumb pinch the first grip member actuation surface and the second grip member actuation surface toward each other.
[0013] In an embodiment, the snap may include an engagement surface extending perpendicular to the interconnection member.
[0014] In an embodiment, the snap apparatus may include a guiding member, wherein the guiding member may be slidably engageable with a mating member guiding member, wherein slidably engaging the guiding member with the mating member guiding member restricts motion of the snap apparatus relative to the mating member to a linear motion perpendicular to the engagement surface.
[0015] In an embodiment, the snap of the snap apparatus may be substantially rigid. In an embodiment, the snap engagement of the snap apparatus with the mating member may include the engagement surface in a face-to-face relation with a mating engagement surface on the mating member.
[0016] In an embodiment, the snap apparatus may be operable to withstand a force of 15 kgf oriented perpendicular to the engagement surface and applied to the engagement surface without damage or disengagement.
[0017] In an embodiment, the snap may include an installation displacement surface, wherein the installation displacement surface may be operable to slidably interact with the mating member during installation of the snap apparatus onto the mating member, wherein the interaction may be operable to displace the snap in a direction substantially parallel to the engagement surface.
[0018] In an embodiment, the interconnection member may include two guide walls disposed parallel to each other, perpendicular to the engagement surface and substantially perpendicular to the first grip member actuation surface.
[0019] In an embodiment, the flexible member may include two flexible arms disposed on opposite sides of the interconnection member.
[0020] In another aspect, a method of removal of a snap apparatus from a mating member includes gripping, with a finger of a hand and a thumb of the hand, a first grip member actuation surface and a second grip member actuation surface of the snap apparatus, pinching together, with the finger and the thumb, the first grip member actuation surface and the second grip member actuation surface, and moving an entirety of the snap apparatus with the hand while maintaining the pinching. The first grip member actuation surface may be oriented to face in a substantially opposite direction from the second grip member actuation surface.
[0021] In an embodiment, the first grip member actuation surface and/or the second grip member actuation surface may be concave. The surfaces may be textured to assist in gripping the surfaces or may included features that may indicate to a user the function of the grip members. The first grip member actuation surface and the second grip member actuation surface may be operable to be pinched together with a pinching force of less than 4.5 kgf. A radius of curvature of both of the first grip member actuation surface and the second grip member actuation surface may be selected to comfortably fit a finger and/or thumb of a user engaging the surfaces. Such a radius may be greater than 4 mm.
[0022] In an embodiment, the pinching step may include rotating a snap of the snap apparatus about a rotational axis, wherein the rotation results in the snap moving away from the second grip member actuation surface. In such an embodiment, the rotating step may include moving an engagement surface of the snap from a first position to a second position, wherein in the first position, the engagement surface may be in contact with a surface of the mating member and wherein in the second position, the engagement surface may be free from contact with the surface of the mating member.
[0023] In yet another aspect, an electronic component cooling duct operable to be attached to and removed from an electronic component without the use of tools includes a duct member, a first grip member flexibly interconnected to the duct member and a second grip member rigidly interconnected to the duct member. The duct member may include a plurality of duct walls, which at least partially define a cooling medium flow path. The first grip member may include a first grip member actuation surface and the second grip member may include a second grip member actuation surface. The first grip member actuation surface may be oriented to face in a substantially opposite direction from the second grip member actuation surface. The electronic component cooling duct may include any of the features of embodiments of the above-described snap apparatus.
[0024] In an embodiment of the electronic component cooling duct, the first grip member actuation surface may be oriented relative to the second grip member actuation surface to allow for a finger of a hand to engage one of the first grip member actuation surface and the second grip member actuation surface while a thumb of the hand simultaneously engages the other of the first grip member actuation surface and the second grip member actuation surface in a pinching motion.
[0025] The first grip member actuation surface and/or the second grip member actuation surface may be concave. Furthermore, the surfaces may be textured to assist in gripping the surfaces or may included features that may indicate to a user the function of the grip members. The first grip member actuation surface and the second grip member actuation surface may be operable to be pinched together with a pinching force of less than 4.5 kgf. A radius of curvature of both of the first grip member actuation surface and the second grip member actuation surface may be selected to comfortably fit a finger and/or thumb of a user engaging the surfaces. Such a radius may be greater than 4 mm.
[0026] In an embodiment of the present aspect, the pinching motion may move the snap away from the second grip member actuation surface.
[0027] In an embodiment of the present aspect, the electronic component cooling duct may be operable to withstand a force of 15 kgf oriented perpendicular to the engagement surface and applied to the engagement surface without damage or disengagement.
[0028] In still another aspect, a method of removal of an electronic component cooling duct from a mating component without the use of tools includes gripping, with a finger of a hand and a thumb of the hand, a first grip member actuation surface and a second grip member actuation surface of the electronic component cooling duct, pinching together, with the finger and the thumb, the first grip member actuation surface and the second grip member actuation surface to release a snap of the electronic component cooling duct from engagement with the mating component and moving an entirety of the electronic component cooling duct relative to the mating component with the hand while maintaining the pinching. The first grip member actuation surface may be oriented to face in a substantially opposite direction from the second grip member actuation surface.
[0029] In an embodiment of the present aspect, the first grip member actuation surface and/or the second grip member actuation surface may be concave. The first grip member actuation surface and the second grip member actuation surface may be operable to be pinched together with a pinching force of less than 4.5 kgf. A radius of curvature of both of the first grip member actuation surface and the second grip member actuation surface may be selected to comfortably fit a finger and/or thumb of a user engaging the surfaces. Such a radius may be greater than 4 mm.
[0030] In an embodiment of the present aspect, the pinching step may further include rotating a snap of the electronic component cooling duct about a rotational axis, wherein the rotation results in the snap moving away from the second grip member actuation surface. In such an embodiment, the rotating step may include moving an engagement surface of the snap from a first position to a second position. In the first position, the engagement surface may be in contact with a surface of the mating component and in the second position, the engagement surface may be free from contact with the surface of the mating component.
[0031] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein be considered illustrative rather than limiting.
[0033] FIG. 1 is an illustration an embodiment of a snap apparatus and a mating member positioned relative to each other prior to engagement.
[0034] FIG. 2 is an illustration of the snap apparatus of FIG. 1 engaged with the mating member of FIG. 1 .
[0035] FIG. 3 is a cross-sectional view of the snap apparatus and mating member of FIG. 2 .
[0036] FIG. 4 is a cross-sectional view of the snap apparatus and mating member of FIG. 2 at intermediate positions during the process of engagement with each other.
[0037] FIG. 5 is a cross-sectional view of the snap apparatus and mating member of FIG. 4 at intermediate positions subsequent to the positions illustrated in FIG. 4 during the process of engagement with each other.
[0038] FIG. 6 is a cross-sectional view of the snap apparatus and mating member of FIG. 2 at intermediate positions during the process of disengagement with each other along with a hand of a user.
[0039] FIG. 7 is an illustration of an embodiment of an electronic component cooling duct.
[0040] FIG. 8 is a flowchart of an embodiment of a method of removing a snap apparatus from a mating member.
[0041] FIG. 9 is a flowchart of an embodiment of a method of removing an electronic component cooling duct from a mating component.
DETAILED DESCRIPTION
[0042] Reference will now be made to the accompanying drawings, which assist in illustrating various pertinent features of embodiments of the present invention. Although the embodiments will be described partially in conjunction with an electronic component cooling duct, it should be expressly understood that embodiments of the present invention may be applicable to other applications where it is desired to interconnect and separate components without the use of tools. In this regard, the following description of a snap apparatus in general and an electronic component cooling duct in particular are presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the following teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described herein are further intended to explain modes known of practicing embodiments of the invention and to enable others skilled in the art to utilize embodiments of the invention in such, or other embodiments and with various modifications required by the particular application(s) or use(s) of embodiments of the present invention.
[0043] FIG. 1 is an illustration an embodiment of a snap apparatus 100 and a mating member 150 positioned relative to each other prior to engagement. To engage the snap apparatus 100 with the mating member 150 , the snap apparatus 100 , in the orientation illustrated in FIG. 1 , may be moved straight down along a path 120 toward the mating member 150 . This is described in detail below. Features on both the snap apparatus 100 and the mating member 150 may interact with each other to restrict motion of the snap apparatus 100 relative to the mating member 150 . For example, such features may restrict the motion of the snap apparatus 100 relative to the mating member 150 to an up and down motion as illustrated by the path 120 .
[0044] The snap apparatus 100 of FIG. 1 may be a component or a part of a larger apparatus. Similarly, the mating member 150 may be a component or a part of a larger apparatus. For example, the snap apparatus 100 may be part of a compartment lid and the mating member 150 may be part of a storage bin. Also for example, and as described in detail below, the snap apparatus 100 may be part of an electronic component cooling duct and the mating member 150 may be part of an electronic component cooling fan apparatus. Indeed, given the vast variety of applications of snaps as described above, the snap apparatus 100 and the mating member 150 may be integrated into a wide variety of applications.
[0045] The snap apparatus 100 may include a base 101 that, as described above, may be part of a larger apparatus. The snap apparatus 100 may also include a snap 103 . Generally, the snap 103 may include an engagement surface 111 , as shown in FIG. 3 . The engagement surface 111 may be oriented so that it is perpendicular to the direction of relative motion between the snap apparatus 100 and the mating member 150 .
[0046] The snap 103 may in turn be interconnected to an interconnection member 102 . The interconnection member may be rigid and provide an interconnection between the snap 103 and a flexible member. In the embodiment illustrated in FIG. 1 , the flexible member is in the form of a pair of flexible arms 104 a and 104 b , which flexibly interconnect the interconnection member 102 and the base 101 . As described below, the pair of flexible arms 104 a and 104 b allow for relative motion between the interconnection member 102 and the base 101 .
[0047] The interconnection member 102 may include a first grip member 105 . The first grip member 105 may be configured to interact with a finger of a user. Similarly, the base 101 may include a second grip member 106 configured to interact with a finger of the user. The interconnection member 102 may also include one or more guide walls such as guide wall 108 that may be operable to, in part, guide the motion of the interconnection member 102 relative to the base 101 .
[0048] The base 101 may include features to locate it relative to the mating member 150 when the snap apparatus 100 is engaged with the mating member 150 . In this regard, guide rails 109 a and 109 b may interact with features on the mating member 150 to locate the snap apparatus 100 relative to the mating member 150 . Additionally, the base 101 may include bracing surfaces 110 a and 110 b that may interact with complementary surfaces on the mating member 150 to position the snap apparatus 100 relative to the mating member 150 so that the snap 103 has a predetermined degree of preload against a mating feature of the mating member 150 .
[0049] The snap apparatus 100 and the mating member 150 may be constructed from a wide variety of materials. For example, the snap apparatus 100 and the mating member 150 may be made of plastic, as is typical of many components, such as many consumer electronics devices, that utilize snaps. In this regard, particular components of the snap apparatus 100 and the mating member 150 may be configured differently for different materials. For example, a snap apparatus 100 made from a relatively flexible material may require flexible arms 104 a and 104 b with a greater cross-sectional area to achieve the same degree of flexibility than that of a snap apparatus 100 made from a relatively rigid material.
[0050] The mating member 150 may include a mating engagement feature 151 that may interact with the snap 103 to restrict motion of the snap apparatus 100 relative to the mating member 150 . The mating member 150 may include an open area 152 that may provide for clearance to allow movement of the snap 103 and the interconnection member 102 during engagement and disengagement of the snap apparatus 100 with the mating member 150 . Furthermore, the mating member 150 may include a guide block 153 to aid in guiding the motion of the interconnection member 102 relative to the base 101 during engagement and disengagement of the snap apparatus 100 with the mating member 150 . The mating member 150 may include mating member guide rails 154 a and 154 b that may interact with the guide rails 109 a and 109 b of the snap apparatus 100 to locate the snap apparatus 100 relative to the mating member 150 . Additionally, the mating member 150 may include mating member bracing surfaces 155 a and 155 b that may interact with the bracing surfaces 110 a and 110 b of the snap apparatus 100 .
[0051] FIG. 2 is an illustration of an assembly 200 that includes the snap apparatus 100 of FIG. 1 engaged with the mating member 150 of FIG. 1 . In FIG. 2 , the snap 103 is engaged with the mating engagement feature 151 . This engagement is illustrated in FIG. 3 , which is a cross-section of the assembly 200 along section line A-A of FIG. 2 .
[0052] FIG. 3 illustrates the snap apparatus 100 engaged with the mating member 150 in a manner where movement of the snap apparatus 100 is restricted with respect to the mating member 150 . In this regard, the snap 103 is engaged with the mating engagement feature 151 wherein the engagement surface 111 of the snap 103 is in a face-to-face relationship with an engagement surface 302 of the mating engagement feature 151 . Such an arrangement of two parallel surfaces results in little or no torsional force being applied to the interconnection member 102 when an upward force (upward relative to the orientation of FIG. 3 ) is applied to the snap apparatus 100 . Accordingly, the snap 103 may not disengage from the mating engagement feature 151 when such an upward force is applied. Additionally, such an arrangement may help to prevent accidental or unintentional disengagement of the snap apparatus 100 from the mating member 150 .
[0053] Other embodiments may incorporate a different configuration of the engagement surface 111 and/or the engagement surface 302 . For example, in an embodiment, the engagement surface 111 may oriented at an angle relative to how it is illustrated in FIG. 3 . The engagement surface 111 may be angled so that its slopes from the upper left to the lower right, relative to the illustration of FIG. 3 . In such an arrangement, an upward force imparted on the snap apparatus 100 may result in a sideways force to the left (as illustrated in FIG. 3 ) imparted on the snap 103 as the sloped engagement surface of the snap 103 interacts with the mating engagement feature 151 . This may result in a sideways displacement of the snap 103 and eventually disengagement of the snap 103 from the mating member 150 .
[0054] Conversely, if the engagement surface 111 and the engagement surface 302 are both angled opposite to as previously described, an upwards force imparted on the snap apparatus 100 may result in a sideways force to the right (as illustrated in FIG. 3 ) imparted on the snap 103 which may enhance the ability of the assembly 200 to resist unintentional disengagement between the snap apparatus 100 and the mating member 150 due to an upwards (as illustrated in FIG. 3 ) force applied to the snap apparatus 100 .
[0055] Returning to FIG. 2 , the guide rails 109 a and 109 b may interact with the mating member guide rails 154 a and 154 b to prevent lateral motion of the snap apparatus 100 relative to the mating member 150 . As illustrated in FIG. 2 , the guide rails 109 a and 109 b of the snap apparatus 100 are position along the outside edges of mating member guide rails 154 a and 154 b . It will be appreciated that the relative position of the guide rails 109 a and 109 b and the mating member guide rails 154 a and 154 b may be reversed without a loss of functionality.
[0056] The bracing surfaces 110 a and 110 b of the snap apparatus 100 may interact with the mating member bracing surfaces 155 a and 155 b such that the snap 103 is pressed against the mating engagement feature 151 of the mating member 150 . This may be achieved by selecting a distance between the front surface 303 (as shown in FIG. 3 ) of the snap 103 when the snap 103 is free from external forces and the bracing surfaces 110 a and 110 b that is slightly greater than the distance between the mating engagement feature 151 and the mating member bracing surfaces 155 a and 155 b . Such an arrangement may prevent the snap apparatus 100 from moving or vibrating relative to the mating member 150 . This may, for example, help to prevent rattling between the snap apparatus 100 and the mating member 150 .
[0057] An embodiment of a process of engaging the snap apparatus 100 with the mating member 150 and related features will now be discussed with reference to FIGS. 2 , 3 , 4 and 5 . In the present embodiment, the snap apparatus 100 is moved downward (as illustrated in FIGS. 3 , 4 and 5 ) to engage with and interconnect to the mating member 150 . This movement may be confined to a downward movement by the interaction between a feature or features interconnected to the snap apparatus 100 and a feature or the features interconnected to the mating member 150 . FIG. 7 and its related discussion below describe one example of such an interaction.
[0058] Returning to FIG. 4 , a cross-sectional view with the cross section being taken in the same plane as in FIG. 3 , the interaction between the snap apparatus 100 and the mating member 150 during the process of engagement is illustrated. In FIG. 4 , the initial contact between the snap 103 and the mating engagement feature 151 is illustrated. The snap 103 includes a sloped surface 401 and the mating engagement feature 151 includes a complementary sloped surface 402 .
[0059] As shown in FIG. 5 , as the snap apparatus 100 is lowered, the sloped surface 401 interacts with the complementary sloped surface 402 causing the snap 103 and the entire interconnection member 102 to rotate clockwise generally about the rotational axis 201 (shown in FIG. 2 ). It is noted that the exact position of the rotational axis 201 may vary from that illustrated in FIG. 2 . Additionally, the rotational axis 201 may vary as a function of the rotation of the interconnection member 102 and/or the movement of the interconnection member 102 relative to the base 101 may include a translational component. A resistance to the rotation of the interconnection member 102 is provided by the flexible arms 104 a and 104 b . As the interconnection member 102 rotates relative to the base 101 , the flexible arms 104 a and 104 b experience a torsional flexure.
[0060] Once the tip 501 of the snap 103 clears the engagement surface 302 of the mating engagement feature 151 , the torsional flexure of the flexible arms 104 a and 104 b will cause the snap 103 to snap into the engaged position as illustrated in FIG. 3 . A bottom surface 304 of the base 101 may come into contact with a top surface 305 of the mating engagement feature 151 to prevent the snap apparatus 100 from moving substantially beyond the point where the snap 103 fully engages with the mating engagement feature 151 .
[0061] It will be appreciated that the above-described motion of engagement of the snap apparatus 100 with the mating member 150 may be performed without the use of tools. For example, a user may provide a downward force on the snap apparatus 100 until the tip 501 of the snap 103 clears the engagement surface 302 of the mating engagement feature 151 and the snap 103 snaps into the position illustrated in FIG. 3 .
[0062] During engagement of the snap apparatus 100 with the mating member 150 , a user may intentionally rotate the interconnection member 102 so that the snap 103 does not come into contact with the mating engagement feature 151 during the engagement process. As shown in FIG. 6 , this may be accomplished by the user pinching together the first grip member 105 and the second grip member 106 . For example, the user may place a thumb 601 of a hand 602 into contact with a second grip member actuation surface 606 and a tip of an index finger 603 of the hand 602 into contact with a first grip member actuation surface 605 . The first grip member actuation surface 605 may be an outside facing surface on the first grip member 105 . Similarly the second grip member actuation surface 606 may be an outside facing surface on the second grip member 106 . The first grip member 105 may be rigidly connected to the interconnection member 102 . The second grip member 106 may be rigidly connected to the base 101 . Once the fingers are in position as shown in FIG. 6 , the user may pinch the index finger 603 and a thumb 601 together. This may result in the interconnection member 102 rotating about the rotational axis 201 . This in turn may result in the snap 103 rotating away from the mating engagement feature 151 . Thusly, the user may lower the snap apparatus 100 into the position illustrated in FIG. 6 without the snap 103 contacting the mating engagement feature 151 . If at this point the user were to release the pinching pressure, the interconnection member 102 would rotate into the position as illustrated in FIG. 3 and the snap apparatus 100 and the mating member 150 would be engaged with each other. It is noted that the positions of the thumb 601 and index finger 603 may be reversed or other combinations of fingers may be used to achieve the pinching motion as illustrated in FIG. 6 .
[0063] Additionally, the location of the first grip member 105 with respect to the rotational axis 201 may provide mechanical advantage when pinching the snap apparatus 100 . In this regard, by placing the first grip member 105 on an end of the interconnection member 102 opposite of the snap 103 with the rotational axis 201 between the first grip member 105 and the snap 103 , the interconnection member 102 acts as a lever that provides a mechanical advantage when moving the snap 103 .
[0064] An embodiment of a process of disengaging the snap apparatus 100 from the mating member 150 when they are engaged as illustrated in FIG. 3 will now be described. Returning to FIG. 6 , to disengage the snap apparatus 100 , a user may pinch together the first grip member 105 and the second grip member 106 to move the snap 103 away from the mating engagement feature 151 . Once the snap 103 is clear of the mating engagement feature 151 , the user may pull upward on the snap apparatus 100 to fully disengage the snap apparatus 100 from the mating member 150 .
[0065] The first grip member actuation surface 605 and/or the second grip member actuation surface 606 may be textured or contain other features to enhance the ability of the snap apparatus 100 to be gripped with a pinching motion. As illustrated, the first grip member actuation surface 605 and the second grip member actuation surface 606 may be concave. This concavity may aid in the gripping of the first grip member 105 and the second grip member 106 . The curvature of the concavity may be selected to comfortably interface with a finger or a thumb. Accordingly, the radius of curvature may be at least 4 mm. This concavity and/or any texturing on the first grip member actuation surface 605 and/or the second grip member actuation surface 606 may provide the additional benefit of providing a clear indication to a user of how to grip, install, remove and handle the snap apparatus 100 . Accordingly, the snap apparatus 100 may be installed to and removed from engagement with the mating member 150 without the use of a tool. The snap apparatus 100 may be installed, removed, and handled with one hand. In this regard, the same gripping motion used to disengage the snap 103 from the mating engagement feature 151 may also be used to lift the snap apparatus 100 away from the mating member 150 without the need to reposition the grip on the snap apparatus 100 . This same grip may also be used to handle the snap apparatus 100 .
[0066] As shown in FIG. 1 , the snap apparatus 100 may also include one or more stoppers 107 a and 107 b . As shown in FIG. 6 , when a user pinches together the first grip member 105 and the second grip member 106 , the interconnection member 102 may come into contact with a stopper such as stopper 107 b . The stoppers 107 a and 107 b may serve to prevent a user from displacing the first grip member 105 past a pre-determined point. In this regard, the stoppers 107 a and 107 b may prevent a user from accidentally damaging the snap apparatus 100 . The position of the stoppers 107 a and 107 b and the configuration of the flexible arms 104 a and 104 b may be such that a maximum displacement of the interconnection member 102 as illustrated in FIG. 6 does not result in any permanent damage or deformation of the flexible arms 104 a and 104 b . Without the stoppers 107 a and 107 b , a user may displace the interconnection member 102 beyond the ability of the flexible arms 104 a and 104 b to withstand the displacement without damage.
[0067] The stoppers 107 a and 107 b may serve the function of providing a tactile signal to a user that the interconnection member 102 has been displaced enough so that the snap 103 is clear of the mating engagement feature 151 . For example, a user may pinch the first grip member 105 and the second grip member 106 until the user feels the contact between the interconnection member 102 and the stoppers 107 a and 107 b . The feeling of the contact may serve to signal the user that the snap apparatus 100 is free to be engaged with or disengaged from the mating member 150 without resistance from an interaction between the snap 103 and the mating engagement feature 151 .
[0068] As illustrated in FIG. 1 , the interconnection member 102 may include at least one guide wall 108 and the mating member 150 may include a guide block 153 . The guide walls 108 may be disposed on opposite sides of the interconnection member 102 and may extend parallel to each other and parallel to the direction of motion of the snap apparatus 100 relative to the mating member 150 . The distance between the guide walls 108 may be selected so that the guide walls 108 are disposed on two opposing sides of the guide block 153 when the snap apparatus 100 is engaged with the mating member 150 . In such a configuration, interaction between the guide walls 108 and the guide block 153 when the snap apparatus 100 is engaged with the mating member 150 may limit rotation of the interconnection member 102 about an axis perpendicular to the rotational axis 201 . In this regard, the interaction between the guide walls 108 and the guide block 153 when a user is pinching the first grip member 105 and the second grip member 106 may assist the user in rotating the interconnection member 102 primarily about the rotational axis 201 . This in turn may assist the user in displacing the snap 103 so it is completely clear of the mating engagement feature 151 during engagement or disengagement of the snap apparatus 100 with the mating member 150 .
[0069] FIG. 8 is a flowchart of a method of removing a snap apparatus from a mating member. The method comprises a first step 801 of gripping a first grip member actuation surface and a second grip member actuation surface with a finger and a thumb of a hand, where the grip member actuation surfaces are parts of a snap apparatus. The two surfaces may face in substantially opposite directions from each other. The two surfaces may be concave. The next step 802 may include using the finger and thumb to pinch together the two surfaces. Pinching the two surfaces together may cause a snap of the snap apparatus to rotate in step 803 . In step 804 , the rotation of step 803 may result in moving an engagement surface of the snap from a first position to a second position. In the first position, the engagement surface may be in contact with a surface of a mating member, while in the second position, the engagement surface may be free from contact with the surface of the mating member. Step 805 may include moving the entire snap apparatus relative to the mating member while maintaining the pinching force. This may include moving the snap apparatus away from the mating member.
[0070] FIG. 7 illustrates an exemplary application of a snap apparatus 100 ′ and a mating member 150 ′ that are similar to the snap apparatus 100 and mating member 150 , respectively, of FIG. 1 in an embodiment of a duct and component system 700 . In this embodiment, the snap apparatus 100 ′ is incorporated into an electronic component cooling duct 701 and the mating member 150 is incorporated into an electronic component cooling fan apparatus 702 . The electronic component cooling fan apparatus 702 may for example, be interconnected to a processor of a computer. The electronic component cooling duct 701 may be used to direct airflow from an active component such as the electronic component cooling fan apparatus 702 or it may be used to direct airflow in a passive cooling configuration such as the airflow around a heat sink. The electronic component cooling duct 701 and the outer casing 705 of the electronic component cooling fan apparatus 702 may be made from a plastic such as is typical of cooling ducts found in personal computers.
[0071] The electronic component cooling duct 701 may include a feature, such as guide channel 703 , that may restrict the motion of the electronic component cooling duct 701 relative to the outer casing 705 of the electronic component cooling fan apparatus 702 . This may be accomplished by interaction between the guide channel 703 and a guide rib 704 of the outer casing 705 . As illustrated in FIG. 7 , the guide channel 703 may be configured to interact with the guide rib 704 to restrict the motion of the electronic component cooling duct 701 with respect to the electronic component cooling fan apparatus 702 . As configured in the embodiment illustrated in FIG. 7 , the two components interact to restrict the motion of the electronic component cooling duct 701 , once the guide channel 703 is engaged with the guide rib 704 , to an up and down motion (as oriented in FIG. 7 ). The guide channel 703 may include a lead in section 706 that is wider than the majority of the guide channel 703 . The lead in section 706 may help a user in initially locating the electronic component cooling duct 701 with respect to the electronic component cooling fan apparatus 702 .
[0072] The snap apparatus 100 ′ and the mating member 150 ′ may include any or all of the features discussed above with respect to the snap apparatus 100 and mating member 150 of FIGS. 1 through 6 . In particular, the electronic component cooling duct 701 may be operable to be engaged with or disengaged from the electronic component cooling fan apparatus 702 without the use of tools. This may be accomplished by handling the electronic component cooling duct 701 by pinching the first grip member 105 ′ and the second grip member 106 ′. This pinching may result in a snap (not visible in FIG. 7 ) rotating to a position where it may not interfere with a mating engagement feature 151 ′ of the electronic component cooling fan apparatus 702 when the electronic component cooling duct 701 is installed or removed. The snap apparatus 100 ′ and the mating member 150 ′ may also include features similar to the bracing surfaces, guide walls, and stoppers described above with respect to the snap apparatus 100 and mating member 150 of FIGS. 1 through 6 .
[0073] In one implementation of a duct and component system 700 , the present inventor has determined using finite element analysis that the pinching force required to fully disengage the snap of the snap apparatus 100 ′ from the mating engagement feature 151 ′ may be less than 4.5 kilogram-force (kgf) and that once disengaged, the force required to lift the electronic component cooling duct 701 away from the electronic component cooling fan apparatus 702 may be less than 1 kgf. Furthermore, the force required to fully engage the electronic component cooling duct 701 with the electronic component cooling fan apparatus 702 , without pinching the first grip member 105 ′ and the second grip member 106 ′ (e.g., allowing the snap to interact with the mating engagement feature 151 ′ similar to as shown in FIGS. 4 and 5 ) may be less than 3.5 kgf.
[0074] The duct and component system 700 may be operable to prevent unintended separation of the electronic component cooling duct 701 from the electronic component cooling fan apparatus 702 . For example, the first grip member 105 ′ and in the second grip member 106 ′ present to a user an intuitive interface for removal of the electronic component cooling duct 701 . Given the intuitive nature of the interface, it may be unlikely that a user would accidentally disengage the snap of the snap apparatus 100 ′. Furthermore, without actively disengaging the snap of the snap apparatus 100 ′ from the mating engagement feature 151 ′, a significant amount of the force may be required to disengage the snap apparatus 100 ′ from the mating member 150 ′. For example, in one implementation of a duct and component system 700 , the present inventor has determined using finite element analysis that a duct and component system 700 as described herein may be operable to resist an upward force of 15 kgf applied to the electronic component cooling duct 701 while it is fully engaged with the electronic component cooling fan apparatus 702 without any damage to the system 700 or separation of the individual components.
[0075] Additionally, a user or repair technician that wishes to gain access to the electronic component cooling fan apparatus 702 may be able to quickly discern how to remove the electronic component cooling duct 701 due to the intuitive nature of the interface. This process may also be accomplished without the use of tools. Moreover, the electronic component cooling duct 701 may be operable to be removed from and installed onto the electronic component cooling fan apparatus 702 an unlimited number of times. Also, the electronic component cooling fan apparatus 702 may be accessed by removal of the electronic component cooling duct 701 , whereas in known cooling systems a cooling duct and the device to which it is attached may need to be removed as an assembly before the cooling duct can be removed from the device to which it is attached.
[0076] As discussed above, the snap apparatus 100 ′ may be engaged with the mating member 150 ′ in a manner that includes a pre-determinable amount of a pre-load on the snap of the snap apparatus 100 ′. This preload may aid in the ability of the duct and component system 700 to not rattle when the system 700 experiences vibrations. These vibrations, for example, may be due to shipping or moving the device of which the system 700 is a component, vibrations from other proximal components, or vibrations from a cooling fan within the electronic component cooling fan apparatus 702 .
[0077] FIG. 9 is a flowchart of a method of removing an electronic component cooling duct from a mating component. The method comprises a first step 901 of gripping a first grip member actuation surface and a second grip member actuation surface with a finger and a thumb of a hand, where the grip member actuation surfaces are parts of the electronic component cooling duct. The two surfaces may face in substantially opposite directions from each other. The two surfaces may be concave. The next step 902 may include using the finger and thumb to pinch together the two surfaces. Pinching the two surfaces together may cause a snap of the electronic component cooling duct to rotate in step 903 . In step 904 , the rotation of step 903 may result in moving an engagement surface of the snap from a first position to a second position. In the first position, the engagement surface may be in contact with a surface of the mating component, while in the second position, the engagement surface may be free from contact with the surface of the mating component. Step 905 may include moving the entire electronic component cooling duct relative to the mating component while maintaining the pinching force. This may include moving the electronic component cooling duct away from the mating component.
[0078] It should be understood that the particular values and configurations described herein could be varied and achieve the same objectives. The values and configurations described herein are merely exemplary.
[0079] The foregoing description has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the embodiments and form disclosed herein. While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain variations, modifications, permutations, additions, and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such variations, modifications, permutations, additions, and sub-combinations as are within their true spirit and scope. | An integrated snap and handling apparatus is provided. The apparatus may be capable of being assembled with and disassembled from a mating component without damage. The apparatus may include a pair of features that provide an intuitive and easy user interface for removal, handling and installation. The pair of features may allow a user to use a pinching motion to engage and disengage the apparatus from the mating component without the use of a tool. The integrated snap and handling apparatus may provide for low removal forces when the user interface is properly actuated while resisting high separation forces when the user interface is not properly actuated. The integrated snap and handling apparatus may be incorporated into a wide variety of assemblies and devices. For example, the integrated snap and handling apparatus may be incorporated into a cooling duct for the control of airflow around an electronic component. | 8 |
This is a continuation of copending application Ser. No. 07/687,461 filed on Apr. 18, 1991 now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a novel method for the sizing of paper.
Hitherto, as the method for the sizing of paper, there have mainly been used the so-called acidic sizing methods in which acidic sizing agents such as rosin sizing agents, synthetic sizing agents, etc. and alum are employed. In recent years, the so-called neutral sizing methods in which neutral sizing agents represented by alkyl ketene dimer and alkenylsuccinic anhydride are employed have been developed in order to overcome the defects caused by alum in the acidic sizing methods or to use calcium carbonate, which is a low price filler. However, the neutral sizing methods are disadvantageous in the stability and the costs of the neutral sizing agents. Recently, in the manufacturing industry of the regenerated papers such as white boards, raw papers for gypsum boards and the like from wasted paper containing calcium carbonate, is required in order to meet the needs of conservation of resources a novel papermaking method which can provide papers showing an excellent sizing properties at a low cost by making a paper at around neutrality of pH range from 5.5 to 7.5.
As the acidic sizing methods using rosin sizing agents, there has been known a method disclosed in Japanese Patent Application Laid-Open (KOKAI) 14807/78 in which a paper with good sizing properties is obtained by using a particular Hofmann rearrangement-reaction product as a size-fixing aid. However, this method has defects in that size-fixing is insufficient in the papermaking at around neutrality.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a method for making a paper having an excellent sizing property by making a paper at a pH around neutrality using a known acidic sizing agent which is widely used in the art.
The present inventors have researched in order to solve the above problems in the prior art and have found that the problems can be solved by making a paper using a particular vinylamine polymer as a size-fixing aid. The present invention has been accomplished based on this finding.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a method for sizing of paper which comprises subjecting a mixture comprising an aqueous pulp slurry, an acidic sizing agent, alum and a size-fixing aid to papermaking at a pH value from 5.5 to 7.5, the size-fixing aid being a vinylamine polymer having the constitutional repeating units represented by the following formulae (I), (II) and (III): ##STR1## wherein X represents an anion, R 1 represents a hydrogen atom or a methyl group, and Y represents at least one functional group selected from the group consisting of a cyano group, a carbamoyl group which may be substituted, a carboxyl group and a (C 1 -C 4 alkoxy)carbonyl group, the mol fraction of the unit (I) being 5 to 95 mol %, the mol fraction of the unit (II) being 2 to 95 mol %, and the mol fraction of the unit (III) being 0 to 90 mol %, with the proviso that the mol fraction of the unit (III) is less than the mol fraction of the unit (I) when Y is a carboxyl group.
A vinylamine polymer in which the mol fraction of the unit (I) is 5 to 95 mol %, the mol fraction of the unit (II) is 5 to 95 mol % and the mol fraction of the unit (III) is 0 to 80 mol % is more preferred to be used as the size-fixing aid in the present invention.
The vinylamine polymer used in the present invention may be easily obtained by modifying formyl groups in an N-vinylformamide polymer (homopolymer and copolymer) under acidic or basic conditions. The homopolymer of N-vinylformamide as a starting material is prepared by polymerizing N-vinylformamide in the presence of a radical polymerization initiator. The copolymer of N-vinylformamide as a starting material is prepared by polymerizing in the presence of a radical polymerization initiator a monomer mixture comprising 10 mol % or more, preferably 20 mol % or more, of N-vinylformamide and a compound represented by the following formula (IV): ##STR2## wherein R 1 represents a hydrogen atom or a methyl group, Y represents at least one functional group selected from the group consisting of a cyano group, a carbamoyl group which may be substituted, a carboxyl group and a (C 1 -C 4 alkoxy)carbonyl group. The preferred compound of the formula (IV) may include acrylonitrile, C 1 -C 4 alkyl (meth)acrylates, acrylamide and (meth)acrylic acid, and acrylonitrile and acrylamide are most preferable.
As a polymerization method for producing the N-vinylformamide polymer, a bulk polymerization, a solution polymerization using various solvents and a precipitation polymerization process using various solvents may be adopted. Among these methods, a polymerization method using water as a polymerization solvent is preferable. In polymerizing a monomer by a solution polymerization method, the concentration of monomer, the polymerization method and the shape of a polymerization vessel are appropriately selected in consideration of the molecular weight of the polymer to be produced and of the polymerization heats to be evolved.
For example, when water is used as a polymerization solvent, the N-vinylformamide polymer can be produced by a method in which the polymerization is initiated in a solution form at a monomer concentration of 5 to 20 weight % to produce a polymer in a solution form; a method in which the polymerization is initiated at a monomer concentration of 20 to 60 weight % to produce a polymer as a wet gel-like product or as a polymer precipitate; a method in which an aqueous solution of a monomer concentration of 20 to 60 weight % is subjected to polymerization in water-in-oil or oil-in-water emulsion state by using a hydrophobic solvent and an emulsifying agent; or a method in which an aqueous monomer solution of a monomer concentration of 20 to 60 weight % is subjected to polymerization in a water-in oil dispersion state by the use of a hydrophobic solvent and a dispersion stabilizer. In copolymerization with acrylonitrile, the N-vinylformamide polymer may be obtained as a precipitated product in water.
As the radical polymerization initiator, there may be employed any of usual initiators used for the polymerization of a water-soluble or hydrophilic monomer. For obtaining the polymer in a higher yield, azo compounds are preferable, and water-soluble azo compounds are more preferable. For example, there are used hydrochloride or acetate of 2,2'-azobis-2-amidinopropane, sodium salt of 4,4'-azobis-4-cyanovaleric acid, and hydrochloride or acetate of azobis-N,N'-dimethyleneisobutylamidine. The polymerization initiator is usually used in an amount from 0.01 to 1% by weight based on the weight of the monomer. The polymerization reaction is carried out at a temperature of 30° to 100° C. under an inert gas stream.
The N-vinylformamide polymer obtained as described above is modified under acidic or basic conditions to obtain the vinylamine polymer in solution or dispersion directly after the polymerization followed or not followed by dilution. The modification can be carried out after separation of the N-vinylformamide polymer followed by removing water, drying and pulverizing by a known method.
However, when the N-vinylformamide polymer to be modified contains the units (III) wherein Y is a cyano group, a carbamoyl group or a alkoxycarbonyl group in a large amount, the modification under basic condition is not preferred. It is because in the basic hydrolysis of the formyl group in water, the cyano group, carbamoyl group and alkoxycarbonyl group are also hydrolysed to form a large excess of carboxyl groups, thereby resulting in the production of an insoluble polymer or the production of an ampholytic polymer containing a large number of anionic groups.
As a method for modifying the N-vinylformamide polymer, there are exemplified an acidic or basic hydrolysis in water, an acidic or basic hydrolysis in a water-containing hydrophilic solvent such as alcohol, and a method in which the formyl group is subjected to alcoholysis and the modification is carried out under separating the resulting formic ester from the system. Alcohols having 1 to 4 carbon atoms, preferably methanol, may be used in the alcoholysis.
As the modifying agent used in the acidic modification, there may be used any of the compounds acting as a strong acid, for example, hydrochloric acid, bromic acid, hydrofluoric acid, sulfuric acid, nitric acid, phosphoric acid, sulfamic acid, alkanesulfonic acids, and the like. As the modifying agent used in the basic modification, there may be used any of the compounds acting as a strong base in water, for example, sodium hydroxide, potassium hydroxide, quaternary ammonium hydroxides and the like.
The modifying agent is used in an amount appropriately selected from the range from 0.1 to 2 mol per one mol of the formyl group in the N-vinylformamide polymer depending upon the intended extent of the modification.
As the result of the modification, X in the unit (I) of the vinylamine polymer represents an acid radical such as halogen ion, sulfate ion, etc. corresponding to the acid used as the modifying agent in the case of the acidic modification, and X represents hydroxyl ion in the case of the basic modification.
The modification is carried out at a temperature from 10° to 100° C. The molecular weight of the vinylamine polymer is not otherwise limited, but usually the reduced viscosity of the vinylamine polymer is 0.1 to 10 dl/g, preferably 0.5 to 10 dl/g, the reduced viscosity being measured at 25° C. on a 0.1 g/dl solution in 1N-brine. When the reduced viscosity is less than 0.1 dl/g, the size-fixing properties tends to be decreased. When the reduced viscosity exceeds 10 dl/g, the workability tends to become lower owing to the high viscosity.
The vinylamine polymer obtained by the above process is used as a size-fixing aid in accordance with the following method, and it imparts a superior sizing effect to a produced paper.
The acidic sizing agent used in the present invention is not otherwise limited, and may include any of various known sizing agents, for example, rosin sizing agents and synthetic sizing agents. The rosin sizing agent may include one in which rosin substance is dissolved or dispersed in water by an appropriate means, and it may include an aqueous solution-type rosin sizing agent neutralized with alkali and an emulsion-type rosin sizing agent emulsified with various surface active agents or with water-soluble polymers. The rosin substance may include rosins such as gum rosin, wood rosin, tall oil rosin, hydrogenated rosin, disproportioned rosin, polymerized rosin, aldehyde-modified rosin and rosin ester, and reaction product of the rosin recited above and an α,β-unsaturated carboxylic acid such as acrylic acid, maleic anhydride, fumaric acid itaconic acid and the like.
The surface active agent or water-soluble polymer used in the emulsion-type rosin sizing agent may include a rosin substance neutralized with alkali, a salt of alkylbenzenesulfonic acid, a monoalkyl sulfate, polyethylene glycol, a polyoxyethylene alkyl ether, a polyoxyethylene alkyl phenyl ether, a polyoxyethylene alkyl ether sulfate salt, a polyoxyethylene alkyl ether sulfonate salt, a polyoxyethylene alkyl ether sulfosuccinate salt, polyvinyl alcohol, polyacrylamide, a copolymer of a hydrophobic monomer such as styrene compound, lower alkyl (meth)acrylates, etc. and an anionic monomer such as (meth)acrylic acid, etc., shellac, casein, and the like.
The synthetic sizing agent may include a reaction product of an olefin having 8 to 20 carbon atoms and an α,β-unsaturated carboxylic acid. The olefin having 8 to 20 carbon atoms may include octene, dodecene, tetradecene, octadecene, and the like. The α,β-unsaturated carboxylic acid may include acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, itaconic acid and the like. The typical example of the reaction product is a water-soluble salt of a substituted succinic acid, more precisely, a water-soluble salt of an alkenylsuccinic anhydride such as octenyl succinic anhydride, dodecenyl succinic anhydride, and the like. The synthetic sizing agents are described in more detail in Japanese Patent Publication (KOKOKU) No. 565/65.
In practical application of the paper sizing method of the present invention, the various known processes are adopted except for adjusting the pH to the specific range and using the vinylamine polymer as a size-fixing aid in papermaking process. For example, to an aqueous pulp slurry, are added 0.05 to 2% by weight (based on pulp solid) of an acidic sizing agent, 0.1 to 5% by weight (based on pulp solid) of alum and 0.005 to 0.5% by weight of the vinylamine polymer as a size-fixing aid, and then the conventional papermaking method is applied while adjusting the pH to the range from 5.5 to 7.5. The order of the addition is not otherwise limited. Usually, a sizing agent and alum are added to a pulp slurry, and then a size-fixing aid is added thereto. The kinds of pulps are not particularly limited, and various known pulps may be used optionally. Pulps may include ground pulp, semi-ground pulp, sulfite pulp, semi-chemical pulp, kraft pulp, as well as regenerated pulps prepared by defibering wasted papers. The above pulps are used along or in combination.
Since the paper sizing method of the present invention is carried out at around neutrality, it is usual that the pH of the papermaking system is adjusted by appropriately selecting the amount of alum and the amount of an alkaline filler such as calcium carbonate. As described above, wasted papers containing calcium carbonate may be used as the starting pulp in the paper sizing method of the present invention, and the use of such wasted paper is advantageous in view of the paper production costs and conservation of resources. The type of calcium carbonates are not otherwise limited, and it may include various known calcium carbonates such as ground calcium carbonate, precipitated calcium carbonate and the like. Such calcium carbonate may be contained in the starting pulp in an amount not higher than 30 weight %.
Hereinafter, the present invention will be described in more detail by Production Examples, Examples and Comparative Examples. However, it should be noted that the present invention is not limited by these Examples.
Production Example 1
A reaction vessel equipped with a stirrer, a nitrogen inlet tube and a condenser was charged with 4.0 g of N-vinylformamide or 4.0 g of a respective monomer mixture listed in Table 1, and 35.9 g of desalted water. The content was heated to 60° C. with stirring under a nitrogen stream, and was added with 0.12 g of an aqueous 10% (by weight) solution of 2,2'-azobis-2-amidinopropane dihydrochloride. The content was held at 60° C. for 3 hours under stirring to obtain a polymer. The unreacted monomer or monomers remaining in water was measured by liquid chromatograph or gas chromatograph to determine the composition of the obtained polymer.
The obtained polymer was added with conc. hydrochloric acid in an amount equivalent to the formyl groups in the polymer, and was maintained at 75° C. for 8 hours under stirring to hydrolyse the polymer.
The obtained polymer solution was added into acetone to form a precipitate. After vacuum drying the precipitated polymer, a vinylamine polymer was obtained in a solid form. The mol fraction of the compound (IV) in the monomer mixture, colloid equivalent, the result of elemental analysis, the mol fraction of the constitutional units in the obtained vinylamine polymer determined by 13 C-NMR spectrum, and reduced viscosity of the obtained vinylamine polymer are shown in Table 1.
The colloid equivalent and reduced viscosity were measured by the methods described hereinafter.
Colloid equivalent
A solid polymer was dissolved in distilled water to prepare a 0.1 weight % aqueous polymer solution. 5.0 g of the aqueous polymer solution was diluted to 200 ml with deionized water, then adjusted to pH 3 with dil. hydrochloric acid. The colloid equivalent was determined by colloid titration method using 1/400N potassium polyvinyl sulfate and using toluidine blue as an indicator.
Reduced viscosity
A solid polymer is dissolved in 1N-brine to prepare a polymer solution of a concentration of 0.1 g/dl. The reduced viscosity was measured at 25° C. by using a Ostwald viscometer.
Reduced viscosity (dl/g)=(t-t.sub.0)/t.sub.0 /0.1
t 0 : falling speed of brine
t: falling speed of polymer solution
TABLE 1__________________________________________________________________________ Mol fraction of the units in vinylamine polymer (mol %) Mol fraction of the III ReducedVinylamine compound (IV) in the R.sub.1 R.sub.1 = H viscositypolymer monomer mixture I II Y Y = CONH.sub.2 (dl/g)__________________________________________________________________________A 0 56 44 0 0 0.5B 0 50 50 0 0 2.9C 0 50 50 0 0 4.3D 0 48 52 0 0 5.5E 0 52 48 0 0 6.1F 0 6 94 0 0 5.9G 0 21 79 0 0 4.9H 0 31 69 0 0 4.4I 0 78 22 0 0 3.9J 0 95 5 0 0 3.6K AN 0.8 16 4 61*.sup.1 19 2.9L AN 0.5 40 10 38*.sup.1 12 2.6M MMA 0.1 61 29 10*.sup.2 0 2.5N DAA 0.2 64 16 20*.sup.3 0 3.0__________________________________________________________________________ Note: AN: acrylonitrile, MMA: methyl methacrylate, DAA: diacetone acrylamide *.sup.1 R.sub.1 = H, Y = CN *.sup.2 R.sub.1 = CH.sub.3, Y = COOCH.sub.3 *.sup.3 R.sub.1 = H, Y = CONHC(CH.sub.3).sub.2 CH.sub.2 COCH.sub.3
EXAMPLES 1-14
A predetermined amount of alum was added to 1 weight % slurry of pulp (L-BKP, Canadian Standard Freeness of 485 ml), and was agitated for 5 min.
A rosin emulsion sizing agent (trade name: Sizepine N-705, manufactured by Arakawa Kagaku Kogyo Co.) was added thereto in an amount of 0.2% by weight (as solid) based on pulp, and further agitated for 5 min. Then, respective vinylamine polymer (polymers A-N described in Table 1) as size-fixing aid was added thereto in an amount described in Table 2 and further agitated for 5 min. Using each of pulp slurries, each of sheets of paper was made at a pH value described in Table 2 by means of a TAPPI Standard Sheet Machine. The formed wet paper was dehydrated under a pressure of 3.5 kg/cm 2 , and dried at 100° C. for 1 min. The dried paper was conditioned at 20° C. and at 65% RH for at least 24 hours, the Stockigt sizing degree thereof was tested in accordance with the method described in Japanese Industrial Standard (JIS) P 8122.
The results are shown in Table 2. As seen from the results in Table 2, the present method shows excellent results irrespective of pH values. Especially, the superiority of the present method to the methods in Comparative Examples 1 to 3 is remarkable in the pH range of 5.5 to 7.5.
COMPARATIVE EXAMPLE 1
A dried paper was produced in the same manner as in Example 1 except that a Hofmann rearrangement product (a) of polyacrylamide (produced by subjecting a polyacrylamide of a molecular weight of 300,000 to Hofmann rearrangement to change 20 mol % of the acrylamide units into the vinylamine units) was used as a size-fixing aid. The results are shown in Table 2.
COMPARATIVE EXAMPLE 2
A paper was produced in the same manner as in Example 1 except that a copolymer (b) (reduced viscosity: 1.2 dl/g) of acrylamide and dimethylaminopropylmethacrylamide (mol ratio: 95/5) was used as a size-fixing aid. The results are shown in Table 2.
COMPARATIVE EXAMPLE 3
A paper was produced in the same manner as in Example 1 except that no size-fixing aid was used. The results are shown in Table 2.
EXAMPLES 15-32
To 1 weight % pulp slurry (L-BKP, Canadian Standard Freeness: 450 mol), were added calcium carbonate in an amount of 2% by weight (as solid) based on pulp, then was agitated for 5 min. After the agitation, was added further alum in an amount of 0.5% by weight based on pulp and was agitated for additional 5 min. Finally, each of size-fixing aids was added thereto in an amount described in Table 3 and was agitated for 5 min. Using the obtained pulp slurry, each of papers was formed at pH of 7.2 by means of TAPPI Standard Sheet Machine. The resultant wet paper was dehydrated under a pressure of 3.5 kg/cm 2 , and was dried at 100° C. for 1 min. Each of dried papers was conditioned at 20° C. and at 65% RH for at least 24 hours and was tested for a Stockigt sizing degree. The results are shown in Table 3.
(1) Aqueous type fortified rosin sizing agent (trade name Sizepine E, manufactured by Arakawa Kagaku Kogyo Co.)
(2) Alkenylsuccinate type sizing agent (trade name: Sizepine S-300, manufactured by Arakawa Kagaku Kogyo Co.)
(3) Rosin emulsion sizing agent (trade name: Sizepine N-705, manufactured by Arakawa Kagaku Kogyo Co.)
COMPARATIVE EXAMPLES 4-6
Each of papers was produced in the same manner as in Example 15 except that the Hofmann rearrangement product (a) was used as the size-fixing aid. The results are shown in Table 4.
COMPARATIVE EXAMPLES 7-9
Each of papers was produced in the same manner as in Example 15 except that the copolymer (b) was used as the size-fixing aid. The results are shown in Table 4.
COMPARATIVE EXAMPLES 10-12
Each of papers was produced in the same manner as in Example 15 except that no size-fixing aid was used. The results are shown in Table 4.
EXAMPLES 33-50
To 1 weight % pulp slurry (magazine wasted paper containing 4.5% by weight of calcium carbonate; Canadian Standard Freeness: 380 ml), each of the sizing agents listed in Table 5 was added in an amount of 0.5% by weight based on the pulp and was agitated for 5 min. Then alum was added thereto in an amount of 2.0% by weight based on the pulp and further agitated for 5 min. Finally each of size-fixing aids was added in an amount described in Table 5 and was agitated for 5 min. Each of papers was formed at pH of 6.9 by means of TAPPI Standard Sheet Machine. The resultant wet paper was dehydrated under a pressure of 3.5 kg/cm 2 , and was dried for 1 min. at 100° C. Each of dried paper was conditioned at 20° C. and at 65% RH for at least 24 hours, and was tested for Stockigt sizing degree. The results are shown in Table 5.
COMPARATIVE EXAMPLES 13-15
Each of papers was produced in the same manner as in Example 33 except that the Hofmann rearrangement product (a) was used as the size-fixing aid. The results are shown in Table 6.
COMPARATIVE EXAMPLES 16-18
Each of papers was produced in the same manner as in Example 33 except that the copolymer (b) was used as the size-fixing aid. The results are shown in Table 6.
COMPARATIVE EXAMPLES 19-21
Each of papers was produced in the same manner as in Example 33 except that no size-fixing aid was used. The results are shown in Table 6.
TABLE 2______________________________________Stockigt sizing degree (sec) Average basis weight: 60.5 g/m.sup.2 Alum addition amount (%) Addition amount 2.0 1.0 0.5 Size-fixing of size-fixing aid pH aid (%) 4.5 5.5 6.2______________________________________Example 1 A 0.05 -- -- 17.5 0.1 32.8 30.9 24.3 0.2 -- -- 27.8Example 2 B 0.05 -- -- 18.1 0.1 33.6 32.0 25.8 0.2 -- -- 28.7Example 3 C 0.05 -- -- 18.9 0.1 34.2 33.1 26.5 0.2 -- -- 30.0Example 4 D 0.05 -- -- 18.4 0.1 33.5 32.8 26.1 0.2 -- -- 29.6Example 5 E 0.05 -- -- 17.7 0.1 32.7 31.6 24.8 0.2 -- -- 29.1Example 6 F 0.05 -- -- 15.5 0.1 29.6 26.3 23.1 0.2 -- -- 26.4Example 7 G 0.05 -- -- 16.1 0.1 29.9 27.0 24.2 0.2 -- -- 27.2Example 8 H 0.05 -- -- 17.6 0.1 32.1 30.9 25.7 0.2 -- -- 27.9Example 9 I 0.05 -- -- 18.1 0.1 32.4 31.6 25.4 0.2 -- -- 27.5Example 10 J 0.05 -- -- 17.0 0.1 31.6 30.4 24.1 0.2 -- -- 27.2Example 11 K 0.1 34.1 33.6 27.5Example 12 L 0.1 33.8 32.7 27.0Example 13 M 0.1 29.5 27.8 24.3Example 14 N 0.1 28.4 27.1 23.7Comparative a 0.05 -- -- 6.5Example 1 0.1 24.1 18.2 10.3 0.2 -- -- 13.1Comparative b 0.05 -- -- 7.8Example 2 0.1 26.4 21.7 12.6 0.2 -- -- 16.6Comparative None 0 18.5 12.9 2.1Example 3______________________________________
TABLE 3______________________________________Stockigt sizing degree (sec) Average basis weight: 60.5 g/m.sup.2 Additon amount Size-fixing of size-fixing aid Sizing agentExample aid (%) 1 2 3______________________________________Example 15 A 0.05 18.2 -- -- 0.1 21.5 -- --Example 16 A 0.05 -- 17.4 -- 0.1 -- 20.9 --Example 17 A 0.05 -- -- 24.8 0.1 -- -- 28.6Example 18 C 0.05 19.5 -- -- 0.1 22.2 -- --Example 19 C 0.05 -- 18.8 -- 0.1 -- 22.0 --Example 20 C 0.05 -- -- 25.1 0.1 -- -- 29.3Example 21 E 0.05 18.9 -- -- 0.1 21.8 -- --Example 22 E 0.05 -- 17.9 -- 0.1 -- 21.3 --Example 23 E 0.05 -- -- 25.0 0.1 -- -- 28.2Example 24 F 0.05 16.4 -- --Example 25 F 0.05 -- 15.2 --Example 26 F 0.05 -- -- 23.5Example 27 J 0.05 17.7 -- --Example 28 J 0.05 -- 17.1 --Example 29 J 0.05 -- -- 24.4Example 30 L 0.05 19.8 -- --Example 31 L 0.05 -- 18.6 --Example 32 L 0.05 -- -- 25.6______________________________________
TABLE 4______________________________________Stockigt sizing degree (sec) Average basis weight: 60.5 g/m.sup.2 Additon amount Size-fixing of size-fixing aid Sizing agentExample aid (%) 1 2 3______________________________________Comparative a 0.05 3.5 -- --Example 4 0.1 6.1 -- --Comparative a 0.05 -- 2.8 --Example 5 0.1 -- 5.7 --Comparative a 0.05 -- -- 4.0Example 6 0.1 -- -- 8.6Comparative b 0.05 3.8 -- --Example 7 0.1 7.2 -- --Comparative b 0.05 -- 3.2 --Example 8 0.1 -- 6.4 --Comparative b 0.05 -- -- 5.2Example 9 0.1 -- -- 9.5Comparative None 0 0 -- --Example 10Comparative None 0 -- 0 --Example 11Comparative None 0 -- -- 0Example 12______________________________________
TABLE 5______________________________________Stockigt sizing degree (sec) Average basis weight: 62.5 g/m.sup.2 Additon amount Size-fixing of size-fixing aid Sizing agentExample aid (%) 1 2 3______________________________________Example 33 A 0.05 12.4 -- -- 0.1 16.5 -- --Example 34 A 0.05 -- 11.1 -- 0.1 -- 15.9 --Example 35 A 0.05 -- -- 13.6 0.1 -- -- 17.5Example 36 C 0.05 12.8 -- -- 0.1 17.0 -- --Example 37 C 0.05 -- 11.5 -- 0.1 -- 16.3 --Example 38 C 0.05 -- -- 13.9 0.1 -- -- 18.0Example 39 E 0.05 12.6 -- -- 0.1 16.3 -- --Example 40 E 0.05 -- 11.2 -- 0.1 -- 16.1 --Example 41 E 0.05 -- -- 13.5 0.1 -- -- 17.8Example 42 F 0.05 10.4 -- --Example 43 F 0.05 -- 9.8 --Example 44 F 0.05 -- -- 11.5Example 45 J 0.05 11.5 ----Example 46 J 0.05 -- 10.2 --Example 47 J 0.05 -- -- 12.8Example 48 L 0.05 12.6 -- --Example 49 L 0.05 -- 11.2 --Example 50 L 0.05 -- -- 13.8______________________________________
TABLE 6______________________________________Stockigt sizing degree (sec) Average basis weight: 62.5 g/m.sup.2 Additon amount Size-fixing of size-fixing aid Sizing agentExample aid (%) 1 2 3______________________________________Comparative a 0.05 1.5 -- --Example 13 0.1 3.1 -- --Comparative a 0.05 -- 1.0 --Example 14 0.1 -- 2.8 --Comparative a 0.05 -- -- 2.0Example 15 0.1 -- -- 4.3Comparative b 0.05 1.5 -- --Example 16 0.1 3.5 -- --Comparative b 0.05 -- 1.0 --Example 17 0.1 -- 3.0 --Comparative b 0.05 -- -- 2.5Example 18 0.1 -- -- 4.5Comparative None 0 0 -- --Example 19Comparative None 0 -- 0 --Example 20Comparative None 0 -- -- 0Example 21______________________________________ | The present invention relates to a method for sizing of paper by using a particular vinylamine polymer as a size-fixing aid. By the use of the vinylamine polymer as a size-fixing aid, it has become possible to obtain a paper having superior sizing properties by papermaking at a pH around neutrality using a hitherto known acidic sizing agents without using a neutral sizing agent. The method of the present invention further has effects that operating efficiency of papermaking is greatly improved since contaminations of a papermaking machine due to a neutral agent can be avoided, and therefore, the prices of paper can be greatly lowered. The present method has further advantages when it is applied under acidic papermaking condition of a pH of less than 5.5. In such a condition, the addition amount of alum can be decreased and the life of a papermaking machine can be prolonged. In spite of a small amount of alum added, a considerably good sizing effect can be obtained by the present method. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to electrical reversing switches which upon actuation from one condition to another change the direction of current flow through the switch.
Electrical reversing switches are commonly double pole, double throw switches which have their load side terminals cross connected by external jumper wires. This configuration results in a bulky wiring structure at the terminals of the switch. Additionally, switches which have internal press-in wire terminations effected by inserting the bared ends of wire conductors into holes in the housing of the switch do not readily lend themselves to such external jumper cross connections. U.S. Pat. No. 4,683,352 issued July 28, 1987 to Takashi Yano and Yasuo Yoneyama discloses a reversing switch having press-in terminations wherein the cross connection between the load side terminals is accomplished internally of the switch housing. This switch comprises a double pole, double throw toggle mechanism wherein rocking contactors are pivotally supported on a common central contact, the ends of the contactors being pivoted downward into engagement with stationary contacts at one end of each pole of the switch in one position and pivoted downward at the opposite end into engagement with stationary contacts at the other end of each pole of the switch in a second position. Cross connection jumpers are molded integrally within a base member of the switch and are connected to the stationary contacts at the respective ends of each pole. While this switch is useful for its intended purpose, the present invention relates to improvements thereover.
SUMMARY OF THE INVENTION
The present invention provides a reversing switch which is readily and economically manufactured. It comprises a double pole, double throw rocking contactor switch which is actuated by a pivotally mounted actuator which may be operated by a toggle lever or a rocker button. One pole of the switch contains the customary center fulcrum contact on which a rocker contactor is pivotally supported and a pair of stationary contacts located on opposite sides of the fulcrum contact for engagement on their upper surface by the rocking contactor. The other pole of the switch of this invention is substantially the same as the above described pole except it has the stationary contacts spaced above the rocking contactor for engagement at their under surfaces by the upper surface of the rocking contactor. This arrangement provides engagement by the respective rocking contactor with stationary contacts at opposite ends of the two poles in either position of the pivotal actuator. The stationary contacts at corresponding ends of the two poles are formed from common electrically conductive members which have press-in wire termination members associated therewith forming output terminations at the load side of the switch. The invention also provides serrations on a surface of the stationary contact conductive members and the fulcrum contacts for enhancing the press-in wire termination with the respective contact.
The features and advantages of this invention will become more readily apparent when reading the following specification and claims in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the electrical reversing switch of this invention;
FIG. 2 is a right end elevational view of the switch of FIG. 1;
FIG. 3 is a cross sectional view through one pole of the electrical reversing switch of this invention taken generally along the line 3--3 in FIG. 2;
FIG. 4 is a cross sectional view through the other pole of the switch of this invention taken generally along the line 4--4 in FIG. 2;
FIG. 5 is a transverse cross sectional view taken generally along the line 5--5 of FIG. 1 showing an electrically conductive member containing one pair of stationary contacts for the two poles of the switch of this invention;
FIG. 6 is an exploded isometric view of the switch of FIGS. 1-5;
FIG. 7 is an exploded isometric view of a fulcrum contact and wire retaining leaf spring forming an improved press-in wire termination of the switch of this invention;
FIG. 8 is a fragmentary sectional view of the wire termination of FIG. 7; and
FIG. 9 is a bottom elevational view, drawn to a reduced scale, of the switch of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and particularly to FIGS. 1, 2 and 6 thereof, the switch of this invention is a double pole, double throw toggle switch having an insulating housing comprising a molded insulating cover 2 and molded insulating base 4. Cover 2 is telescopically disposed over base 4 and attached thereto with a snap fit by the interengagement of holes 2a (only one visible in FIGS. 2 and 6) in the end walls of cover 2 with beveled cylindrical projections 4a (only one visible in FIGS. 2 and 6) formed on the end walls of base 4. Base 4 has an upstanding central wall 4b extending longitudinally between the end walls thereof to divide the base and the housing into side-by-side switch pole compartments 6 and 8 when the cover 2 is attached to the base 4. The floor 4c of compartment 8 is provided with a slot 4d open to one side of base 4 and communicating with a rectangular pocket 4e in the lower portion of base 4 which is also open to the side of the base 4. A fulcrum contact assembly 10 is received within the slot 4d and the pocket 4e. Contact assembly 10 has a notch 10a along one edge which interlocks with a portion of floor 4c adjacent the end of slot 4d to position contact assembly 10 in an upright manner within the compartment 8. Although not visible in FIG. 6, the floor of compartment 6 is provided with a slot similar to 4d open to the opposite side of base 4 for receiving a fulcrum contact assembly 12 having a notch 12a formed in one edge thereof. Fulcrum contacts 10 and 12 have stepped recesses in their upper edges which provide pivot surfaces 10b and 12b, respectively, for rocking contactors and a clearance space for a spring contact 10c and 12c, repsecitively. The spring contacts 10c and 12c are attached to a vertical surface of the fulcrum contact by spot welding or the like and are formed at their upper ends to have an inverted V-shaped spring member 10d and 12d, respectively, disposed within the deepest part of the recess to engage the underside of a rocking contactor when assembled thereto. A bifurcated leaf spring wire retainer 14 is inserted into pocket 4e to cooperate with fulcrum contact 10 in retaining a wire conductor in electrical engagement with contact 10 as will be more fully described hereinafter. Similarly, a bifurcated leaf spring contact 16 is inserted into a pocket in the opposite side of base 4 which corresponds to pocket 4e to cooperate with fulcrum contact 12 in the same manner.
The opposite end walls of base 4 have upwardly opening slots 4f and 4g formed therein (only slot 4f is visible in FIG. 6). These slots receive stationary contact members 18 and 20, respectively. Contact 20 is formed as a mirror image of contact 18. The stationary contacts comprise main body portions which have a first formed over projection 18a, 20a extending at substantially right angles to the main body portion. A second formed over projection 18b, 20b, extends at an acute angle from the main body portion. It will be observed that the bend forming projections 18b, 20b is located substantially higher on the main body portion than the bend forming projections 18a, 20a. Each stationary contact member also includes an upstanding pointed barb 18c, 20c disposed between the formed over projections of the respective stationary contact members. These contact members 18 and 20 are inserted into slots 4f and 4g, respectively, from the upper side of base 4 such that the main body portion of each contact is disposed within the slot and the projections extend toward each other within the compartments 6 and 8. The upper end walls of base 4 have recesses 4h and 4j adjacent compartment 8 to receive the projections 18b, 20b, respectively, as the latter extended toward each other into the compartment 8. The right angle projections 18a, 20a of the respective stationary contact members extend toward each other in compartment 6, and lie flat against the floor of that compartment. As seen in FIG. 5, barb 18c, not visible in FIG. 5, 20c extends above the upper surface of base 4 to pierce the upper wall of cover 2, thereby anchoring the upper ends of stationary contact members 18, 20 in position when the cover 2 is assembled to base 4.
A rectangular pocket 4k is formed in the lower portion of base 4 adjacent pocket 4e as seen in FIG. 6. Pocket 4k communicates with groove 4g, not shown in FIG. 6, in the end wall of base 4 and stationary contact member 20 extends through slot 4g into pocket 4k. A leaf spring wire retainer 22 similar to retainers 14 and 16, but not bifurcated, is inserted into pocket 4k to cooperate with the main body portion of stationary contact 20 for retaining a wire conductor inserted through an opening in the bottom of base 4 against the main body portion of stationary contact 20. Base 4 is provided with a corresponding pocket 4m (FIG. 4) on the opposite side thereof which communicates with groove 4f. Stationary contact member 18 extends through groove 4f into the pocket 4m and cooperates with a leaf spring wire retainer 24 which is inserted into the pocket 4m similarly to retainer 22.
A pair of wing shaped rocking contactors 28 and 30 are disposed on fulcrum contacts 10 and 12, respectively. The contactors have notches 28a, 30a formed in opposite lateral edges of the central portions thereof to locate the contactors within the recessed portions of the upper edges of the respective fulcrum contacts 10 and 12. The central web of the contactors between the notches 28a, 30a, respectively, rest upon the pivot surface 10b, 12b, respectively, of the fulcrum contacts to pivot about that surface. The apex of spring contacts 10d, 12d abuts the under surface of contactors 28, 30, respectively, when the contactors are positioned on the fulcrum contacts to enhance the commutation of current from the fulcrum contact to the rocking contactor. The outer ends of each rocking contactor 28 and 30 are formed angularly upward at a shallow angle. When so assembled to the fulcrum contacts, the contactor 30 is disposed above the stationary contacts 18a, 20a so that the opposite ends of the contactor can rock about the fulcrum contact 12 downwardly into alternate engagement with contact 18a or contact 20a (FIG. 4) and contactor 28 is disposed below the stationary contacts 18b, 20b so that when the contactor 28 is pivotally rocked about the fulcrum contact 10, the opposite ends thereof engage the under surfaces of stationary contacts 18b, 20b.
The switch assembly is completed by pivotally mounting an actuator assembly within the cover 2 of the insulating housing. A toggle lever actuator 32 has an intermediate ball portion 32a having trunions 32b extending laterally outwardly therefrom. Toggle lever 32 is inserted into a complementary ball socket within an upstanding cylindrical projection 2b formed on the top wall of cover 2. A rubber seal 34 is disposed over the upper portion of ball 32a prior to assembly to prevent the ingress of foreign materials into the switch through the open bushing 2b. The lower end of toggel actuator 32 is provided with a transverse cross bar 32c which has depending cylindrical bosses 32d at the lateral ends thereof. Although not specifically shown, the bosses 32d are provided with blind counterbores open to the bottom of actuator 32 to slidingly receive plungers 36 therein. The plungers 36 are hollow members and helical compression springs 38 are disposed within the plungers and the bores of cylindrical projections 32d to bias the plungers 36 outwardly of the actuator 32. The lower ends of plungers 36 are formed spherically.
When the cover 2 is assembled to the base 4, the lower ends of plungers 36 resiliently engage the upper surfaces of rocking contactors 28 and 30. In a well known manner, as toggle actuator 32 is pivoted about the pivot formed by trunions 32b within the bushing 2b, the plungers 36 traverse the upper surfaces of contactors 28 and 30 to cross from one side of the vertical plane containing fulcrum contacts 10 and 12 to the other, thereby rocking the respective contactors clockwise or counterclockwise into engagement with the respective stationary contacts 18a, 18b, 20a, 20b. The bias of springs 38 through plungers 36 causes the toggle actuator 32 to assume stable positions on either side of the fulcrum contacts 10, 12. As seen in FIGS. 3 and 4, when the toggle actuator 32 is pivotally moved to dispose the plungers 36 to the left of the fulcrum contacts, the left-hand end of contactor 30 engages stationary contact 18a to bridge contacts 18 and 12 while the right-hand end of contactor 28 engages stationary contact 20b to bridge contacts 10 and 20. Although not specifically illustrated, it will be understood that when toggle actuator 32 is pivotally moved to dispose plungers 36 to the right of fulcrum contacts 10 and 12, the right-hand end of contactor 30 will engage stationary contact 20a while the left-hand end of contactor 28 will engage stationary contact 18b, thereby bridging contacts 10 and 18 and contacts 12 and 20. Accordingly, by making the contacts 18a and 18b at one end of the switch compartments 6 and 8 common and making the contacts 20a and 20b at the opposite end of the compartments 6 and 8 common, and locating the contacts 18b, 20b above the rocking contactor 28, a reversing switch function is accomplished internally of the switch without providing cross connect jumpers, either externally or internally.
The stationary and fulcrum contact members 10, 12, 18 and 20 of the switch are provided with serrations in one surface thereof in alignment with wire receiving holes 4p, 4q, 4r and 4s formed in the bottom of base 4. The formation of the serrations is identical for each of the contact members, and will be described only in conjunction with fulcrum contact 10 illustrated in FIGS. 7 and 8. The serrations 10e are formed by stamping a shallow partial cylindrical recess into the surface of contact 10 which is adjacent the end of leaf spring 14. The serrations comprise 3 arcuate tooth-like projections within the recess. The serrations have outwardly directed upper surfaces and angularly disposed lower surfaces to form substantially upwardly directly teeth which permit the insertion of a bared end of a conductor wire C through the hole 4p between contact 10 and leaf spring 14 into the respective pocket 4e of the switch base. Such insertion deflects the leaf spring 14 upwardly in a well known manner. The end of leaf spring 14 is provided with a shallow V-shaped groove to receive the arcuate shape of the bared end of conductor C. Spring 14 urges the conductor C against the surface of the fulcrum contact 10. The force exerted by spring 14 causes the V-shaped groove thereof to bite into the surface of the conductor C and causes the sharp edges of the serrations 10e to bite into the surface of the conductor from the opposite side thereof, thereby restraining the conductor against withdrawal motion. The conductor insertion holes 4p, 4q, 4r and 4s in the bottom of base 4 communicate with pockets 4e, 4g, 4n and 4m, respectively. Each of these holes are formed in a keyhole shape wherein a tool may be inserted into the rectangular extension of the hole to engage the respective leaf spring retainer and move it inwardly to release the wire conductor when it is desired to remove the conductors.
A second set of conductor insertion holes 4t and 4u, are provided adjacent holes 4p and 4r, respectively, for communication with pockets 4e and 4k, respectively. Holes 4t and 4u are slightly smaller than holes 4p and 4r and are in alignment with a leg 14a or 16a of the bifurcated leaf spring retainers 14 and 16, respectively. These holes 4t and 4u provide press-in wire terminations for connecting an auxiliary device such as a lamp or the like to the source of power through the common contacts provided by contacts 10 and 12, respectively.
The switch as shown in these drawings may be connected to a source of A.C. input power by connecting power conductors to terminals 10 and 12 through holes 4p and 4r, respectively. Holes 4s and 4q are utilized to connect conductors from a load to be controlled by the switch to the output stationary contacts 18 and 20, respectively. The operation of the switch as aforedescribed through the particular contact configurations controls the direction of the current from the contacts 18, 20 to the load.
While the switch of this invention has been described herein in a particular preferred embodiment, it is to be understood that it is susceptible of various modifications without departing from the scope of the appended claims. | A double pole, double throw rocking contactor switch is operable as a reversing switch by particularly configured stationary contacts at the corresponding ends of the respective poles. Stationary contacts are formed electrically common out of a single member having the stationary contact of one pole formed to be disposed below the rocking contactor and the stationary contact of the other pole formed to be disposed above its respective contactor. Accordingly, one contactor engages the upper surface of a stationary contact while the other end of the other contactor engages the under surface of the opposite stationary contact for a given stable position of the actuator, thereby causing the respective contactors to engage stationary contacts at respective opposite ends of the contactors, accomplishing the reversing function internally of the switch without special cross connect conductors, thereby permitting press-in wire terminations to be utilized. The stationary contacts are provided with serrations which cooperate with the leaf spring wire retainers to provide improved press-in wire terminations. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Application No. PCT/CN2008/072920, filed on Nov. 4, 2008, which claims priority to Chinese Patent Application No. 200710124503.X, filed on Nov. 12, 2007, both of which are hereby incorporated by reference in their entireties.
FIELD OF THE INVENTION
[0002] The present invention relates to information technologies, and in particular, to a fixed codebook search method and a searcher.
BACKGROUND OF THE INVENTION
[0003] In the voice coding field, the voice coder based on the Code Excited Linear Prediction (CELP) model is the most widely applicable. As against other voice coders such as a waveform coder and a parameter coder, the CELP-based voice coder accomplishes high voice quality in the case of very low code rates, and still shows excellent performance in the case of high code rates. The CELP-based voice coder uses codebook as an excitation source, and is characterized by low rates, high quality of synthesized voice, high resistance to noise, and high performance of multiple audio transfer operations. The adaptive codebooks and fixed codebooks serving as excitation signals play a very important role in the CELP coder. The function of an adaptive filter is to remove the Long Range Dependence (LRD) from the residual voice signals. After the LRD is removed, the residual voice signals are similar to white noise (quasi-white noise), which is not suitable for precise quantization. Currently, the target signals of fixed codebooks are generally quantized effectively through (1) random codebook method; (2) regular pulse method; (3) auto-correlation algorithm; (4) transform domain algorithm; or (5) algebraic codebook method. These methods have their own characteristics, and fully use the features of fixed codebooks to quantize the signals, but have their defects in terms of quality of voice synthesis, quantity of occupied bits, and complexity of computation. The method widely applied at present is the algebraic codebook method, which has many merits unavailable from other methods. The algebraic codebook method cares about the pulse position of a fixed codebook for the target signal and regards the pulse amplitude as 1 by default. In this way, massive multiplication computation is converted into addition and subtraction computation, and the computation complexity is reduced drastically. Moreover, only the symbol and position of the pulse need to be quantized; the bits required for quantization are reduced; and high voice quality is ensured. However, at the time of searching for the best position of the pulse, a huge computation load is involved in the full search, and real-time search is impossible when there are many pulses. Therefore, a suboptimal search algorithm is required. The quality of the finally synthesized voice depends on the quality of the suboptimal search algorithm directly. Therefore, the search algorithm is vital to calculating the codebook.
[0004] A fixed codebook search method in the prior art includes the following steps:
[0005] (1) Obtain the initial codebook for pulse search.
[0006] (2) The fixed codebook searcher determines the pulse group (supposing that the group includes n pulses), and the pulse group includes at least one initial codebook pulse.
[0007] (3) Select m tracks among several tracks randomly, replace the positions of the pulses in the pulse group selected above with other positions in the m tracks, and calculate the value of the cost function Qk.
[0008] (4) Select tracks randomly for several times, and substitute the pulse group position that increases the Qk value maximally in the selected tracks for the positions of the corresponding pulses in the initial codebook.
[0009] (5) After the pulses in a pulse group are replaced, fix the pulse position of this pulse group, and substitute the pulses on other tracks for the remaining pulses in the initial codebook through step (3) and step (4).
[0010] (6) This process can be repeated.
[0011] The foregoing search method in the prior art involves very low complexity of computation, allows for the correlation between pulses, and provides high performance. However, the count of cyclic searches is fixed, which leads to a low computation efficiency of searching.
[0012] Another fixed codebook search method is provided in the prior art. This method has the following features: (1) providing similar performance as the standard method in the case of a small search count; and (2) being applicable to coders of any ACELP fixed codebook structure, and imposing no special requirements on the pulse position and the track structure. This search method includes: (a) calculating the absolute value of the likelihood function of the pulse position, to obtain the information about the position where a pulse may exist; (b) obtaining a codebook vector temporarily as a initial codebook; and (c) replacing a pulse in the initial codebook, and calculating the cost function Qk; (d) judging whether the Qk value of the codebook increases after the replacement; (e) if the Qk value increases, using the new pulse to replace the old pulse from the initial codebook to obtain a new codebook; and (f) if the Qk value decreases, still using the existing codebook.
[0013] This search method is also characterized by a fixed count of cyclic searches, and also provides a low efficiency of computation.
SUMMARY OF THE INVENTION
[0014] An efficient fixed codebook search method and a fixed codebook searcher are provided in various embodiments of the present invention to reduce the search times and to improve the search efficiency.
[0015] A fixed codebook search method provided in an embodiment of the present invention includes: initializing a counter; searching for pulses and calculating the value of a cost function Qk; initializing the counter to an initial value if the value of Qk increases; and increasing the value of the counter if the value of Qk does not increase; and ending the whole search process when the value of the counter is greater than a threshold value.
[0016] Another fixed codebook search method provided in an embodiment of the present invention includes: setting an initial state flag; searching for pulses and calculating the value of a cost function Qk; modifying the state flag to a non-initial state if the value of Qk increases; and ending the whole search process if the state flag indicates the initial state.
[0017] A fixed codebook searcher provided in an embodiment of the present invention includes: a pulse searching unit, configured to search for pulses; a counter, configured to initialize the counter to an initial value if the value of Qk increases, and increase the value of the counter if the value of Qk does not increase; and a judging unit, configured to judge whether the value of the counter is greater than a threshold value.
[0018] The pulse searching unit ends the whole search process if the judging unit determines that the value of the counter is greater than the threshold value.
[0019] Another fixed codebook searcher provided in an embodiment of the present invention includes: a pulse searching unit, configured to search for pulses; an identifying unit, configured to set an initial state flag and update the state flag to a non-initial state when the Qk value increases; and a judging unit, configured to judge whether the identifying unit indicates the initial state.
[0020] The pulse searching unit ends the whole search process if the judging unit determines that the identifying unit indicates the initial state.
[0021] In the technical solution under the present invention, the counter or the identifying unit records the count of searches in which Qk increases or does not increase. Therefore, the search iteration stops when the preset conditions are fulfilled, thus reducing the search count and improving the search efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a flowchart of a fixed codebook search method in the prior art;
[0023] FIG. 2 is a flowchart of a fixed codebook search method according to embodiment One of the present invention;
[0024] FIG. 3 is a flowchart of a fixed codebook search method according to embodiment Two of the present invention;
[0025] FIG. 4 is a flowchart of a fixed codebook search method according to embodiment Three of the present invention;
[0026] FIG. 5 is a flowchart of a fixed codebook search method according to embodiment Four of the present invention;
[0027] FIG. 6 is a flowchart of a fixed codebook search method according to embodiment Five of the present invention;
[0028] FIG. 7 shows a structure of a fixed codebook searcher according to embodiment Six of the present invention; and
[0029] FIG. 8 shows a structure of a fixed codebook searcher according to embodiment Seven of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Embodiment One
[0030] As shown in FIG. 2 , the fixed codebook search method in this embodiment includes the following steps:
[0031] A1. Obtain the initial codebook, and set the external iteration count “n”.
[0032] For ease of understanding, assume that only one pulse exists on each track, and the pulses are: P0, P1, P2, and P3. Assume that the initial codebook is {i0,i1,i2,i3}={20,33,42,7}. The enclosed numerals indicate the pulse position. Table 1 shows the codebook structure:
[0000]
TABLE 1
Codebook structure
Track
(Tx)
Pulse
Positions
1 (T0)
P0
0, 4, 8, 12, 16, 20, 24, 28, 32 36, 40, 44, 48, 52, 56, 60
2 (T1)
P1
1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61
3 (T2)
P2
2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50, 54, 58, 62
4 (T3)
P3
3, 7, 11, 15, 19, 23, 27, 31, 35, 39, 43, 47, 51, 55, 59, 63
[0033] This embodiment does not limit the method of obtaining the initial codebook. In one embodiment, the initial codebook may be obtained through the “maximum likelihood function of pulse position”.
[0034] A2. Initialize the counter to 0 or −1, or another fixed value. The counter is used to record the count of continuous searches when pulse replacements don't happen. The pulse replacement is: When the Qk value increases, the original pulse combination is replaced with the pulse combination that makes the Qk value increase.
[0035] A3. Search for pulses and calculate the Qk value. Specifically, determine a pulse combination, replace the pulses with the pulse combination on the corresponding track, and calculate the corresponding Qk value. This embodiment does not limit the pulse search method. For example, the pulses may be searched out in the following way:
[0036] Taking the global pulse replacement as an example, the pulse search method is as follows:
[0037] Keep the i1, i2, i3 positions in the initial codebook unchanged; replace the initial value 20 of i0 with value of other position from track T0{0, 4, 8, 12, 16, 24, 28, 32 36, 40, 44, 48, 52, 56, 60} one by one, to obtain new codebook {0,33,42,7}, {4,33,42,7}, . . . {60,33,42,7}; and calculate the cost of the new codebook Qk. The process of pulse search of different pulse positions on the selected track is an internal iteration search.
[0038] A4. Judge the Qk value. Judge whether the Qk value increases. If the Qk value increases, proceed to step A5; otherwise, go to step A6.
[0039] A5. Replace the original pulses with the pulses that make the Qk value increase to obtain a new codebook, and reset the counter to the initial value.
[0040] If the new Qk value is greater than the Qk value of the initial codebook, replace the initial codebook with the new codebook, and use the new codebook as an initial codebook. Assume that the Qk corresponding to {4,33,42,7} is the maximum Qk in the replacement process described above. Store the Qk value “Y0” and the corresponding new codebook {4,33,42,7}.
[0041] A6. Increase the counter value “cnt”. Specifically, the counter value “cnt” may be increased by 1.
[0042] A7. Judge whether the internal iteration search is ended. If the internal iteration search is not ended, return to step A3; if the internal iteration search is ended, proceed to step A8.
[0043] A8. Judge whether the counter value is greater than the threshold value. If the counter value is greater than the threshold value, proceed to step A9; if the counter value is not greater than the threshold value, continue the search process. If the external iteration search is not ended, return to step A2. Search the next track, that is, repeat steps A2, A3, A4, and A5 until all the four tracks T0-T3 are searched completely, whereupon the whole process is ended. Selecting different tracks for searching, as described above, is called “external iteration search”. The foregoing threshold value may be set as required. If the internal iteration count is a, the threshold value may be a multiple of a, or a−1, or a+1, and so on.
[0044] A9. End the whole search process.
[0045] Alternatively, the counter may be initialized before the external iteration search.
[0046] If the counter value “cnt” exceeds the threshold value “thr”, it indicates that no pulse replacement occurs within the threshold count, that is, no better pulse combination is found. In this case, it is deemed that the best pulse has been found, and the whole search process is ended.
Embodiment Two
[0047] Another fixed codebook search method embodiment is provided. As shown in FIG. 3 , this embodiment differs from the first embodiment in that: two internal loops (for example, internal loop 1 and internal loop 2 ) are nested in an external loop. Multiple internal loops may be nested. The specific process of this embodiment are as follows:
[0048] B1. Obtain the initial codebook, and set the external iteration count “n”.
[0049] B2. Initialize the counter value “cnt”.
[0050] The counter may be initialized before the external iteration search, or before the internal iteration search.
[0051] B3. Search for pulses in the internal loop 1 , and calculate Qk value. Replace the pulses with a new pulse combination on the corresponding track, and calculate the corresponding Qk value.
[0052] B4. Judge the Qk value. Judge whether the Qk value increases. If the Qk value increases, proceed to step B5; otherwise, go to step B6.
[0053] B5. Replace the original pulses with the pulses that make the Qk value increase to obtain a new codebook, and initialize the counter “cnt”.
[0054] B6. Increase the counter value “cnt”. Specifically, the counter value “cnt” may be increased by 1.
[0055] B7. Judge whether the internal loop 1 search is ended. If the internal loop 1 search is not ended, return to step B3; if the internal loop 1 is ended, proceed to step B8.
[0056] B8. Search for pulses in the internal loop 2 , and calculate the corresponding Qk value. Replace the pulses with a new pulse combination on the corresponding track, and calculate the Qk value.
[0057] B9. Judge the Qk value. Judge whether the Qk value increases. If the Qk increases, proceed to step B10; otherwise, go to step B11.
[0058] B10. Replace the original pulses with the pulses that make the Qk value increase to obtain a new codebook, and reset the counter to the initial value.
[0059] B11. Increase the counter value “cnt”. Specifically, the counter value “cnt” may be increased by 1.
[0060] B12. Judge whether the internal loop 2 search is ended. If the internal loop 2 search is not ended, return to step B8; if the internal loop 2 search is ended, proceed to step B13.
[0061] B13. Judge whether the counter value “cnt” is greater than the threshold value. If the counter value “cnt” is greater than the threshold value, proceed to step B14; otherwise, continue the search process. If the external loop is not ended, return to step B2.
[0062] B14. End the whole search process.
Embodiment Three
[0063] Another fixed codebook search method is provided in this embodiment. As shown in FIG. 4 , this embodiment differs from the first embodiment in that: a judgment is made about whether the internal loop is ended after a judgment is made about whether the value of the counter “cnt” is greater than the threshold value.
[0064] The specific steps of this embodiment are as follows:
[0065] C1. Obtain the initial codebook, and set the external loop count “n”.
[0066] C2. Initialize the counter “cnt”.
[0067] C3. Search for pulses, and calculate the Qk value. Determine a pulse combination, replace the pulses with the pulse combination on the corresponding track, and calculate the Qk value.
[0068] C4. Judge the Qk value. Judge whether the Qk value increases. If the Qk value increases, proceed to step C5; otherwise, go to step C6.
[0069] C5. Replace the original pulses with the pulses that make the Qk value increase to obtain a new codebook, and reset the counter to the initial value.
[0070] C6. Increase the counter “cnt”. Specifically, the counter “cnt” may be increased by 1.
[0071] C7. Judge whether the value of the counter “cnt” is greater than the threshold value. If the value of the counter “cnt” is greater than the threshold value, go to step C9; otherwise, proceed to step C8.
[0072] C8. Judge whether the internal iteration search is ended. If the internal iteration search is not ended, return to step C3; if the internal iteration search is ended, proceed to step C9.
[0073] C9. Judge whether the external iteration search is ended. If the external iteration search is not ended, return to step C2; if the external iteration search is ended, proceed to step C10.
[0074] C10. End the whole search process.
Embodiment Four
[0075] Another fixed codebook search method is provided in this embodiment. As shown in FIG. 5 , this embodiment differs from the third embodiment in that: Two internal loops (namely, internal loop 1 and internal loop 2 ) are nested in an external loop; and a judgment is made about whether the value of the counter “cnt” is greater than the threshold value before end of each internal loop. Multiple internal loops may be nested. Optionally, a judgment is made about whether the value of the counter “cnt” is greater than the threshold value after end of the internal loop.
[0076] The specific steps of this embodiment are as follows:
[0077] D1. Determine the initial codebook, and set the external iteration count “n”.
[0078] D2. Initialize the counter value “cnt”.
[0079] D3. Search for pulses in the internal loop 1 , and calculate the Qk value. Replace the pulses with a new pulse combination on the corresponding track, and calculate the Qk value.
[0080] D4. Judge the Qk value. Judge whether the Qk value increases. If the Qk value increases, proceed to step D5; otherwise, go to step D6.
[0081] D5. Replace the original pulses with the pulses that make the Qk value increase to obtain a new codebook, and initialize the counter “cnt”.
[0082] D6. Increase the counter value “cnt”. Specifically, the counter valuw “cnt” may be increased by 1.
[0083] D7. Judge whether the value of the counter “cnt” is greater than the threshold value. If the value of the counter “cnt” is greater than the threshold value, go to step D17; otherwise, proceed to step D8.
[0084] D8. Judge whether the internal loop 1 is ended. If the internal loop 1 is not ended, return to step D3; if the internal loop 1 is ended, proceed to step D9.
[0085] D9. Search for pulses in the internal loop 2 , and calculate the Qk value. Replace the pulses with the new pulse combination on the corresponding track, and calculate the Qk value.
[0086] D10. Judge the Qk value. Judge whether the Qk value increases. If the Qk value increases, proceed to step D11; otherwise, go to step D12.
[0087] D11. Replace the original pulses with the pulses that make the Qk value increase to obtain a new codebook, and reset the counter “cnt” to 0.
[0088] D12. Increase the counter value “cnt”. Specifically, the counter value “cnt” may be increased by 1.
[0089] D13. Judge whether the value of the counter “cnt” is greater than the threshold value. If the value of the counter “cnt” is greater than the threshold value, proceed to step D13; otherwise, proceed to step D14.
[0090] D14. Judge whether the internal loop 2 is ended. If the internal loop 2 is not ended, return to step D9; if the internal loop 2 is ended, proceed to step D15.
[0091] D15. Judge whether the value of the counter “cnt” is greater than the threshold value. If the value of the counter “cnt” is greater than the threshold value, go to step D17; otherwise, proceed to step D16.
[0092] D16. Judge whether the external iteration is ended. If the external iteration is not ended, return to step D2; if the external iteration is ended, proceed to step D17.
[0093] D17. End the whole search process.
Embodiment Five
[0094] Another fixed codebook search method is provided in this embodiment. As shown in FIG. 6 , a flag is set to indicate whether a better pulse combination appears in a loop; if a better pulse combination appears, the flag is set to 0; otherwise, the flag value is still −1. Before end of a loop, a judgment is made about whether the flag value is 0; if the flag value is 0, it indicates that a better pulse combination appears in a cyclic replacement process, and the flag value is reset to −1 and a new replacement loop begins. The foregoing process is repeated.
[0095] The specific steps of this embodiment are as follows:
[0096] E1. Determine the initial codebook, and set the external iteration count “n”.
[0097] E2. Initialize the state flag. Set an initial state value, such as −1, 0, or 1.
[0098] E3. Search for pulses in the internal iteration, and calculate the Qk value. Replace the pulse with a new pulse combination on the corresponding track, and calculate the Qk value.
[0099] E4. Judge the Qk value. Judge whether the Qk value increases. If the Qk value increases, proceed to step E5.
[0100] E5. Replace the pulse with the pulse combination that makes the Qk value increase to obtain a new codebook. Modify the state flag to a non-initial state which is different from the initial state value.
[0101] E6. Judge whether the internal iteration is ended. If the internal iteration is not ended, return to step E3; if the internal iteration is ended, proceed to step E7.
[0102] E7. Judge whether the state flag indicates the initial state. If the state flag does not indicate the initial state, proceed to step E8; and, if the state flag indicates the initial state, go to step E9.
[0103] E8. Judge whether the external iteration is ended. If the external iteration is ended, return to step E3.
[0104] E9. End the whole search process.
Embodiment Six
[0105] A fixed codebook searcher is provided in this embodiment. As shown in FIG. 7 , the fixed codebook searcher includes: a pulse searching unit, configured to search for pulses; a counter, configured to be initialized if the value of Qk increases, and increase the value of the counter if the value of Qk does not increase; and a judging unit, configured to end the whole search process when the value of the counter is greater than a threshold value.
Embodiment Seven
[0106] Another fixed codebook searcher is provided in this embodiment. As shown in FIG. 8 , the fixed codebook searcher includes: a pulse searching unit, configured to search for pulses; an identifying unit, configured to identify the initial state, and set the state flag to a non-initial state when the Qk value increases; and a judging unit, configured to judge whether the identifying unit indicates the initial state, and end the whole search process if determining that the identifying unit indicates the initial state.
[0107] Through the foregoing method or apparatus, the counter or the identifying unit records the count of searches in which Qk increases or does not increase. Therefore, the search iteration stops when the preset conditions are fulfilled, thus reducing the search count and improving the search efficiency.
[0108] Detailed above are a fixed codebook search method and a fixed codebook searcher under the present invention. Although the invention is described through some exemplary embodiments, the invention is not limited to such embodiments. It is apparent that those skilled in the art can make modifications and variations to the invention without departing from the spirit and scope of the invention. The invention is intended to cover the modifications and variations provided that they fall in the scope of protection defined by the following claims or their equivalents. | A fixed codebook search method includes: initializing a counter; searching for pulses and calculating the value of a cost function Qk; initializing the counter if the Qk value increases; increasing the value of the counter if the Qk value does not increase; judging whether the value of the counter is greater than the threshold value; continuing the search process if the value of the counter is not greater than the threshold value; and ending the whole search process if the value of the counter is greater than the threshold value. The present invention reduces the search count and improves the search efficiency. | 6 |
FIELD OF THE INVENTION
This invention relates to an erroneous erasure preventing member operated by a device within a magnetic tape cassette to prevent signals recorded on the magnetic tape from being erased by mistake.
BACKGROUND OF THE INVENTION
A conventional audio or video tape cassette has an erroneous erasure preventing means on its peripheral wall, which prevents signals recorded on the magnetic tape from being carelessly erased. The means comprises: a recess formed in the peripheral wall of the cassette; and a tongue-shaped member which is formed in the recess in such a manner as to close the recess. Heretofore, in order to prevent signals recorded on the magnetic tape from being carelessly erased with the tape deck or the like, the tongue-shaped member was removed from the recess. When a cassette from which the tongue-shaped member has been removed is loaded in the tape deck, a detecting member of the tape deck goes into the recess, which has been opened by removing the tongue-shaped member, as a result of which an operating button such as an image recording button or a sound recording button is locked so that signals may not be recorded on the magnetic tape.
In such a system, in order to prevent signals recorded on the magnetic tape from being erased by mistake, it is necessary to remove the tongue-shaped member. When it is subsequently desired to record signals on the magnetic tape of the cassette from which the tongue-shaped member has been removed, it is necessary to close the recess with a piece of adhesive tape. These operations are considerably troublesome for the operator.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of this invention is to proyide a magnetic tape cassette having an erroneous erasure preventing member with which the recording of signals on the magnetic tape by mistake or the erroneous erasure of signals from the magnetic tape can be readily and positively prevented. A device is provided for operating the erroneous erasure preventing member in association with the operation of the tape deck.
According to the invention, a magnetic tape cassette is provided with an erroneous erasure preventing member for preventing signals recorded on the magnetic tape from being erased by mistake. The erroneous erasure preventing member is provided in the peripheral wall of the cassette and comprises: a space which has an opening in the peripheral wall of the cassette; and an opening and closing member fitted in the space, the opening being opened and closed as the opening and closing member moves according to the space.
Also provided in the invention is a magnetic tape cassette operating device which comprises: a substantially F-shaped release lever which has an engagement portion for engaging an opening and closing member adapted to prevent signals recorded on the magnetic tape from being erased by mistake; and a roller adapted to abut against the peripheral wall of the cassette. The release lever is supported by a pin which is loosely fitted in a hole cut in the release lever. When an operating button on a tape deck is depressed, the engagement portion is pushed to engage the opening and closing member, and the opening and closing member is opened when the magnetic tape cassette is ejected.
The foregoing object of the invention has been achieved by the provision of the magnetic tape cassette having the aforementioned erroneous erasure preventing member, and the magnetic tape cassette operating device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing one example of an erroneous erasure preventing member according to this invention.
FIG. 2 is a sectional view taken along line A--A in FIG. 1.
FIG. 3 is a perspective view of the opening and closing member of FIGS. 1 or 2, and
FIGS. 4 and 5 are explanatory diagrams outlining the magnetic tape cassette operating device which is used in conjunction with the erroneous erasure preventing member.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of the invention, the technical concept of which is applied to a video tape cassette and a video tape recorder, will be described with reference to the accompanying drawings.
In FIGS. 1-3, reference numeral 1 designates the upper cassette half (hereinafter referred to as "the upper half 1" when applicable); and reference numeral 2 designates the lower cassette half (hereinafter referred to as "the lower half 2", when applicable). The cassette has an opening 3 cut in its peripheral wall, and a space 4 which communicates with the opening 3, as shown in FIG. 2. An opening and closing member 5 is fitted in the space 4 in a manner such that it is movable vertically in FIG. 2, with its sliding surfaces 5a and 5b abutted, respectively, against inner walls 4a and 4b of the space 4. The opening and closing member 5 has the aforementioned sliding surfaces 5a and 5b, and upper and lower surfaces 5c and 5d, as shown in FIG. 3. The sliding surface 5a and the lower surface 5d are not joined together, thus forming a slit 7. The member 5 is made of elastic material such as polyurethane, ABS or polyacetal resin. The member 5 is so designed that the sliding surfaces 5a and 5b are biased outwardly (as indicated by the arrows in FIG. 3) and, when the member 5 is in the space 4, the sliding surfaces 5a and 5b are suitably pushed against the inner walls 4a and 4b. A knob 6 is formed integrally on the sliding surface 5b in such a manner as to protrude in the opening 3.
The erroneous erasure preventing member of the video tape cassette is constructed as described above. Therefore, a recording can be prevented from being mistakenly erased merely by pushing down the knob 6 of the opening and closing member 5. Although the method is simple, it can positively protect the record from being erroneously erased. Erasure prevention is accomplished in the conventional manner, i.e., erasure and/or recording will be inhibited if the detection probe on the cassette machine is allowed to project into the aperture when the closing member 5 is in its lower position as shown in FIG. 5, while erasure and/or recording will be permitted if the detection probe is not permitted to project into the aperture due to contacting the closing member 5 in its upper position as shown in FIG. 4. When it is necessary to record new data on the tape the cassette can be made to be ready for recording merely by pushing up the knob 6 to close the opening 3.
A magnetic tape cassette operating device which operates the erroneous erasure preventing member in a video tape recorder will be described with reference to FIGS. 4 and 5.
FIG. 4 is an explanatory diagram showing a release lever 8 of the device, which is engaged with the opening and closing member 5. FIG. 5 is an explanatory diagram showing the member 5 in its set state.
The release lever 8 has an engaging pawl 9 at its upper end, and is urged downwardly by spring 14 coupled to its lower end. The release lever 8 is supported by a supporting member 12 loosely fitted in an elongated hole 10 cut therein and has a roller 11 abutted against the peripheral wall of the cassette.
In ejecting a recorded video tape cassette from the video tape recorder, a set button 13 is pushed before the cassette ejecting operation. In this operation, the upper end of the release lever 8 is pushed by the set button 13, and therefore the engaging pawl 9 of the release lever 8 is engaged with the knob 6 of the opening and closing member 5. The set button 13 is maintained against the release lever 8. Under this condition, the cassette is moved in the direction of the arrow B in FIG. 5 by the cassette ejecting operation. As a result, the opening and closing member 5 is slid downwardly in the space 4 by the release lever 8, i.e., the cassette is set so that the recorded signals cannot be erased by mistake.
When the cassette is initially moved in the direction of the arrow B, the release lever 8 is moved in the same direction as the cassette. However, when the supporting member 12 strikes the lower end of the elongated hole 10, the engaging pawl 9 starts moving the member 5 downwardly. In association with this operation, the abutment position of the roller 11 is moved downwardly. When the member 5 has been moved to its lowest position, the roller 11 leaves the wall of the cassette; i.e., it is released from abutment. At the same time, the engaging pawl 9 is disengaged from the knob 6, so that the engaging pawl 9 is moved to reset the set button 13.
In order to smoothly operate the release lever 8, the distance l between the engaging pawl 9 and the roller 11 should be so determined that when the opening and closing member 5 has been set (moved to the lowest position) the roller 11 is disengaged from the wall of the cassette and the release lever 8 is urged obliquely by the spring 14 as illustrated. Thus, in unloading the cassette, the member 5 is set smoothly.
The provision of the erroneous erasure preventing member and the magnetic tape cassette operating device, which are constructed as described above, eliminate the drawbacks accompanying the conventional cassette wherein the tongue-shaped member must be manually removed, and the troublesome operation in which the opening and closing member 5 must be manually moved. Furthermore, in the present invention when a tape cassette is ejected from the video tape recorder, the opening and closing member 5 is automatically set so that the recording is not erased by mistake. | A magnetic tape cassette system includes an erroneous erasing preventing member which is controlled by an operating device on a cassette deck to prevent erroneous erasing of a tape cassette. The erroneous erasing preventing member includes a space with an opening provided on a peripheral wall of a tape cassette, and an opening and closing member which in a first position prevents erasing of the tape cassette and in a second position closes the opening to the space, thereby allowing the tape cassette to be erased. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of data structure initialization techniques. Specifically, this invention is a method, apparatus, system and computer program product for efficiently invoking a programmed operation at the first active use of a data structure or class object. The programmed operation can be used, without limitation, to initialize the data structure or static variables in the class object.
2. Background
A computer's central processing unit (CPU) is designed to execute computer instructions that perform operations on data-values. These data-values are generally stored in variables in memory and in the CPU's registers. Most general purpose computers have specialized instructions for accessing variables having different lengths. For example, a byte-oriented memory-access mode will access a single byte of memory at any byte addressable address in memory. Other non-byte access-modes are used to access two, four, eight, sixteen byte or other sized variables. Each of the non-byte access-modes requires that the variable be aligned on an even memory address. The computer raises a fault condition (a misaligned memory access fault) if a non-byte access-mode is attempted to an odd byte address. This fault condition causes an exception in the computer system and invokes a trap.
Data structures are used to organize information stored in a computer system. Programmed-routines, in a procedural programming paradigm, access the data structures to perform operations dependent on, and/or to modify the contents of, the data structures. These data structures are initialized after they are allocated. The order in which these data structures are initialized is important especially when the initial state of one data structure depends on the state of another data structure. One skilled in the art will understand that the data structure may be pre-initialized by the allocation process to set data fields within the data structure to some default value (usually zero). This pre-initialization is different from the initialization required to set particular data structure elements to initial non-default values.
Object-oriented programming (OOP) languages encapsulate an object's data (generally contained in the object as a data structure) with associated OOP methods for operating on that object's data. Usually, OOP objects are instantiated in a heap memory area and are based on classes that reference the programmed methods for each OOP object. Instantiated OOP objects are accessed through pointers and contain data (in instance variables) specific to that particular instantiated OOP object. Conceptually, an OOP object contains object-related information (such as the number of instance variables in the object), the instance variables, and addresses of programmed routines (OOP methods) that access and/or manipulate the contents of the instance variables in the object. However, because objects often share programmed routines and object-related information, this shared information is usually extracted into a class. Thus, the instantiated object simply contains its own instance variables and a pointer to its class.
The invention applies to both data structures and OOP objects (such as class objects).
Smalltalk, Java and C++ are examples of OOP languages. Smalltalk was developed in the Learning Research Group at Xerox's Palo Alto Research Center (PARC) in the early 1970s. C++ was developed by Bjarne Stroustrup at the AT&T Bell Laboratories in 1983 as an extension of C. Java is an OOP language with elements from C and C++ and includes highly tuned libraries for the internet environment. It was developed at SUN Microsystems and released in 1995.
Further information about OOP concepts may be found in Not Just Java by Peter van der Linden, © Sun Microsystems Press/Prentice Hall PTR Corp., Upper Saddle River, N.J., (1997), ISBN 0-13-864638-4, pages 136-149 which is incorporated herein by reference.
Some OOP languages (such as the JAVA programming language) allow class variables. These class variables allow each instantiated object to access a common instance variable shared by each instantiated object that depends on the class. The static class variables must be initialized prior to their use by any of the instantiated objects. The Java programming language specification requires static class variables to be initialized at the first active use of the class. Further information about initialization of Java classes may be found in The Java™ Language Specification by Gosling, Joy, and Steele, © Sun Microsystems, Inc., Addison-Wesley, ISBN 0-201-63451-1, pages 223-227 which is incorporated herein by reference.
FIG. 1A illustrates a class object data structure, indicated by general reference character 100, that illustrates a data structure used as an OOP class object. The class object data structure 100 includes a `status` field 101 that contains, among other information, the initialization state of the class object. The class object data structure 100 also includes a `static class variable` field 103 used to store the contents of the static class instance variable. The class object data structure 100 also includes a `class method pointer` field 105 that contains an access mechanism to the class' methods such as an array of pointers to these methods.
FIG. 1B illustrates a prior art `data structure access` process, indicated by general reference character 120, used to initialize a data structure at its first active use. The prior art process 120 initiates at a `start` terminal 121 and continues to a `data structure initialized` decision procedure 123 that checks the `status` field 101 of the data structure to determine whether the data structure has been initialized. If the data structure has not been initialized, the prior art process 120 continues to an `initialize data structure` procedure 125 that performs the initialization and modifies the contents of the `status` field 101 to indicate that the data structure has been initialized. Once the `initialize data structure` procedure 125 completes, or if the `data structure initialized` decision procedure 123 determined that the data structure has already been initialized, the prior art process 120 continues to an `access data structure` procedure 127 that performs an active use of the data structure. The prior art process 120 completes through an `end` terminal 129.
The major disadvantage of this prior art approach is that every access to a data structure element in the data structure requires that the computer check whether the data structure has been initialized. Compiler optimization technology exists to optimize out redundant checks by exploiting the fact that only successful checks reach other checks within a routine. In addition, computationally expensive inter-routine analysis can be used to optimize out redundant checks across routine boundaries assuming that the execution sequence can be determined. However, these compiler optimization techniques are computationally very expensive and as a result are often not used.
FIG. 1C illustrates a prior art `adaptive optimization` process, indicated by general reference character 150, for self modifying the executing program code to optimize access to the data structure elements. Using this method, the compiler generates code to invoke an access check routine instead of computer operations to directly access the data structure element. As each access check is encountered, the call-site used to invoke the access check routine is modified to overwrite the invocation of the access check routine with instructions for directly accessing the data structure element. In addition, the access check routine initializes the data structure the first time the access check routine is called on the data structure.
The optimization process 150 initiates at a `start` terminal 151 and continues to an `invoke access check routine` procedure 153. The `invoke access check routine` procedure 153 occurs from the call site at the point where the program would normally access the data structure element. The access check routine, at a `first data structure access` decision procedure 155, then evaluates the `status` field 101 to determine whether the class object data structure 100 has been initialized. If the data structure has not been initialized, the access check routine performs the required initialization at an `initialize data structure` procedure 157. Next, the optimization process 150 continues to a `patch runtime call site` procedure 159. The `patch runtime call site` procedure 159 modifies the computer instructions at the call site to replace the invocation instructions for the access check routine with instructions that actually access the data structure elements in the class object data structure 100 and thus optimize subsequent processing. Generally the `patch runtime call site` procedure 159 also patches other call sites that access the data structure so that only one invocation of the `invoke access check routine` procedure 153 is needed for each data structure.
However, if the class object data structure 100 has already been initialized (or when the `patch runtime call site` procedure 159 completes) the optimization process 150 continues to an `access data structure` procedure 161 (defined by the inserted instructions) that accesses the desired data structure element. Then the optimization process 150 completes through an `end` terminal 163.
The major disadvantage with this prior art method is that the executable program code is self modifying. This solution is not acceptable in many environments. Self modifying code is also very difficult to debug and maintain.
It would be advantageous to provide a technique for a first active use initialization of data structures that does not self-modify executing code nor require special case compiler optimizations and is more efficient than the prior art techniques. Such an inventive technique would improve the performance of computers that use the technique.
SUMMARY OF THE INVENTION
The present invention is a technique for invoking a programmed operation in response to a first active use of an area of memory.
One aspect of the invention is a method for invoking a programmed operation on a data structure responsive to a first active use of the data structure. The method includes the step of associating a data structure access tag storage with the data structure. The data structure access tag storage initially contains a misaligned memory address related to the data structure. Another step is that of triggering a trap on the first active use of the data structure by attempting to access the data structure using the misaligned memory address with an aligned memory access-mode. The invention also includes the step of converting the misaligned memory address within the data structure access tag storage to a aligned memory address. Thus, subsequent attempts to access the data structure using the aligned memory access-mode and contents of the data structure access tag storage will succeed without triggering the trap.
Another aspect of the invention discloses a system for invoking a programmed operation on a data structure responsive to a first active use of the data structure. The invention includes an association mechanism that is configured to associate a data structure access tag storage with the data structure. The data structure access tag storage initially contains a misaligned memory address related to the data structure. The invention also includes a misaligned memory access error mechanism that is configured to trigger a trap on the first active use of the data structure. The first active use of the data structure is by an attempt to access the data structure using a aligned memory access-mode with the misaligned memory address associated with the data structure by the association mechanism. Another element of the invention is an address conversion mechanism that is configured to convert the misaligned memory address within the data structure access tag storage to an aligned memory address. This mechanism is responsive to the misaligned memory access error mechanism. Thus, subsequent attempts to access the data structure using the aligned memory access-mode and contents of the data structure access tag storage will succeed without triggering the trap.
Yet another aspect of the invention is an apparatus for invoking a programmed operation on a data structure responsive to a first active use of the data structure. The apparatus includes an association mechanism configured to associate a data structure access tag storage with the data structure. The data structure access tag storage initially contains a misaligned memory address related to the data structure. The invention also includes a misaligned memory access error mechanism that is configured to trigger a trap on the first active use of the data structure. This mechanism is triggered by an attempt to access the data structure using a aligned memory access-mode with the misaligned memory address associated with the data structure by the association mechanism. Still another element of the invention is an address conversion mechanism that is configured to convert the misaligned memory address within the data structure access tag storage to an aligned memory address. This mechanism is responsive to the misaligned memory access error mechanism. Thus, subsequent attempts to access the data structure using the aligned memory access-mode and contents of the data structure access tag storage will succeed without triggering the trap.
Yet a further aspect of the invention is a computer program product embodied on a computer usable storage medium for invoking a programmed operation on a data structure responsive to a first active use of the data structure. When executed on a computer, the computer readable code causes a computer to effect an association mechanism, a misaligned memory access error mechanism and an address conversion mechanism. Each of these mechanisms having the same functions as the corresponding mechanisms for the previously described apparatus.
An additional aspect of the invention is a computer controlled method for invoking a programmed operation in response to an initial access of a data structure element that is contained within a data structure. The method includes the step of aligning the data structure element on an even memory address. The data structure element is located at an even offset within the data structure such that the data structure element can be accessed using a non-byte access-mode. The method also associates a data structure access tag storage with the data structure. The data structure access tag storage initially contains an odd data structure memory address that is related to the data structure. Another step in the method is that of triggering a trap on the initial access of the data structure element. The trap is triggered by attempting an access of the data structure element using the non-byte access-mode with the odd data structure memory address and the even offset. The method also converts the odd data structure memory address within the data structure access tag storage to an even data structure address. Thus, subsequent attempts to access the data structure element, using the non-byte access-mode with the even data structure address and the even offset, will succeed without triggering the trap. In addition, the method includes the steps of invoking the programmed operation and of accessing the data structure element using the even data structure address.
In yet another aspect of the invention, a computer system is disclosed, including a central processing unit (CPU) and a memory coupled to said CPU, for invoking a programmed operation in response to an initial access of a data structure element contained within a data structure. The system comprises an alignment mechanism that is configured to align the data structure element on an even memory address of the memory. The data structure element is located at an even offset within the data structure such that the data structure element can be accessed from the memory using a non-byte access-mode of said CPU. The system also includes an access tag mechanism that is configured to associate a data structure access tag storage with the data structure. The data structure access tag storage initially contains an odd data structure memory address that is related to the data structure. The system additionally comprises a trigger mechanism that is configured to trigger a trap on the initial access of the data structure element by attempting to access the data structure element in the memory using the non-byte access-mode with the odd data structure memory address and the even offset. An address conversion mechanism is also included within the system. The address conversion mechanism is responsive to the trigger mechanism and is configured to convert the odd data structure memory address within the data structure access tag storage to an even data structure address. Thus, subsequent attempts to access the data structure element using the non-byte access-mode with the even data structure address and the even offset will succeed without triggering the trap. The system also comprises an invocation mechanism that is configured to invoke the programmed operation; and a data access mechanism that is configured to access the data structure element within the memory using the even data structure address.
Another aspect of the invention is an apparatus, having a central processing unit (CPU) and a memory coupled to said CPU, for invoking a programmed operation in response to an initial access of a data structure element contained within a data structure. The apparatus comprises an alignment mechanism that is configured to align the data structure element on an even memory address of the memory. The data structure element is located at an even offset within the data structure such that the data structure element can be accessed from the memory using a non-byte access-mode of said CPU. The apparatus also includes an access tag mechanism that is configured to associate a data structure access tag storage with the data structure. The data structure access tag storage initially contains an odd data structure memory address that is related to the data structure. The apparatus additionally comprises a trigger mechanism that is configured to trigger a trap on the initial access of the data structure element by attempting to access the data structure element in the memory using the non-byte access-mode with the odd data structure memory address and the even offset. An address conversion mechanism is also included within the apparatus. The address conversion mechanism is responsive to the trigger mechanism and is configured to convert the odd data structure memory address within the data structure access tag storage to an even data structure address. Thus, subsequent attempts to access the data structure element using the non-byte access-mode with the even data structure address and the even offset will succeed without triggering the trap. The apparatus also comprises an invocation mechanism that is configured to invoke the programmed operation; and a data access mechanism that is configured to access the data structure element within the memory using the even data structure address.
Yet a further aspect of the invention is a computer program product embodied on a computer usable storage medium for causing a computer to invoke a programmed operation in response to an initial access of a data structure element contained within a data structure. When executed on a computer, the computer readable code causes a computer to effect an alignment mechanism, an access tag mechanism, a trigger mechanism, an address conversion mechanism, an invocation mechanism, and a data access mechanism. Each of these mechanisms having the same functions as the corresponding mechanisms for the previously described apparatus.
The foregoing and many other aspects of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of preferred embodiments that are illustrated in the various drawing figures.
DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates a prior art class object;
FIG. 1B illustrates a first prior art process used to detect a first active use of a data structure or OOP object;
FIG. 1C illustrates a second prior art process used to detect a first active use of a data structure or OOP object and to optimize subsequent uses;
FIG. 2 illustrates a computer system capable of using the invention in accordance with a preferred embodiment;
FIG. 3 illustrates the operational overview of the invention in accordance with a preferred embodiment;
FIG. 4 illustrates a look-up table used to associate a misaligned memory address with a specific class or data structure in accordance with a preferred embodiment;
FIG. 5 illustrates a detailed class object usage process in accordance with a preferred embodiment;
FIG. 6A illustrates a `locate access tag` process in accordance with a preferred embodiment; and
FIG. 6B illustrates a `convert access tag` process in accordance with a preferred embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
Notations and Nomenclature
The following `notations and nomenclature` are provided to assist in the understanding of the present invention and preferred embodiments thereof.
Call-site--A call site is the procedure used to invoke a programmed routine.
Class--The class is an OOP language's implementation that records information common to a set of objects instantiated from the same class or copied from other objects. One skilled in the art will understand that this data structure may or may not be the same data structure used to represent classes used by the programming language's implementation. In addition, the class itself may be an OOP object.
Data structure--A data structure is an ordered arrangement of storage in memory for variables. An OOP object is a specialized data structure.
Object--An object in the object oriented programming paradigm is an association between programmed methods and the data structures defined by a class and the instantiated storage that represents an OOP object of the class.
Pointer--A pointer is a data value that is used to reference a data structure or an object. One skilled in the art will understand that "pointer" includes, without limitation, a memory address to, or a value used to calculate the address to the information of interest and any functional equivalents including handles and similar constructs.
Programmed method--A programmed method is a programmed routine associated with an OOP object. The programmed method is invoked to cause the OOP object to perform an operation.
Programmed routine--A procedure that is called from a call-site such that when the procedure completes it returns to the next instruction after the call-site. A programmed routine corresponds to a "procedure", "function" or "routine" as these terms are used in the art.
Procedure--A procedure is a self-consistent sequence of steps leading to a desired result. These steps are those requiring physical manipulation of physical quantities. Usually these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. These signals are referred to as bits, values, elements, symbols, characters, terms, numbers, or the like. It will be understood by those skilled in the art that all of these and similar terms are associated with the appropriate physical quantities and are merely convenient labels applied to these quantities.
Operating Environment
Although the subsequent description of the invention is cast within the object oriented paradigm and is directed towards Java class objects, the techniques disclosed are applicable to other programming paradigms and that the description also applies to data structures.
The invention uses a computer. Some of the elements of a computer, as indicated by general reference character 200, configured to support the invention are shown in FIG. 2 wherein a processor 201 is shown, having a central processor unit (CPU) 203, a memory section 205 and an input/output (I/O) section 207. The I/O section 207 is connected to a keyboard 209, a display unit 211, a disk storage unit 213 and a CD-ROM drive unit 215. The CD-ROM drive unit 215 can read a CD-ROM medium 217 that typically contains a program and data 219. The CD-ROM drive unit 215, along with the CD-ROM medium 217, and the disk storage unit 213 comprise a filestorage mechanism. Such a computer system is capable of executing applications that embody the invention. One skilled in the art will understand that the CD-ROM drive unit 215 can be replaced by some other device that allows computer readable code to be read into the computer from some media, or over the network. Such a person will also understand that the invention can be practiced on a computer that does not include a keyboard or display.
The invention provides an efficient mechanism to detect a first active use of a data structure (including an OOP object) and to initialize the data structure just prior to the first active use. The invention operates by causing the first active use of a data structure to cause a misaligned memory access fault that results in a trap. This is accomplished by requiring that the memory access operation be performed using a memory access mode that requires an even memory address and attempting the memory access at an odd memory address. The trap handler converts the memory address to an even memory address, performs the data structure initialization, and causes the computer to re-execute the instruction that caused the trap. This attempt to access the now-initialized data structure will succeed because the memory address been converted.
FIG. 3 illustrates a `class object initialization` process, indicated by general reference character 300, used to initialize a class object in response to the first active use of the class object (the initial access). One skilled in the art will understand that the class object is a data structure. The `class object initialization` process 300 initiates at a `start` terminal 301 and continues to a `load class object` procedure 303. The `load class object` procedure 303 allocates memory for the class object and may pre-initialize the class object. The pre-initialization allows the class object to be used by the program containing the object. The pre-initialization is directed to items such as the size of the class object, method pointers, and an initial access tag. However, no user-specified initialization occurs during pre-initialization.
The access tag is pre-initialized to contain a misaligned memory address such that a memory access using an aligned memory access-mode will fail when using an even offset with the access tag. Generally the misaligned memory address is an odd data structure memory address associated with the class object and the aligned memory access-mode is a non-byte access-mode. One skilled in the art will understand that the odd data structure memory address often points to an odd byte location within the class object. Although the class object may be pre-initialized, the data structure elements used as variables within the class object are not initialized until the program attempts a first active use of any of the data structure elements within the class object. One skilled in the art will understand that every access to the class object uses the access tag so that any access to the class object can be the first active use of the class object.
Eventually an executing program attempts the first active use of the class at an `attempt first active use of class` procedure 305 by attempting to access a static class variable. This procedure uses the class' access tag to attempt an indirect-indexed memory access using a non-byte access-mode to access the static class variable (all active uses of the class utilize this technique to actively use the class so that any active use can be the first attempted active use). Because the access tag is pre-initialized to an odd data structure memory address, the memory access attempt fails (because only a byte access-mode instruction can access memory starting at an odd byte boundary). The computer detects the illegal memory access attempt and triggers a trap. The trap causes the computer to execute a `catch misalignment trap` procedure 307 that detects that the memory access was within a class object that was not initialized. The subsequent description describes the invention with respect to modem computer systems that will trap a misaligned memory access attempt when the memory access mode is non-byte oriented and is addressed to an odd memory address.
The `class object initialization` process 300 then modifies the access tag, at a `convert access tag` procedure 309, so that a subsequent non-byte access-mode memory access using the access tag will succeed without causing the misaligned memory access fault. Generally, this modification consists of converting the access tag to an even address within the class object. Thus, subsequent non-byte access-mode accesses will succeed when using the access tag with an even offset. After the `class object initialization` process 300 converts the access tag, it continues to an `invoke initializer methods` procedure 311 that invokes a programmed operation that performs initialization for static class variables and user-specified initialization operations. These initialization processes access the data structure using the modified access tag. Once the data structure is completely initialized, a `complete first active use of class` procedure 313 causes the trap handler to adjust the return program counter (if required) and execute a trap return to re-execute the `attempt first active use of class` procedure 305. Because the access tag is now even, the `attempt first active use of class` procedure 305 will successfully complete. The `class object initialization` process 300 then complet`end` termian `end` terminal 315.
FIG. 4 illustrates a `look-up` table, indicated by general reference character 400, used by a preferred embodiment to associate the access tag with a class object. The `look-up` table 400 contains a `class pointer and extent` array 401 that can be an array of structures, a two dimensional array, or other storage arrangement known in the art. The `class pointer and extent` array 401 includes a `pointer to class A` field 403 that contains a pointer to the first byte of the "A" class (not shown). The `class pointer and extent` array 401 also includes a `size of class A` field 405 that contains the size of the "A" class. Similarly, a `pointer to class B` field 407 contains the address of a `class B` instance 409 that (as are all the classes) is aligned on an even memory address. A `size of class B` field 411 contains the size of the `class B` instance 409. A `pointer to class C` field 413 contains a pointer to a `class C` instance 415 and a `size of class C` field 417 contains the size of the `class C` instance 415. A `pointer to class D` field 419 contains a pointer to the first byte of the "D" class (not shown). A `size of class D` field 421 contains the size of the "D" data structure.
One skilled in the art will understand that, in a non-OOP environment, the `class pointer and extent` array 401 includes pointers to data structures and the size of the data structures. One skilled in the art will also understand that many mechanisms exist for creating the `class pointer and extent` array 401. These mechanisms include (without limitation) creating the `class pointer and extent` array 401 using a compiler (or assembler) along with a linker, dynamically constructing the `class pointer and extent` array 401 when data structures or classes are allocated from memory and many other similar techniques.
The `class B` instance 409 includes a `class B access tag` field 423 that is used to store the access tag. In this embodiment, the initial content of the access tag field is set, during pre-initialization, to be an odd data structure memory address such as the address of the `class B` instance 409 plus one. During the initialization process, the access tag is modified to point to an even data structure address. Thus, the modified access tag points to an even memory address within the class. One preferred embodiment points the modified access tag to the first instance variable in the class. Another preferred embodiment points the modified access tag to the start of the class. The `class B` instance 409 also includes a `static class variable` field 425 that serves as storage for a class instance variable shared by all the classes' objects. In the Java environment, the `static class variable` field 425 must be initialized at the first active use of the class.
The `class B` instance 409 also includes a `class method access` storage 427. One skilled in the art will understand that the `class method access` storage 427 provides means for instantiated objects of the class to invoke the object's methods. The `class C` instance 415 also includes a `class C access tag` field 429 having the same characteristics as that of the `class B access tag` field 423 but initially containing a value that is the address of the `class C` instance 415 plus one. The `class C` instance 415 also contains a `static class variable` field 431 and a `class method access` storage 433 having similar characteristics as the corresponding fields in the `class B` instance 409.
The `class B access tag` field 423, the `static class variable` field 425, the `class method access` storage 427, the `class C access tag` field 429, the `static class variable` field 431 and the `class method access` storage 433 are all aligned on even memory addresses using one or more alignment mechanisms that are well understood in the art. This alignment can be accomplished by requiring that each static class variable start on an even offset from the start of the class instance and that the class instance also start at an even memory address. Another requirement is that each static class variable be accessed using a non-byte access-mode. Thus, a single byte static class variable is expanded by the compiler to be at least two bytes in length and aligned on an even numbered byte. The `look-up` table 400 provides an access tag mechanism that associates the access tag with the class.
FIG. 5 illustrates a `class object usage` process, indicated by general reference character 500, showing a first active use of the class object followed by a subsequent active use. The `class object usage` process 500 initiates at a `start` terminal 501 and continues to a `load access tag` procedure 503. The `load access tag` procedure 503 retrieves the access tag from the access field in the class (for example the `class B access tag` field 423) and places the access tag value in a form that can be used in an indirect-indexed operation. This generally comprises loading the contents of the class' access tag into a register so that a memory access can be performed at a memory location that is offset from the pointer in the register. Next, an `initial access` procedure 505 attempts to access the data structure element (such as the `static class variable` field 425) as an offset from the address pointed to by the pointer in the register. This access is attempted using a non-byte access-mode. This access attempt triggers the computer to generate a misaligned memory access fault on this initial access because the access tag is an odd address with an even offset and uses a non-byte access-mode memory access. Thus, this attempted access is a trigger mechanism that invokes a trap on the first active use of the class object.
One skilled in the art will understand that the address of the data structure element in the class object can be generated by adding the even offset of the data structure element to the access tag value in the register; that the even offset can be used as an offset from the access tag value contained in the register, or other suitable mechanism that is available using the computer's addressing modes.
The resulting trap process saves the state of the computer (including the register containing the access tag) and invokes a `receive trap` procedure 507 within a trap handler. An `extract address` procedure 509 within the trap handler examines the saved computer state and the instruction that caused the misaligned memory access fault and extracts the odd memory address that caused the fault and determines which register contained the access tag at the time of the trap. Once this address is extracted, an `address in class object` decision procedure 511 determines whether the extracted address is an address within some relevant OOP class object (data structure) using the `look-up` table 400. One skilled in the art will understand how to compare the extracted address with the information within the `class pointer and extent` array 401 to make this determination. If the extracted address is not an address within some relevant OOP class, the `class object usage` process 500 continues to a `normal trap processing` procedure 513 to process the trap using prior art methods as the trap was not related to the first active use of the class.
However, if the address was an address within one of the areas of memory (OOP classes) defined by the `class pointer and extent` array 401, the `address in class object` decision procedure 511 generates a pointer to the class object that contains the address. Then the `class object usage` process 500 continues to a `locate access tag` procedure 515 that uses the corresponding pointer in the `class pointer and extent` array 401 to locate the access tag field associated with the class object as is subsequently described with respect to FIG. 6A.
Next, the `class object usage` process 500 continues to a `convert access tag` procedure 517 that converts the access tag stored in an access tag field (such as the `class B access tag` field 423) so that it points to an even memory address such that a non-byte access-mode memory access made to an even offset from the access tag will access the intended data structure element. The `convert access tag` procedure 517 is subsequently described with respect to FIG. 6B.
After the access tag is converted, the `class object usage` process 500 continues to an `adjust return program counter` procedure 519. The `adjust return program counter` procedure 519 modifies the state saved by the `receive trap` procedure 507 to convert the contents of the register containing the access tag to contain the converted access tag. The `adjust return program counter` procedure 519 also adjusts the program counter to re-execute the attempted memory operation (that invoked the trap) with the converted access tag. Next a `class initialization` procedure 520 initializes the class. One skilled in the art will understand that the `class initialization` procedure 520 is an example of an invocation mechanism used to invoke a programmed operation. One skilled in the art will also understand that the initialization will succeed as the access tag has been converted prior to the execution of the `class initialization` procedure 520. Finally a `trap return` procedure 521 restores the computer state (as modified by the `adjust return program counter` procedure 519) and returns to reexecute the instruction that caused the trap at the `initial access` procedure 505. Because the access tag is no longer odd, the previously attempted memory access successfully accesses the initialized data structure. Next the `class object usage` process 500 continues to an `other processing` procedure 523 that performs other procedures. Eventually, a `subsequent access` procedure 525 attempts another access to one of the data structure elements in the data structure using the converted access tag and the even offset to the data structure element in the class object. Because the converted access tag is even, this operation (the data access mechanism) completes without causing a trap. The `class object usage` process 500 completes through an `end` terminal 527. One skilled in the art will understand that the actual sequence of the previously described step can be modified to achieve similar results.
One preferred embodiment of the invention is used to initialize static class variables within a Java class object. This embodiment uses the invoked programmed operation as an initializing procedure that invokes the Java class initializers.
FIG. 6A illustrates a `locate access tag` process, indicated by general reference character 600, invoked by the `locate access tag` procedure 515 of FIG. 5. The `locate access tag` process 600 initiates at a `start` terminal 601 and continues to a `locate class` procedure 603 that uses the address of the data structure returned by the `address in class object` decision procedure 511 as a pointer to the relevant data structure. Then, a `locate access tag` procedure 605 finds the data structure element that contains the access tag (for example the `class B access tag` field 423) and returns a pointer to the access tag storage so that the access tag can be converted by the `convert access tag` procedure 517 of FIG. 5. Although a preferred embodiment places the access tag as the first data structure element in an OOP object or data structure, one skilled in the art will understand that many techniques exist to associate the access tag with its OOP object or data structure.
FIG. 6B illustrates a `convert access tag` process, indicated by general reference character 650 that is invoked by the `convert access tag` procedure 517 of FIG. 5. The `convert access tag` process 650 effectuates an address conversion mechanism. The `convert access tag` process 650 initiates at a `start` terminal 651 and continues to an `odd class access tag` decision procedure 653 that determines whether the access tag associated with the class has not been changed. If the class's access tag is odd, the `convert access tag` process 650 continues to a `convert class access tag` procedure 655 that converts the access tag stored in an access tag field (such as the `class B access tag` field 423) so that it points to an even memory address. Thus, a non-byte access-mode memory access made to an even offset from the access tag will access the intended data structure element. The `convert access tag` process 650 then continues to a `convert access tag in register` procedure 657 after the `convert class access tag` procedure 655. The `convert access tag in register` procedure 657 is also reached if the `odd class access tag` decision procedure 653 determined that the class' access tag was even. The `convert access tag in register` procedure 657 also converts the access tag that is in the register saved by the `receive trap` procedure 507. Thus, when the trap returns, subsequent accesses to the class using that register will succeed. One skilled in the art will understand that the register that contains the odd access tag is determined by examining the instruction that caused the trap during the `extract address` procedure 509. Finally, the `locate access tag` process 600 completes through an `end` terminal 659.
One preferred embodiment is practiced within the procedural program paradigm. Another preferred embodiment is practiced using classes in the object-oriented programming (OOP) paradigm. In the OOP paradigm, the data structure is included in a class and the data structure element is a static class variable. One skilled in the art will understand that the invention can be used to invoke a programmed operation responsive to the first memory access to an area of memory. One preferred embodiment is used in Java environments to initialize static class variables at the class' first active use as required by the Java programming language specification.
The invention efficiently invokes a programmed operation when a data structure or OOP object is first accessed. In particular the invention provides an efficient mechanism for initializing Java classes at their first active use.
From the foregoing, it will be appreciated that the invention has (without limitation) the following advantages:
1) The runtime check for the first active use of a data structure is transparent to a compiler optimizer.
2) Compiler optimizations of computer instructions used to access the data structure can safely optimize such computer instructions without requiring special optimization cases.
3) Only the first active use of the data structure incurs any overhead. Subsequent active uses do not.
Although the present invention has been described in terms of presently preferred embodiments, one skilled in the art will understand that various modifications and alterations may be made without departing from the scope of the invention. Accordingly, the scope of the invention is not to be limited to the particular invention embodiments discussed herein, but should be defined only by the appended claims and equivalents thereof. | Apparatus, methods, systems and computer program products are disclosed that provide an efficient mechanism for invoking a programmed operation at the first active use of the OOP object or data structure. The programmed operation can be used to initialize an object-oriented programming (OOP) object or data structure. The first active use of the data structure or OOP object is detected because the initial access mechanism is constrained to cause a misaligned memory access fault (trap) by attempting a non-byte access-mode memory access to an odd byte address. As the fault is processed, the access mechanism is converted so that the initial and subsequent non-byte access-mode memory accesses will succeed. In addition, the OOP object or data structure is initialized. Then the initial access attempt is repeated on the just initialized OOP object or data structure using the converted access mechanism. The use of the invention improves the performance of computers by reducing the overhead involved with particular computational operations. | 8 |
RELATED APPLICATIONS
[0001] This is a Continuation-In-Part of U.S. Ser. No. 07/551,622 filed Jul. 11, 1990. The teachings of this application are incorporated herein by reference.
BACKGROUND
[0002] Salmeterol, 4-hydroxy-α 1 -[[6-(4-phenylbutoxy) hexyl]amino]methyl-1,3-benzenedimethanol, is a drug belonging to the general class of beta-adrenergic compounds. The prime action of beta-adrenergic drugs is to stimulate adenyl cyclase, the enzyme which catalyzes the formation of cyclic-3′,5′-adenosine monophosphate (AMP) from adenosine triphosphate (ATP). The cyclic AMP formed mediates the cellular responses. Salmeterol acts selectively on beta 2 -adrenergic receptors to relax smooth muscle tissue, For example, in the bronchial system. Salmeterol is most commonly used to treat bronchial spasms associated with asthma. Its activity is similar to that of albuterol which is the active component in well-known commercial bronchodilators such as Proventil and Ventolin. However, the beneficial effects of salmeterol are longer lasting than those of albuterol. Thus, use of salmeterol is more desirable than use of albuterol.
[0003] The form in which salmeterol is presently used is a racemic mixture. That is, it is a mixture of optical isomers, called enantiomers. Enantiomers are structurally identical compounds which differ only in that one isomer is a mirror image of the other and the mirror images cannot be superimposed. This phenomenon is known as chirality. Most biological molecules exist as enantiomers and exhibit chirality. Although structurally identical, enantiomers can have profoundly different effects in biological systems: one enantiomer may have a specific biological activity while the other enantiomer has no biological activity or may have an entirely different form of biological activity.
SUMMARY OF THE INVENTION
[0004] The present invention relates to a method of treating bronchial disorders, such as asthma, in an individual, by administering to the individual an amount of optically pure R(−) salmeterol which is active in bronchial tissue and is sufficient to reduce bronchial spasms associated with asthma while minimizing side effects associated with salmeterol as it is now given. The method is particularly useful in treating asthma while reducing side effects of salmeterol as it is now given, such as central nervous system stimulatory effects and cardiac arrhythmia. In these applications, it is important to have a composition which is a potent broncho-dilator but does not produce the adverse side effects of many beta-adrenergic drugs. A composition containing the pure R(−) isomer of salmeterol is particularly useful for this application because this isomer exhibits these desired characteristics. The present method provides a safe, effective method for treating asthma while reducing undesirable side effects, such as hypersensitivity, tolerance (tachyphylaxis), tremor, nervousness, shakiness, dizziness and increased appetite, and particularly, cardiac arrhythmia, typically associated with beta-adrenergic drugs. In children, side effects such as excitement, nervousness and hyperkinesia are reduced when the pure isomer is administered. Because R(−) salmeterol can be administered at lower doses than racemic salmeterol, there is also a reduced likelihood of toxicity. For example, an equipotent R(−) salmeterol dose exhibits lower toxicity to the renal and hepatic system as evidenced by less deviation from normal in kidney and liver function tests.
DETAILED DESCRIPTION OF THE INVENTION
[0005] The present invention relies on the broncho-dilation activity of the R(−) enantiomer of salmeterol to provide relief from bronchial disorders, while simultaneously reducing toxicity and other undesirable side effects, such as hypersensitivity, tachyphylaxis, central nervous system stimulatory effects and cardiac disorders, commonly experienced by salmeterol users. In the present method, the optically pure R(−) isomer of salmeterol, which is substantially free of the S(+) enantiomer, is administered alone, or in combination with one or more other drug(s) in adjunctive treatment, to an individual in whom asthma relief (e.g., relief from bronchial spasms, shortness of breath) is desired. The optically pure R(−) isomer of salmeterol as used herein refers to the levorotatory optically pure isomer and to any biologically acceptable salt or ester thereof. The terms “optically pure” or “substantially free of the S(+) enantiomer” as used herein means that the composition contains at least 90% by weight of the R(−) isomer of salmeterol and 10% by weight or less of the S(+) isomer. Optically pure salmeterol is readily obtainable by methods known to those of skill in the art, for example, by synthesis from an optically pure intermediate.
[0006] In the present method, the R(−) isomer of salmeterol is administered to an individual who has asthma. For example, R(−) salmeterol is administered to an individual after onset of asthma to reduce breathing difficulty resulting from asthma. In another embodiment, optically pure R(−) salmeterol is administered prophylactically, that is, before the bronchiospasm begins in an asthma attack, to prevent its occurrence or to reduce the extent to which it occurs.
[0007] In the present method, R(−) salmeterol can be administered by inhalation, by subcutaneous or other injection, orally, intravenously, topically, parenterally, transdermally, rectally or via an implanted reservoir containing the drug. The form in which the drug will be administered (e.g., inhalant, powder, tablet, capsule, solution, emulsion) will depend on the route by which it is administered. The drug also can be administered in sustained-release dosage forms, either orally or topically, e.g. by transdermal delivery from a topically applied patch or similar device. The quantity of the drug to be administered will be determined on an individual basis, and will be based at least in part on consideration of the individual's size, the severity of the symptoms to be treated and the result sought. In general, quantities of optically pure R(−) salmeterol sufficient to reduce the symptoms of asthma will be administered. The actual dosage (quantity administered at a time) and the number of administrations per day will depend on the mode of administration, for example, by inhaler, nebulizer, topical or oral administration. About 25 mcg to about 50 mcg of the optically pure R(−) isomer of salmeterol given by inhalation one or more times per day will be adequate in most individuals to produce the desired bronchodilation effect. For oral administration, e.g., tablet or syrup, a dose of about 1 mg to about 8 mg two to four times daily is administered to produce the desired effect.
[0008] In the method of the present invention, the optically pure R(−) isomer of salmeterol can be administered together with one or more other drug(s). For example, an antiasthmatic drug such as theophylline or terbutaline, or an antihistamine or analgesic such as aspirin, acetaminophen or ibuprofen, can be given with or in close temporal proximity to administration of optically pure, R(−) salmeterol. The two (or more) drugs (i.e., the optically pure active isomer of salmeterol and another drug) can be administered in one composition or as two separate entities. For example, they can be administered in a single capsule, tablet, powder, or liquid, etc. or as individual compounds. The components included in a particular composition, in addition to optically pure salmeterol and another drug or drugs, are determined primarily by the manner in which the composition is to be administered. For example, a composition to be administered in inhalant form can include, in addition to the drug(s), a liquid carrier and/or propellent. A composition to be administered in tablet form can include a filler (e.g., lactose), a binder (e.g., carboxymethyl cellulose, gum arabic, gelatin), an adjuvant, a flavoring agent, a coloring agent and a coating material (e.g., wax or a plasticizer). A composition to be administered in liquid form can include the combination of drugs and, optionally, an emulsifying agent, a flavoring agent and/or a coloring agent.
[0009] In general, according to the method of the present invention, the optically pure R(−) isomer of salmeterol, alone or in combination with another drug(s), is administered to an individual periodically as necessary to reduce symptoms of asthma.
[0010] The present composition and method provide an effective treatment for asthma while minimizing or eliminating tachyphylaxis, hypersensitivity, toxicity and other undesirable side effects associated with salmeterol use as now given. These side effects include central nervous system effects, such as tremor, nervousness, shakiness, dizziness and increased appetite, and cardiac effects, such as cardiac arrhythmia. In children, side effects such as excitement, nervousness and hyperkinesia are reduced when the pure isomer is administered.
[0011] Exemplification
[0012] The invention is further defined by reference to the following procedures describing the pharmacological characterization of the compositions of the present invention and by reference to the following method of administering the compositions of the present invention. It will be apparent to those skilled in the art that many modifications, both to materials and methods, may be practiced without departing from the purpose and interest of this invention.
[0013] Pharmacological Characterization Procedures
Procedure 1
[0014] β-Adrenergic Receptor Phosphorylation by β-Adrenoreceptor Kinase
[0015] Reconstituted β-adrenergic receptor is incubated with β-adrenoreceptor kinase in a buffer containing 20 mM Tris-HCl, pH 7.5, 2 mM EDTA, 20 mM NaCl, 6 mM MgCl 2 , 6 mM sodium phosphate, 0.5 mM ascorbic acid 60 μM [γ 32 P]ATP at 30° C. The incubations also contain varying concentrations of one of the following: buffer (control) (−)-isoproterenol, R(−) salmeterol, S(+) salmeterol or racemic salmeterol. The incubations are stopped by the addition of SDS sample buffer followed by electrophoresis on 10% homogeneous polyacrylamide gels. Stoichiometries of phosphorylation are determined by cutting and counting the dried gel as described in Benovic J. L. et al., J. Biol. Chem. 9026-9032 (1987).
Procedure 2
[0016] Purification of Component Proteins
[0017] The β-adrenergic receptor from hamster lung is purified to >95% homogeneity by sequential affinity chromatography and high performance liquid chromatography as described in Benovic et al., Biochemistry 23, 4510-4518 (1984). The stimulatory guanine nucleotide regulatory protein is purified from membranes derived from bovine cerebral cortex. The membranes, solubilized with 1% cholate, are centrifuged and the resulting supernatant chromatographed on DEAE-Sephacel, Ultrogel AcA34, octyl-Sepharose, and hydroxyapatite, with a final step on DEAE-Sephacel, as adapted from Strittmater et al., Proc. Natl. Acad. Sci. 77, 6344-6348 (1980). The resulting protein should be 50-90% pure by Coomassie Blue staining of polyacrylamide gels. The catalytic moiety of adenylate cyclase is solubilized from bovine caudate with sodium cholate and isolated from the other components of the system by Sepharose 6B chromatography as described in Strittmater et al., supra. β-Adrenoreceptor kinase is purified from bovine cerebral cortex. The tissue is homogenized, and the resulting high speed supernatant fraction is precipitated with 13-26% ammonium sulfate. This material is then chromatographed on Ultrogel AcA34, DEAE-Sephacel, and CM-Fractogel. The preparations used should be 10-20% pure as judged by Coomassie Blue staining of SDS-polyacrylamide gels.
[0018] Assay for Adenylate Cyclase Activity
[0019] The co-reconstitution of the purified proteins is carried out as described in Cerione et al., J. Biol. Chem. 259 9979-9982 (1984). The pelleted proteins are incubated for 15 min. at 37° C. in 30 mM Tris-HCl, pH 7.5 containing 1 mM ATP, 2 μCi of [α- 32 P]ATP 0.14 mM cAMP, 100 mM sucrose, 0.4 mM dithiothreitol, 2.8 mM phosphoenol pyruvate, 5.2 μg/mL pyruvate kinase, 10 μg/ml of myokinase, 5 mM MgCl 2 , and varying concentrations of racemic salmeterol, R(−) salmeterol and S(+) salmeterol (total volume=0.5 mL). The reaction is stopped by the addition of 0.25 mL 2% sodium dodecylsulfate containing 40 mM ATP and 1.4 mM cAMP at pH 7.5. Water (0.5 mL) is added to each reaction tube and the contents placed on a Dowex 50AG WX4 resin. The eluate from the columns plus two successive water washes (1.0 mL) are discarded. The columns are then eluted with 3 mL water and the eluates collected in test tubes. Each fraction is diluted with 0.2 mL of 1.5 M imidazole HCl, pH 7.2. The tubes from each concentration (run in triplicate) are combined and decanted into columns containing 0.6 g neutral alumina that has been previously washed with 0.1 M imidazole HCl, pH 7.5. The eluate is collected in scintillation vials containing 12 mL Aquasol®. After the columns are completely drained, they are washed with an additional 1 mL of 0.1 M imidazole HCl, pH 7.5 which is collected in the same scintillation vials. The concentration of 32 P-cAMP is determined in each sample.
Procedure 3
[0020] β-Selectivity Studies
[0021] Albino, female guinea pigs, weighing 300 to 500 g, are killed by trauma to the head. The tissues are removed, trimmed of excess tissue and suspended in water-jacketed (37-38° C.) 10-ml tissue baths containing a physiologic salt solution of the following composition: 118 mM NaCl, 4.7 mM KCl, 2.5 mM CaCl 2 .2H 2 O, 0.5 mM MgCl 2 .6H 2 O, 1 mM NaH 2 PO 4 .H 2 O, 25 mM NaHCO 3 , and 11 mM glucose. The tissue baths and stock salt solution are aerated with a mixture of oxygen (95%) and carbon dioxide (5%). Mechanical responses are recorded on a polygraph via force displacement transducers.
[0022] Cumulative dose-response effects of the agonists are obtained by increasing the concentrations by a factor of about 3 while the previous dose remains in contact with the tissue. Each concentration is added only after the effects of the previous concentration reach maximum and remain constant. Final maximum responses are taken to be the effects occurring when a 3-fold increase in agonist concentration fails to further elicit a response. The time required to obtain complete dose-response effects varies with the agonist employed. All other compounds are added to the bath in a volume of 0.1 ml and allowed to interact with the tissue for fixed periods of time.
[0023] Isolated Right Atria
[0024] Spontaneous atrial contractions are recorded together with atrial rate which is monitored with tachographs to aid in determining when maximum responses occur after a given concentration of agonist. The amount of tension exerted on each atrium is the maximum needed to obtain a pen deflection of about 0.5 cm/beat at the highest preamplifier sensitivity without recording background noise. Each tissue is allowed to equilibrate for 1 hour prior to addition of any drug, and washings are made at 15-minute intervals during this period. For construction of dose-response curves, the initial rate (beats per minute) is taken as that occurring just prior to beginning cumulative drug addition.
[0025] Isolated Treacheal Strips
[0026] Trachea are cut in spiral fashion, each turn separated by 3 to 4 cartilage segments. Each strip is approximately halved and each half mounted in a tissue bath. Resting tension is adjusted to 5 g and maintained at that level during equilibration and drug incubation periods. Strips are allowed to equilibrate for 2 hours prior to addition of any drug, and washings are made at 15-minute intervals during this period. Relaxation produced by beta receptor agonists is studied after partial contraction with 3×10 −7 M carbachol. As previously determined, this concentration produces a degree of contraction representing approximately 30% of the maximum capable of being produced by this agonist. The contraction reaches maximum in 10 to 15 minutes and remains constant for at least 1 hour. In order to keep drug contact periods constant, cumulative addition of beta receptor agonists is begun 15 minutes after addition of carbachol to the bath.
[0027] Drug Administration by Oral Inhalation
[0028] The metered dose dispenser contains micronized (R) salmeterol in suspension. Each actuation delivers 25 μg of (R) salmeterol from the mouthpiece. Each canister provides about 120 inhalations. The chemical composition of a metered dose is provided below in Table 1.
TABLE 1 Quantity Contained in Each Metered Dose Dispenser Formula 7.5 mL (10.5 g) Canister (R) Salmeterol 3.0 mg Trichloromonofluoromethane 5.16 g Dichlorodifluoromethane 5.16 g Sorbitan Trioleate 0.105 g
[0029] Equivalents
[0030] Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed in the scope of the following claims. | The optically pure R(−) isomer of salmeterol, which is substantially free of the S(+) isomer, is a potent bronchodilator for relieving the symptoms associated with asthma in individuals. A method is disclosed utilizing the optically pure R(−) isomer of salmeterol for treating asthma while minimizing toxicity and other side effects associated with salmeterol. | 0 |
[0001] This application claims benefit of U.S. Provisional Application No. 60/872,514, filed Dec. 4, 2006, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The method and system disclosed relate to the field of mobile communications, and more specifically, a system for and method of distributing traffic information within a network of wireless communication devices.
FIELD OF THE INVENTION
[0003] Wireless communications devices have become ubiquitous recently, with seemingly every individual fitted with a personal digital assistant having wireless communications capability or with a smart telephone. These wireless devices enable their owners to maintain in communication with a vast array of data networks, such as the Internet. Thus, wireless devices serve as portals for receiving and transmitting data between the user of the wireless device and others in the networked world.
[0004] Typically, information exchanged between individuals tends to be voice and data, with data communications including, for example, electronic mail exchange, instant messaging, texting, and browsing the World Wide Web. Despite the growing presence of wireless devices, their use as the source of data gathering and dissemination has not been fully exploited. For example, many users of wireless devices are traveling in cars and thus are aware of various traffic conditions. In addition, some wireless devices have the ability to determine their speed and position through, for example, the Global Positioning System.
[0005] While wireless device users in certain cities have the ability to access certain centralized traffice information, for example, Atlanta, Ga. traffic data at the Georgia Navigator at www.georgia-navigator.com, system such as this do not permit the two-way flow of information. In other words, users of the Georgia Navigator cannot submit traffic data to the Georgia Navigator website. Neither can wireless devices transmit traffic data to each other.
SUMMARY
[0006] A method of distributing traffic information is provided. The method comprises: receiving location information and identification information from a first wireless device; calculating speed of the first wireless device; and transmitting one or more of the speed, location, and identification of the first wireless device to a second wireless device.
[0007] In accordance with a further embodiment, a system for distributing traffic information is provided. The system comprises: a memory; and a processor, coupled to the memory. The processor is operable to: receive location information and identification information from a first wireless device; calculate speed of the first wireless device; and transmit one or more of the speed, location and identification of the first wireless device to a second wireless device.
[0008] In accordance with another embodiment, a method of distributing traffic information is provided. The method comprises: receiving speed and location information from a first wireless device; and transmitting the speed and location of the first wireless device to a second wireless device.
[0009] In accordance with a further embodiment, a system for distributing traffic information is provided. The system comprises: a memory; and a processor, coupled to the memory. The processor is operable to: receive speed and location information from a first wireless device; and transmit the speed and location of the first wireless device to a second wireless device.
[0010] In accordance with another embodiment, a method of distributing traffic information is provided. The method comprises: receiving identification information from a first wireless device; searching for a second wireless device having identification information that matches the identification information received from the first wireless device; receiving one or more of speed information and location information from the second wireless device; and transmitting one or more of the speed information and location information received from the second wireless device to the first wireless device.
[0011] In accordance with a further embodiment, a system for distributing traffic information is provided. The system comprises: a memory; and a processor coupled to the memory. The processor is operable to: receive identification information from a first wireless device; search for a second wireless device that matches the identification information received from the first wireless device; receive one or more of speed information and location information from the second wireless device; and transmit one or more of the speed information and location information received from the second wireless device to the first wireless device.
[0012] In accordance with another embodiment, a method of distributing traffic information is provided. The method comprises: receiving location information from a first wireless device; searching for a second wireless device that matches the location information of the first wireless device; and transmitting one or more of speed information and identification information from the second wireless device to the first wireless device.
[0013] In accordance with a further embodiment, a system for distributing traffic information is provided. The system comprises: a memory; and a processor, coupled to the memory. The processor is operable to: receive location information from a first wireless device; search for a second wireless device that matches the location information of the first wireless device; and transmit one or more of speed information and identification information from the second wireless device to the first wireless device.
[0014] The foregoing summarizes only a few aspects of the invention and is not intended to be reflective of the full scope of the invention as claimed. Additional features and advantages of the invention are set forth in the following description, may be apparent from the description, or may be learned by practicing the invention. Moreover, both the foregoing summary and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate a system consistent with the principles of the invention and, together with the description, serve to explain the principles of the invention.
[0016] FIG. 1 is a diagram of a first wireless communications system operating in a client-server mode consistent with the principles of the present invention.
[0017] FIG. 2 is a diagram of a second wireless communications system operating in a peer-to-peer mode consistent with the principles of the present invention.
[0018] FIG. 3 is a flowchart of a client-server method consistent with the present invention for distributing traffic information.
[0019] FIG. 4 is a flowchart of a peer-to-peer method consistent with the present invention for distributing traffic information.
DESCRIPTION
[0020] The principles of the present invention may be understood with reference to this description. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0021] The principles of the present invention improve upon prior art traffic reporting systems by distributing location and identification among wireless devices. Wireless devices may communicate location and identification information through a central server in a client-server architecture, or wireless devices may communicate location and identification information among themselves using a peer-to-peer architecture. Embodiments of the traffic information distribution system may also implement a hybrid approach with some information transmitted via client-server communications and other information transmitted via peer-to-peer communications. Similarly, speed of a wireless device may be calculated by the wireless device and transmitted to other devices, or the central server or other devices may calculate the speed of the wireless device based on the changing location information transmitted by the wireless device. Those skilled in the art may now appreciate that information in addition to speed, location, and identification may be distributed among wireless devices, and that the information distributed among wireless devices may also be provided to clients external to the wireless communications system.
[0022] FIG. 1 is a diagram of a first wireless communications system 100 operating in a client-server mode consistent with the principles of the present invention. A server 110 may include a processor in communication with a memory device. Methods of the present invention may be stored as instructions in the memory device of server 110 for execution by the processor of server 110 . Server 110 may also include communications interfaces to networks, such as the Internet for example. Server 110 communicates with one or more wireless devices 130 a - c using a communications unit 120 .
[0023] Communications unit 120 may communicate with wireless devices 130 a - c using radio frequency communication and communications systems and protocols, such as, for example, WIFI (e.g., IEEE 802.11a, b, c, g, or n), WiMax (e.g., IEEE 802.16), GSM, GPRS, 3G (e.g., UMTS, CDMA2000, and Wideband CDMA), and 4G systems. Wireless devices 130 a - c may comprise a processor coupled to a memory for storing and executing instructions for implementing embodiments of the present invention. Wireless devices 130 a - c may also include a radio frequency communications interface, coupled to the processor, for communicating with communications unit 120 . Wireless devices 130 a - c may also include a locating device, such as a Global Positioning System (GPS) receiver or may calculate location based on less direct methods such as triangulation of signal strength of multiple communications towers. Wireless devices 130 a - c may be, for example, personal digital assistants (PDA's), smart phones, user devices, computers, or Global Positioning System (GPS) devices.
[0024] In wireless communications system 100 of FIG. 1 , wireless communication devices 130 a - c may periodically transmit location and identification information to server 110 . Location information includes the location of the wireless device. Identification information is information sufficient to uniquely identify the wireless device within a given geographical region, for example, within a particular city or neighborhood within a city. The server 110 may use the location and identification information to calculate a speed of the wireless device. Alternatively, the communications device may calculate and transmit speed information to server 110 . Server 110 sends one or more of the received location, speed, and identification information to at least one other wireless device, so that the other wireless device learns of traffic information. Thus, multiple wireless devices 130 a - c may exchange information regarding traffic information using server 110 .
[0025] FIG. 2 is a diagram of a second wireless communications system 200 operating in a peer-to-peer mode consistent with the principles of the present invention. As in the first system of FIG. 1 , second wireless communications system 200 is utilized to exchange traffic information between multiple wireless devices 130 a - c , without the necessity of a server 110 . Server 110 may be present, for example, to facilitate identification of wireless devices to each other, to centrally monitor, gather, and distribute traffic information from wireless devices 130 a - c to outside systems, such as over the Internet, or to distribute other information to wireless devices 130 a - c . However, second wireless communications system 200 operates on a peer-to-peer basis by communicating information, such as location, identification, or speed, between wireless devices 130 a - c , without the need for a central server. As in wireless communications system 100 , receiving devices, for example wireless device 130 c , may compute speed based on changing location or sending devices may compute and transmit speed.
[0026] In addition, both wireless communications systems 100 and 200 may use server 110 to provide traffic information to other users. Other users may include, for example, commercial business organizations, government entities, or private persons. In addition, server 110 may receive information from outside sources, such as a government traffic control center, and provide the received information to one or more wireless devices 130 a - c . For example, the government traffic control center may track accident information, send that information to server 110 , which may in turn distribute it to one or more wireless devices 130 a - c.
[0027] FIG. 3 is a flowchart of a client-server method consistent with the present invention for distributing traffic information. Traffic information is received from a first wireless device (stage 310 ). The traffic information may include, for example, location and identification information, as previously described. In addition, the traffic information received may include speed information. If speed information is not received, speed is calculated based on, for example, at least the differential value of two receptions of location information from the same wireless device (stage 320 ). The speed information, related to either the location or identification information received from the first wireless communication device may be stored in the server. The traffic information of a specified location or identification may be retrieved from the server and may be transmitted to a second wireless device, where the information may include, for example, one or more of speed, location, and identification information (stage 330 ). The specified location or identification may be assigned by either the first wireless device, the second wireless device, or the server. In this fashion, traffic information may be distributed among wireless devices using client-server methodology.
[0028] While not illustrated, additional stages may be present in the above method. For example, additional information may be received from external information providers, such as government traffic control center's and transmitted to the wireless devices in stage 330 .
[0029] FIG. 4 is a flowchart of a peer-to-peer method consistent with the present invention for distributing traffic information. Traffic information is received by a second wireless device from a first wireless device (stage 410 ). The traffic information may include, for example, location and identification information, as previously described. In addition, the traffic information received may include speed information. If speed information is not received, speed is calculated based on, for example, at least the differential value of two receptions of location information from the same wireless device (stage 420 ). Traffic information is then transmitted by the second wireless device to the first wireless device, where this traffic information may include, for example, location and identification information, as well as speed information (stage 430 ). In this fashion, traffic information may be distributed among wireless devices using peer-to-peer methodology. While not illustrated, the first and second wireless device may transmit traffic information to a server.
[0030] In any embodiments consistent with the principles of the present invention, the server may maintain a relationship table of the wireless device identification information and its location information. In this fashion, the server could introduce a second wireless device that matches the location or identification information specified by a first wireless device to the first wireless device for exchanging traffic information.
[0031] Those skilled in the art will appreciate that all or part of systems and methods consistent with the present invention may be stored on or read from other computer-readable media, such as: secondary storage devices, like hard disks, floppy disks, flash storages, CD, or DVD; a carrier wave received from the Internet; or other forms of computer-readable memory, such as read-only memory (ROM), random-access memory (RAM), or magnetic RAM.
[0032] Furthermore, one skilled in the art will also realize that the processes illustrated in this description may be implemented in a variety of ways and include multiple other modules, programs, applications, scripts, processes, threads, or code sections that all functionally interrelate with each other to accomplish the individual tasks described above for each module, script, and daemon. For example, it is contemplated that these programs modules may be implemented using commercially available software tools, using custom object-oriented, using applets written in the Java programming language, or may be implemented as with discrete electrical components or as at least one hardwired application specific integrated circuits (ASIC) custom designed just for this purpose.
[0033] It will be readily apparent to those skilled in this art that various changes and modifications of an obvious nature may be made, and all such changes and modifications are considered to fall within the scope of the appended claims. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims and their equivalents. | A method distributing traffic information includes: receiving location and identification information from a first wireless device; calculating a speed of the first wireless device; and transmitting data selected from the group consisting of speed, location, and identification information of the first wireless device to a second wireless device. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application Ser. No. 60/529,726, filed on Dec. 15, 2003, the specification of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates generally to an efficient mail processing and verification system and, more particularly, to a system and method for verification of cryptographically generated information where data necessary for duplication detection is in the form of the address block digital image.
Postage metering systems print and account for letter mail postage and other unit value printing such as parcel or flat delivery service charges and tax stamps. These systems have been both electronic and mechanical. Some of the varied types of postage metering systems are shown, for example, in U.S. Pat. Nos. 3,978,457; 4,301,507 and, 4,579,054. Moreover, other types of metering systems have been developed which involve different printing systems such as those employing thermal printers, ink jet printers, mechanical printers and other types of printing technologies. Examples of these other types of electronic postage meter are described in U.S. Pat. Nos. 4,168,533 and 4,493,252. These printing systems enable the postage meter system to print variable alphanumeric and graphic type information.
Card controlled metering systems have also been developed. These systems have employed both magnetic strip type cards and microprocessor-based cards. Examples of card controlled metering systems employing magnetic type cards include U.S. Pat. Nos. 4,222,518; 4,226,360 and, 4,629,871. A microprocessor (“smart card”) based card metering system providing an automated transaction system employing microprocessor bearing user cards issued to respective users is disclosed in U.S. Pat. No. 4,900,903. Moreover, systems have also been developed wherein a unit having a non-volatile read/write memory which may consist of an EEPROM is employed. One such system is disclosed in U.S. Pat. Nos. 4,757,532 and 4,907,271.
Postage metering systems have also been developed which employ cryptographically protected information printed on a mail piece. The postage value for a mail piece may be cryptographically protected together with other data by computing a Cryptographic Validation Code (CVC) that is usually included in a Digital Postage Mark (also referred to herein as a DPM). The Digital Postage Mark is a block of machine (and sometimes also human) readable information that is normally present on a mail item in order to provide evidence of paid postage (more precisely evidence of appropriate accounting action by the mailer responsible for the mail item). A CVC is a value that represents cryptographically protected information, which authenticates the source of data (e.g. a postage meter and sometimes its user) and enables verification of the integrity of the information imprinted on a mail piece including postage value. Another term sometimes used for the CVC is a digital token. Examples of postage metering systems which generate and employ CVCs are described in U.S. Pat. Nos. 4,757,537; 4,831,555; 4,775,246; 4,873,645 and 4,725,718 and the system disclosed in the various United States Postal Service published specifications such as Information Based Indicium Program Key Management System Plan, dated Apr. 25, 1997; Information Based Indicia Program (IBIP) Open System Indicium Specification, dated Jul. 23, 1997; Information Based Indicia Program Host System Specification dated Oct. 9, 1996, and Information Based Indicia Program (IBIP) Open System Postal Security Device (PSD) Specification dated Jul. 23, 1997.
These systems, which may utilize a device termed a Postage Evidencing Device (PED), employ a cryptographic algorithm to protect selected data elements by using the CVC. The information protected by the CVC provides security to detect altering of the printed information in a manner such that any unauthorized change in the values printed in the postal revenue block is detectable (and importantly automatically detectable) by appropriate verification procedures.
Typical information which may be protected as a part of the input to a CVC generating algorithm includes the value of the imprint (postage), the origination zip code, the recipient addressee (destination) information (such as, for example, delivery point destination code), the date and a serial piece count number for the mail piece. These data elements when protected by using CVC (which is generated by applying a secret or private key) and imprinted on a mail piece provide a very high level of security which enables the detection of any attempted modification of the information in the Digital Postage Mark also known as postal revenue block, where this information may be imprinted. These digital metering systems can be utilized with both a dedicated printer, that is, a printer that is securely coupled to an accounting/cryptographic module such that printing cannot take place without accounting and the printer can not be used for any purpose other than printing DPM, or in systems employing non-dedicated printers together with secure accounting systems. In this latter case, such as the case of personal (PC) or network computing systems (realized as wide area or local area), the non-dedicated printer may print the DPM as well as other information.
CVCs need to be computed and printed, for example, in the DPM for each mail piece. The CVC computation transformation requires a secret (or sometimes it is also called private key), that has to be protected and may be periodically updated. In digital metering systems, the CVCs are usually computed anew for every mail piece processed. This computation with secret (symmetric) key involves taking input data elements such as mail item serial piece count, value of the ascending register, date, origination postal code and postage amount and encrypting this data with secret keys shared by the digital meter (a.k.a. postage evidencing device or PED or Postal security Device or PSD) and postal or courier service and by the Postage Evidencing Device and device manufacturer or vendor. This sharing requires coordination of key updates, key protection and other measures commonly referred to as a symmetric key management system. The computation of the CVC takes place upon request to generate a DPM by a mailer. This computation is performed by the PSD or PED. Thus, the PSD needs to have all the information required for computation, and, most significantly, encryption key(s). Moreover, refilling the meter with additional postage funds sometimes also requires separate key and a key management process.
Various enhanced systems have been developed including systems disclosed in U.S. Pat. Nos. 5,454,038; 5,448,641 and 5,625,694, the entire disclosures of which is hereby incorporated by reference.
As noted above, it has been recognized that computerized destination address information can be incorporated into the input to the CVC computation. This enables protection of such information from alteration and thus provides basic and fundamental security. The inclusion of the destination address information in the CVC insures that for an individual to perpetrate a copying attack by copying a valid DPM from one mail piece onto another mail piece without payment and entering the mail piece with copied DPM into the mail stream, the fraudulent mail piece must be addressed to the same addressee as the original valid mail piece. The inclusion of destination address information enables automatic detection of unauthorized copies. If this has not been done, the fraudulent mail piece would not be detectable (as having an invalid DPM upon verification at a mail processing facility) without creation and maintenance of huge data bases containing identities of all previously accepted and processed mail items.
It has also been recognized that a level of enhanced security can be obtained by generating the CVC using a subset of destination address information. This concept is disclosed in published European Patent Application Publication No. 0782108, filed Dec. 19, 1996 and published Jul. 2, 1997. The published European application discloses, inter alia, the use of the hash code of a predetermined appropriate part of each address field as an input to the CVC computation process. It is suggested that the first 15 characters of each line can be selected as such appropriate part of each address field for authentication purpose. It is also suggested that an error correction code is generated for the selected address data using, for example, Reed Solomon or BCH algorithms. A secure hash value (e.g. a value computed by using SHA-1 algorithm (or Secure Hash Algorithm) in accordance with ANSI X9.30.2-1997 Public Key Cryptography for the Financial Industry—Part 2: The Secure Hash Algorithm (SHA-1) of this part of the address field data is generated, which is sent to a vault (a.k.a. Postal Security Device) along with the requested postage and other appropriate data as described above. This information, pre-defined portion of the address field, is a part of a request for the DPM generation. The PSD, which may be coupled to a personal computer (PC), generates the CVC using this data. The error correcting code is printed on the mail piece in alphanumeric characters or bar code format. During a verification process, an OCR/Mail Processing System reads the delivery address from the mail piece and the data from the DPM. Using an OCR or bar code reader, the error correcting code is also read. An error-correction algorithm is executed using the read error correcting code. If errors are not correctable, then the recognition and control process is notified of a failure. If errors are correctable, the appropriate section of each address field is selected for authentication. A secure hash value of the selected data is generated during the verification process. A secure hash value and the postal data are then sent to the verifier which then generates a CVC that is compared to the CVC printed on the mail piece to complete the verification process. (If two CVCs are identical the mail piece is accepted and verification process terminates and if they are not the mail piece is rejected). The use of error-correction algorithm is motivated by the requirement that all data that needs protection has to be hashed before it can be encrypted using a digital signature algorithm. One of the main improvements of the present patent application lies in the use of a new hybrid digital signature scheme that avoids hashing of at least one part of the data that has to be digitally signed. This allows a room for at least some errors in the address recognition process without any sacrifices of the application security.
The critically important requirement for digital metering is user-friendliness and low cost. Traditional systems of copy attack detection employ destination address information incorporation into the CVC computation. Such is the IBIP system developed by USPS referenced above. The IBIP system requires the use of 11 digit postal ZIP code (delivery point postal code) as the destination address-identifying element. This requirement creates several significant problems. First, up to 20% of all US postal addresses do not have 11 digit ZIP code (e.g. apartments in apartment buildings or mail locations in office buildings). Second, all foreign addresses do not have 11 digit ZIP code. Third, the database containing 11 digit ZIP codes must be regularly updated since postal addresses may change their ZIP codes. The USPS IBIP specification requires that in order to use digital metering in PC-based system (a.k.a. “open” systems) mailers must use a certified postal address database that must be updated at least quarterly. These requirements represent significant and in some cases fatal inconvenience to mailers. As a result PC-based digital metering is grossly disadvantaged compared to other methods of postage evidencing. For example, if mailer is using a full value first class postage and do not provide any postal ZIP code in the destination address, he/she is still entitled to full spectrum of delivery services from USPS or other carriers as appropriate. Furthermore, in many cases users of PC-based or other digital metering systems do not have access to computerized destination address information or, for the reasons of convenience, time and cost, do not want to enter such information into their digital metering systems. In these cases the security of the postal revenue collection system relies entirely on a secure linkage between printing and accounting and, possibly, on an extensive postal duplicate detection process using large data bases that store unique identities of all already processed mail items.
Previously known solutions to the problem of Digital Postage Mark (DPM) duplication (also known as copying or replay) fall into 3 categories.
First category involves printing in the DPM additional (sometimes hidden) information that would be difficult to reproduce using conventional printing means. A good example of this solution is Digital Watermarks (see “Information Hiding”, edited by S. Katzenbeisser and F. Petitcolas, Artech House, Norwood, Mass., 2000 pp. 97-119). The main disadvantages of Digital Watermarks are twofold. First, Digital Watermarks are still reproducible by dishonest mailers albeit with significantly more difficulty because the cost of reproducing them is higher than simple copying of DPM using a conventional copier or a scanner/printer combination. Second, the automated verification of Digital Watermarks in large quantities requires high resolution specialized and possibly slow scanning equipment. Such equipment is normally not employed by Posts in their mail processing facilities and could be very costly. Employment of such scanners as a general mail scanning apparatus would jeopardize traditional mail sorting since such scanners would capture mach more information that is needed for sorting and thus would require significantly more computing power to process such information.
The second category of copy protection techniques makes use of the destination address information as a piece of information uniquely indicative of the mail item. As it was noted above, the use of a sufficiently deep (e.g. uniquely indicative of delivery point) postal code as an address identifier (such as for example 11 digit ZIP code in USA that is uniquely indicative of the recipient mail box) is extremely (and sometimes fatally) inconvenient for mailers. On the other hand, the use of the full destination address information (e.g. in ASCII format) from the postal verification viewpoint is very difficult because this information in practice can not be recreated during the DPM verification process without at least some errors. It has been discovered that many mail pieces have destination addresses that are difficult and sometimes impossible to fully read, such that the DPM (including the CVC) imprinted on the mail piece cannot be verified. These conflicting requirements brought discovery of an Address Identifier (AI) system described in U.S. Pat. No. 6,175,827, issued Jan. 16, 2001. It makes use of certain additional information (such as a structure of the destination address block) and error correction codes to significantly improve robustness of the automatic address reading. This process works in practice but it is not always economical because of the amount of additional information that must be generated, imprinted and processed including computation of error correction codes for a broad variety of addresses. Another disadvantage of the Address Identifier systems is the fact that known error correction codes are not designed to work with text processing systems and therefore are not optimal. Besides, such Address Identifier systems still must be robust enough, so that they can be reproduced without errors even in a relatively error-prone OCR address recognition systems. The Address Identifier is first computed from the address information and then hashed and encrypted (digitally signed) along with other data elements that require protection. The robustness of the Address Identifier could not always be guaranteed and the error recovery process can become an essentially manual exercise, slow and costly.
The third category for solving the copy protection problem, which is described in pending U.S. patent application Ser. No. 10/456,416, filed Jun. 6, 2003, makes use of Digital Signatures schemes with partial message recovery but requires input of computerized destination address information on the part of the mailer during mail generation process. In this context and everywhere below the computerized destination address information is defined as a string of characters that are fully encoded according to one of the standard character encoding scheme such as ASCII or EBCDIC. Thus, the third approach requires that mailer must have computer-encoded string of characters representing destination address for the mail piece at the time of mail creation. This excludes, for example, handwritten or already pre-printed destination addresses that mailer may wish to use for sending his/her mail pieces. Of course, mailer can always enter such addresses into his computer or postage meter, but that may represent significant inconvenience. It should be noted that mailers can use some accurate OCR system to process image of the Destination Address Block and convert it to a string of characters before computing CVC. This case then become analogous to the case described in the aforementioned U.S. patent application Ser. No. 10/456,416, but this may represent also a cost and processing inconvenience for mailers.
A first object of the present invention is to create a system that would make use of the digital image of destination address block (with or without postal codes) in order to enable detection of unauthorized (or suspect) copies of the DPM based solely on the information available on the mail item itself.
Another object of the present invention is to develop a general technique for authentication and data integrity protection of information contained in digital images. In the general field of digital image processing there are known techniques designed for image indexing, storage and retrieval using image indexing. Digital image indexes created according to the present invention would not only enable storage and retrieval of digital images but also enable verification of authenticity and data integrity of the information present in indexed images.
SUMMARY OF THE INVENTION
The present invention relates to robust Digital Postage Mark (DPM) verification systems, increasing the percentage of mail pieces where automatic DPM verification can be achieved, even when destination addressee information is not computerized (e.g. not represented in ASCII format) during mail item creation process and may not be able to be recreated error-free during DPM verification process. The present invention also delivers enhanced ability to automatically capture addressee block information during mail sorting operation by providing on each mail piece in addition to address block itself some or all destination address image information in other areas of the mail piece.
The approach taken in the present invention avoids all the issues and difficulties of Digital Watermarks, Address Identifiers and computerized destination address data.
The main idea of the present invention is to hide (during the mail creation/finishing process) some (uniquely representative) portion of the digital image of the destination address block inside the Digital Signature evidenced in the CVC portion of the Digital Postage Mark. This can be accomplished using Digital Signatures schemes with partial message recovery. One known example of such a signature is described in ANSI X9.92-2001 Draft Standard “Public Key Cryptography for the Financial Services Industry: PV-Digital Signature Scheme Giving partial Message Recovery”.
The present invention makes use of an element of digital data defined as the Robust Address Block Image Digest (or RABID) that is created during DPM generation process from the digital image of the destination address block. The RABID is then included into recoverable portion of the digital signature and imprinted or otherwise attached to the mail item.
During the DPM verification process the representative portion of the Destination Address Block Image (that is RABID) can then be retrieved in its original form from the digital signature itself assuming that the digital signature (CVC) is represented in a highly readable code such as, for example, PDF417 or DataMatrix two-dimensional bar codes. The retrieved portion of the image then can be compared with the similar RABID portion obtained from the scanned destination address block obtained during normal mail scanning and processing activities and their proximity to each other can be determined. If they are close (in the sense of a pre-defined proximity measure defined below), then the DPM is declared authentic and postage is judged to be paid by the mailer and the mail piece can be processed and delivered with confidence. If, on the other hand, they are not close, the DPM is declared to be a copy or a counterfeit of another DPM and the mail piece can be subjected to further investigation, perhaps using forensic or other means.
The proximity measure (or a distance function) between two portions of the destinations address block image obtained from two different sources can be, for example, a Hamming distance or any other suitable proximity measure or distance.
The main advantage of the process of using Digital Signatures schemes with partial message recovery is the fact that it avoids hashing of the recoverable portion of the message and thus avoids the major source of errors associated with the Address Identifier approach. This process is also very economical in the size of the Digital Signature avoiding any significant increase in the footprint of the DPM. Thus, this process is uniquely suited for applications involving DPM copies detection, since it is robust and flexible and does not impose an overhead cost of a large footprint of imprinted data.
Thus, it has been discovered that the objective of linking the DPM with the mail piece itself through its destination address can be substantially satisfied, worldwide, for all categories of mail, domestic and international, without employing the United State Postal Service eleven digit destination point delivery code (DPDC) or its equivalents or computerized destination address information at all.
It has also been discovered that the new method does not require access to the regularly updated large address databases and works for all mail items regardless of their destination by detecting unpaid mail items, and simultaneously allowing processing of legitimately paid items even undeliverable as addressed, in this case supporting determination of their undeliverability.
It is important to notice that due to its image nature the method of present invention works equally well with non-European addresses, i.e. addresses presented in the form of Asian hieroglyphs (such as Kanji or Hiragana).
It is another object of the present invention to provide a practical universal system for linking a mail piece identity to a CVC.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the present invention may be obtained from the following detailed description of the preferred embodiment thereof, when taken in conjunction with the accompanying drawings, wherein like reference numerals designate similar elements in the various figures, and in which:
FIG. 1 is a block diagram of a system for creating, and printing mail pieces with DPM that embodies the present invention;
FIG. 2 is a graphic representation of a mail piece printed by the system shown in FIG. 1 and includes Destination Address Block and DPM printed in a form of a two-dimensional bar code;
FIG. 3 Destination Address Block DAB accessible area;
FIG. 4 is a block diagram of a system for verifying mail pieces with DPM that embodies the present invention;
FIG. 5 is a flow chart of the mail piece generation process employing the present invention;
FIG. 6 is a flow chart for computation of DABP Decision Function;
FIG. 7 is a flow chart of the verification process of the mail piece created in accordance with the process shown on FIG. 5 , and
FIG. 8 Flow chart of PIVI Decision Function Computation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The main purpose of the DPM is to evidence that postage for a given mail item has been paid or properly and securely accounted for and will be paid in the future. Various implementations for the DPM have been proposed. In selecting an implementation, it is desirable that the DPM satisfy the following set of requirements:
1) Information printed in the DPM should be linked with payment or secure accounting for the due postage. 2) Each DPM should be unique. 3) Each DPM should be robustly linked with the mail item for which it provides evidence of payment. 4) The DPM verification process should be simple and effective, e.g., it should be completely automated except for mail pieces requiring special handling or attention or (if desired) it should be a simple manual process that can be performed by mail carriers who handle mail for delivery. In practice this requirement translates into mail item self-sufficiency, i.e. full sufficiency of the information present on the item for its DPM verification.
The first requirement is usually satisfied using cryptographic techniques. In its simplest form the link between the payment and the DPM is achieved by printing in the DPM cryptographically protected information that authenticates the information imprinted on the mail piece (the CVC) that can be computed only by the device in possession of secret and protected information (a cryptographic key). This key serves as an input to an algorithm producing, for example, a message authentication code (MAC) or a Digital Signature. Each access to the key results in accounting action such as, for example, the subtraction of the postage value requested by the mailer from a postage accounting register holding prepaid postal money.
The second requirement provides a reference mechanism for detection of unauthorized duplication/copying of the DPM. Printing a unique identification on each mail piece satisfies this requirement.
The third requirement is desirable in order to simplify the detection of reused or duplicate indicia. In particular, it is very desirable to achieve the verification of the DPM without access to any external sources of information, such as databases of already used and verified DPMs. This requirement considerably simplifies means for satisfying the last requirement. Postage meters usually meet this requirement either by the use of printers securely linked to accounting means and specialized printing inks, or by linking information on the mail piece itself to the DPM.
The present invention, as described herein, addresses the requirement of the linkage between the mail piece data and the DPM. This linkage has been provided by inclusion in the CVC of data that is unique to a mail piece. Of all the data normally present on the mail items, there is only one candidate of such unique data, namely the destination address. By incorporating an image of the destination address into the CVC along with other relevant information such as date, postage amount and device identification, the PSD effectively eliminates possibility of reusing once issued (and paid for) DPM information for unpaid mail pieces, with the exception of mail pieces destined to exactly the same address on the same day (and possibly time). This last possibility on the one hand subjects the attacker to a high risk of detection, for example, by direct examination of mail items by a mailman, i.e., a delivery person, since mail pieces that are addressed to the same addressee on the same day are easily observable, while on the other hand deliver little economic benefit to the attacker. Thus, it is highly desirable to include the destination address image data into the input to the CVC computation and in doing so protect destination address information from undetectable alteration.
Pintsov-Vanstone (PV) Digital Signature Scheme with Partial Message Recovery
Pintsov-Vanstone Digital Signature Scheme with Partial Message Recovery is described in detail in a draft American National Standard ANSI X 9.92-2001 Public Key Cryptography for the Financial Services Industry: PV - Digital Signature Scheme Giving Partial Message Recovery . This Signature scheme provides a foundation for the present invention.
In the DPM applications, all messages (i.e. informational messages) that need to be signed have a fixed short size, typically smaller than 160 bits (20 bytes). Under this assumption, it has been discovered that the PV-Digital Signature scheme with partial message recovery seems to be the most appropriate security mechanism for mailing application. The description below is given for the PV-Digital Signature algorithm using Elliptic Curve Cryptographic scheme. It should be expressly noted that other signature algorithms based on the difficulty of solving discrete logarithm problem or any signature algorithms with partial message recovery are equally suitable for the purpose of present invention. These include, for example, DSA algorithm specified in ANSI X 9.30-1 Public Key Cryptography for the Financial Services Industry—Part 1 : Digital Signature Algorithm ( DSA ). This and other standards referenced in the present patent application are available from American National Standards Institute, ABA, Standards Department, 1120 Connecticut Avenue, N.W. Washington, D.C. 20036.
Below, the plaintext that needs to be signed is designated as Postal Data or PD. First the plaintext PD is divided into two parts, namely a part C that represents data elements that in addition to being protected by signature can be recovered during the verification process from the signature itself and a part V that contains data elements available in the plaintext within the DPM. This means that
PD=C∥V,
where operation “∥” as usual means concatenation.
It is noted that the integrity of the data elements in V is also protected since V is also signed. This separation of the PD into two parts fits our application perfectly. Due to a variety of traditional, marketing, postal accounting, appearance and human readability requirements, some data elements in the DPM and on the mail item itself must be present for immediate visual examination (e.g. by the recipient). These data elements include destination address, date, postage value and the postal code of location where mail piece was originated. These elements with the exception of the destination address are candidates for the part V. Other data elements such as the destination address, value of a serial piece count, the value the ascending register, e-mail address of the sender and/or recipient, telephone or fax number of the sender and the like can form the part C. These data elements allow for a cost effective organization of a number of special postal services such as a proof of deposit and delivery and mail tracking and tracing. However, since V is going to be hashed, V can be extended for all desired elements as long as they are present in a plaintext form elsewhere in the DPM or on the mail item itself. For the purpose of the present invention, the part C comprises critical information about digital image of mail item destination address, i.e., Robust Address Block Image Digest (or RABID) portion of the address block image fully described below.
The setup for the signature scheme is as follows. Let P be a public point of order n in the group of points of the elliptic curve E (Fq) over the finite field Fq (the total number N of points on the curve is divisible by n). For security reasons minimal size for n is approximately 20 bytes (160 bits). Such elliptic curve cryptographic scheme setting is referred to below simply as 160 bit elliptic curve. Each mailing system, such as the system generally designated 10 in FIG. 1 , has an identity. As used herein, mailing system 10 has an identity IA. The identity IA may contain a number of additional parameters and attributes besides strictly identification information for the system (comprising computer 12 and scanner/printer 14 ), its PSD 20 and mailer's identity itself. These parameters depend on application requirements and may include an expiration date, allowed maximum postage value or allowed maximum number of DPMs to be produced by the terminal, an indication of allowed geographical area where a mail item 30 (with DPM 32 ) produced by the terminal can be deposited, etc. The identity IA is assigned prior to the beginning of operations by the Post or a designated by the Post registration authority such as a vendor trusted by the Post. The identity IA is printed in the PD portion of DPM in plaintext.
It is assumed that the Post either functions as a Certificate Authority (CA) or uses one of the established Certificate Authorities. In its capacity as a CA, the Post generates a random integer c between 0 and n. The integer c is the postal system wide private key. The corresponding postal system wide public key is B=cP. In this case, the secrecy (confidentiality) of c against cryptanalysis is as usual protected by the difficulty of elliptic curve discrete logarithm problem.
The mailing system 10 generates a random positive integer kA<n, then it computes the value kAP and sends this value to the Post or a registration authority using, for example, a public communication network such as Internet. It is noted that this phase could in fact be done using a long-term private/public key pair from a more traditional X.509 certificate key pair. This can be done once for a given period of time or for a given number of authorized DPMs that can be generated by the terminal.
The Post generates a random positive integer c A smaller than n and the computes the point γ A on the curve
γ A =k A P+c A P,
In mailing applications, the value γ A is called “Optimal Mail Certificate or OMC”.
Next the Post computes another value
f=H (γ A ∥I A ),
where H is a hash function. Hash function H could be any suitable hash function, for example, SHA-1 described in ANSI X 9.30.2-1997 Public Key Cryptography for the Financial Industry—Part 2: The Secure Hash Algorithm (SHA-1) and“∥” denotes the operation of concatenation. At this point, various restrictions on the data included in I A and in the DPM can be tested. The Post then computes its input m A to the mailer's private key a as follows:
m A =cf+c A mod n
and sends values γ A , m A and I A to the mailer's terminal A. This portion of the protocol is executed once for a period of time prior to mail generation/verification operation.
The mailer's terminal A computes its private key a and its public key Q A as follows:
a=m A +k A mod n=cf+k A +c A mod n
Q A =aP=cfP+γ A =fB+γ A
This is also done once for a period of time determined by security and application considerations.
The private key a is used by mailing system 10 to compute the validation code CVC from the plaintext PD using a digital signature with partial message recovery described below. Observe that the private key a is a function of a postal system wide private key c and mailer-specific postal private parameter c A as well as the mailer's private parameter k A . This means that both mailer and Post (or its authorized agent) participate in creation of private key a and thus make it more difficult for any intruder to compromise the private key for mailing system 10 . Note also that the CVC verification key Q A is a function of only the public parameters and is computable from the OMC γ A , postal system wide public key B and the hash value f, thus eliminating significant security requirement of protecting private keys enabling complete self-sufficiency of mail item during verification process.
DPM Cryptographic Validation Code Generation Process Using PV Digital Signature
The PV-Digital Signature generation algorithm for the message
PD=C∥V
begins as usual with the generation of a random positive integer k<n by mailing system 10 (shown by a way of example in FIG. 1 ). The system performs the following computations:
1) R=kP;
R is a point on the curve that is formatted as a bit sting for the transformation defined in the step 2;
2) e=Tr R (C),
where Tr R is a bijective transformation parametrized by R and designed to destroy any (algebraic) structure that C might have. Transformation Tr may be a symmetric key encryption algorithm such as DEA or AES or simply the exclusive-or (XOR) operation if C at most the length of R (in Elliptic Curve Cryptographic Scheme based on the curve over Fq where q=2 160 R has the length of 160 bits). The secrecy of R is protected as usual by the difficulty of the discrete log problem and a random choice of k. [See American National Standard X 9.62-1999 : Public Key Cryptography for the Financial Services Industry: The Elliptic Curve Digital Signature Algorithm ( ECDSA ).]
3) d=H(e∥I A ∥V),
where H is a hash function and I A is the identity of mailing system 10 .
4) s=ad+k(mod n),
where a is the private key of mailing system 10 computed as described above.
5) Pair (s, e) is the signature (the validation code CVC) and it is presented for verification in the DPM together with the portion V of the plain text PD and the address block of the mail item.
Note that step 2 is computationally efficient if the size of C is less than or equal to the size of R and the transformation Tr is exclusive-or. In one embodiment of the present invention, the size of C determines how much of the destination address information can be effectively (with low overhead) hidden inside the signature and it is up to 20 bytes. This means that in the most straightforward character-encoding scheme up to 20 characters of the address information can be recovered from the CVC during verification process.
DPM Verification Process
The DPM verification process begins with the capture of the DPM from a mail piece together with destination address image information and parsing the DPM data into the values I A , CVC=(s, e), V and γ A . Then a postal verifier (such as shown in FIG. 4 ) performs the following computations:
1) Q A =fB+γ A ,
where Q A is the mailing system public key, the computation of which is described above, and B is the system wide postal public key; note that B does not need to be known outside of the postal verification system.
2) d=H(e∥I A ∥V); 3) U=sP−dQ A ; 4) X=Tr −1 U (d), recovering a new value X by the inverse transformation Tr −1 parameterized by the value U. 5) Check the redundancy of X, that is computed a distance between RABID of the destination address image captured form the address block and the corresponding RABID portion of X recovered from the CVC and declare C=X and accept the signature (and mail item) as valid if the distance is less than predefined and agreed upon threshold. The process of verification of redundancy and distance computation is described in detail below.
If the plaintext PD (and thus C) is small, then the PD can be “hidden” within the PV signature in its entirety. The size of C and efficiency of the computation in step 2 of the signature generation process and the size of CVC (because of the “e” portion) are connected. If C is larger than 20-bytes elliptic curve key the efficiency of signature computation can be adversely affected. However, 20 bytes of address data in C provide plenty of protection against existential forgery. Finding two different addresses with identical and carefully selected data elements each comprising 20 characters in such a way that both addresses are desirable targets for mail communication is a very difficult task. In addition, it has been discovered, as it will become apparent from the description of Distance Function in the following section, that the recoverable portion of the destination address image RABID can be changed from mail item to mail item or from day to day without adding any complexity to the verification process. This means that even if a dishonest mailer were to discover a computational method of finding two different addresses with identical recoverable RABIDs, the computational effort of finding them would have to be repeated for every mail piece and every day even for repeatable mailings. This would make it prohibitively expensive to utilize such computational method on any commercial scale that could represent even a remote danger to the integrity of postal revenue collection system. Thus, it is highly unlikely that anybody would spend large computational time and effort to find such pairs of addresses for the purpose of stealing a few dollars worth of postage. However, it also must be expressly noted that the present invention allows to increase the size of C to any desirable value and thus to achieve additional security at the expense of computational and space efficiency. Even additional artificial redundancy (beyond natural redundancy present in the structure and image of mailing addresses) can be added to the destination address image if desired. For example, some parts of the digital image can be repeated twice in the C portion of the PD so that after C has been recovered from the PV digital signature it would contain certain parts repeated twice.
In one embodiment (described below) of the present invention, it is assumed that the length of C is 20 bytes (160 bits) which delivers plentiful protection against any known forgery methods without significant adverse effect on both the size of the CVC and the computational efficiency of the DPM generation and verification processes. It is noted that in the future the security requirement for the size of elliptic curve crypto system cryptographic key will force its increase, thus allowing for corresponding increases in the size of C without any additional penalty. Since the amount of information in postal addresses is not expected to increase, this will provide for additional security without any at all extra penalty of computational or size inefficiency.
RABID and Distance Function
The present invention provides for a recovery of a pre-specified portion of the digital image mail piece destination address information from the value of the PV-Digital Signature as described in the previous section (see steps 4 and 5 in the section DPM Verification Process above). As noted, this pre-specified portion of the destination address is referred to as a Robust Address Block Image Digest or RABID. Once the RABID has been obtained by the verification device from the DPM it must be compared with the corresponding RABID portion of the address block image that has been captured from the digital image of mail item' destination address block, for example, during the course of normal scanning and sorting process by mail processing equipment. This comparison process takes a form of computing the value of a distance function between two portions of the destination address image and comparing it with a threshold set up before hand by application security requirements. This section describes one method of specifying suitable RABID and a suitable distance functions. Other methods are also possible within the scope and the spirit of present invention by meeting certain general criteria. More specifically, the algorithm of computing RABID should satisfy the following requirements:
1) RABID should be easily computable during mail generation process for any address 2) RABID should be easily reproducible with reasonably high fidelity during normal mail processing/verification process; 3) Finding two significantly different addresses with identical RABIDs should be computationally difficult (i.e. very time consuming). This means finding RABIDs collisions should be materially expensive for potential perpetrators; 4) RABID should change from mail piece to mail piece and from day to day to prevent multiple use of colliding addresses in the unlikely case that they are found by potential attacker.
The algorithm for selecting recoverable portion of the destination address is referred to as the RABID Algorithm. In the description below, typical US addresses are used to illustrate the present invention. Addresses in other countries may have a different format than US addresses but they always can be formatted into a more or less similar information block suitable for the purpose of the present invention. As previously mentioned, it is important to notice that the present invention works equally well with non-European addresses as well, i.e. addresses presented in the form of Asian hieroglyphs (such as Kanji or Hiragana).
Typical mailing addresses in the western industrial world consist of several lines of characters and occupy a rectangular area with a length of 1 to 2 inches and a height (width) of 0.5 to 1 inch.
Referring now to FIG. 2 , consider a traditional commonly encountered postal destination address in USA. For example, normal representation of the destination address 34 on mail item 30 may look like:
Ms. Coriandra Vost 123 South Main Street Shelton Conn. 06484
A digital binary image of this address from a computational viewpoint represents a collection of black and white picture elements (pixels). During postal processing, the digital image of the address block is normally scanned at several (typically 8) gray levels and then converted to a black and white image by the process known as binarization. One embodiment of the present invention assumes operations on binary images, but can be adopted easily for any other image representation, including gray scale images. During mail creation process the mail item or its part containing destination address block is scanned by a scanner having scanning resolution similar to the scanning resolution of scanners employed by postal processing equipment expected to process the mail item. This is typically 200-260 dots per inch. The destination address block is located in the mail item image (as a rectangular area) with its position identified with respect to the origin, that is normally for the letter mail the bottom left corner of the mailing envelope. Similar arrangements are made for parcels and other mail items that are not flat and processed by different than letter mail scanning equipment. In any case, after the address block has been located its image is binarized and parsed into lines and words. The system then generates a description of the address block in terms of the number of lines and words contained in the address. In the example above the description consists of 3 lines, with the number of words in each line beginning from the top as 3, 4 and 3 respectively. The length of each line can be measured as well together with the height of the address block. In our example above it can be 1.5 inch, 2 inches and 1.5 inch and 0.7 inch respectively.
Now data capacity that is required for the adequate representation of RABID is computed. For example, consider address with N lines, NW 1 words for first line, NW 2 words for the second line and so on. Assuming that NW 1 , NW 2 , . . . , NWlast can be represented by decimal number less than 8 (which covers all meaningful addresses) the total data capacity required for the line description is bounded by 3N bits, since each decimal digit less than 8 can be represented by 3 bits. For the addresses of up to 6 lines this requires 18 bits of data. Furthermore, assuming that the length in inches of each line can be sufficiently represented by 2 decimal digits each requiring 4 bits of information, the data capacity for the length information representation is 8N. For the address of 6 lines this amounts to 48 bits of data and has to be complemented by another 8 bits to represents the height of the address block in inches. Thus, the full description of the address block image in terms of its composition and size normally takes up to 18+48+8=74 bits of data. This description is referred to as Destination Address Block Profile or DABP. As it will become apparent below, DABP is further divided into computed and measured parts that are treated separately during verification routine. It is noted that the DABP, as defined herein) is highly robust in the sense that it can be reproduced with high fidelity by a broad variety of computers operatively connected to scanners with any scanning resolution. (In practice scanners used for mail creation and verification processes can be made comparable in their ability to see large and small details of the images such as address block and its connected components, i.e. words and lines). It should be also noted that any attempt by potential perpetrators to create (artificially) different addresses that would have the same composition and layout (number and length of lines, number of words etc.) by artificially breaking lines of addresses or creating extra spaces between words is easily detectable during normal address block scanning and observable during manual carrier sequencing manual sorting. Finally, it should be noted that the compositional and layout data of the address block DABP that is retrievable from the PV signature during mail scanning/sorting process is very useful in assisting mail processing equipment in avoiding parsing errors, namely errors associated with parsing address block into lines and words.
As described for the embodiment above, the recoverable portion of the PV signature is 160 bit (in 160 bit elliptic curve setting). Thus, additional 160−74=86 bits (beyond 74 bits used by DABP) are available for inclusion into RABID. To meet the requirements stated above these 86 bits should be selected in such a way that they would change from day to day, and thus prevent potential reuse of once found colliding addresses. One method that can be used here is the use of a traditional format for the date (e.g. DDMMYY) as a pointer to a location within the address block image. The DDMMYY data can be hashed (for example, by using secure hashing algorithm such as SHA-1 referenced above) to randomize it. Then certain portion of the resulting hash value can be used to specify X and Y coordinates of the desired location. For example, first 7 bits of hash value can be normalized to be a number between 0 and 1 that would represent relative value of X coordinate of the desired random location. In this case X=0 would represent leftmost position of an accessible area of the address block with respect to the origin and X=1 would represent its rightmost position. The Y coordinate is treated in exactly the same manner. It is expressly noted that the part of hash value chosen to specify (X, Y) coordinates could be any desired part of hash value (typically between 120 and 160 bits in total size). This is because all bits in the binary representation of hash value are equiprobable.
Computed in such a way (X, Y) coordinates define a location of a randomized point within the image of the address block. This location shall be referred to below as pivotal location or Pivotal Point (PP). Using pivotal point as a bottom left hand corner of a square image block, a pre-specified portion of the address block image is selected. This portion can be, for example, Z×Z pixels representing an image block of total Z 2 pixels. In the preferred embodiment Z=9 because 160 bits is the total amount of information that can be protected within the recoverable portion of the PV signature scheme defined over 160 bit elliptic curve finite field. Thus, an area of 9×9 pixels containing 81 bits of data is selected leaving extra 5 bits of data for redundancy purposes (from total 86 bits of data protected within PV signature after 74 bits have been used for DAPP). This Z×Z pixels portion of the image shall be referred to as the Pivotal Image or the PIVI.
In practice, the relative normalized value of X coordinate of the pivotal point PP should be between 0 and 1. Care must be taken to insure that a 9×9 pixels PIVI image with its left bottom corner at (X, Y) always fall within accessible area of the address block digital image (for both mail creation and verification processes) even in the case when pivotal point coordinates obtained during verification process from the address block are in error (i.e. not exactly matching pivotal point coordinates computed during mail creation process and retrievable from CVC (e.g. PV signature)). That means that the search area for matching two PIVIs should compensate for 9×9 image plus border area defined by maximum allowed error (1≦R≦Rmax) in finding pivotal point PP during DPM verification process. This can be achieved by selecting an area (referred to as the Accessible Area) of the destination address block in such a way that the X and Y coordinates of the pivotal point are within an area smaller than the entire address block image by a pre-specified parameters. These parameters are determined by the scanning resolution and the size of the address block and the maximal allowed error R in finding pivotal point within the address block during verification process. This process insures that a correlation function between two pivotal images PIVIs obtained from two different sources can always be computed for all desired positions of the pivotal point PP within the address block as described below. FIG. 3 depicts a typical destination address block 30 with shaded area designating Accessible Area 310 for pivotal points for matching PIVIs.
PIVI is denoted as a function PIVI (x, y) where x and y coordinates take 9 values each and the value of PIVI (x, y) could be either 0 or 1 for white and black pixels respectively. In other words PIVI (x, y) is a binary square matrix with 9 rows and 9 columns. The domain of PIVI definition is over the entire image of the destination address block.
The Pivotal Block (PIVI) represents second (randomized) portion of the RABID. Thus, RABID consists of fixed (for a given address) portion of data DABP and variable portion of data PIVI, dependent on the date (and possibly time) of mailing. Robustness of PIVI recovery from the image of the address block during verification process depends on the resolution of the verification scanner. If a high resolution scanner is employed and especially if the scanning resolution of PIVI generation process is significantly mismatched with the scanning resolution of the verification scanner, finding good match even for legitimate (non duplicated pieces could be difficult) due to relatively small amount of data in the PIVI (only 81 bits). In order to achieve desirable robustness the PIVI may be computed with much coarser (and comparable resolution) during both DPM generation and verification process. For example, if scanning resolution of both processes is between 200 to 260 dpi (as in the preferred embodiment), the PIVI may be computed with the artificial scanning resolution of 70-80 dpi. This is achieved by taking, for example, 3×3 blocks of the original scanned image and “gluing” them together into one pixel whose value (black or white or 0 or 1) is determined by the average number of black (white) pixels in the 3×3=9 pixels area of the original image of the destination address block. In other words 3×3 blocks with the predominance of black pixels are declared black while the 3×3 blocks with the predominance of white pixels are declared white and. This is very similar to multi-resolution correlation technique for template matching described in the book by R. Duda and P. Hart “ Pattern Classification and Scene Analysis ”, Wiley-Interscience, New York, 1973 pp. 332-334. This means that for the purpose of computing PIVI the image of the destination address block can be viewed with any desired resolution lesser than the resolution of imaging scanners employed during mail piece creation and verification processes (providing that desired resolution is integer multiple of the resolution of the originally scanned image).
Proximity measure (utilizing a distance function) should be used such that it maximizes error tolerance. Because the RABID value consists of two portions, (DABP and PIVI) the distance function used for the purpose of the present invention is divided into two separate functions that operate independently on DABP and PIVI portions of RABID. Since the extraction of DABP is very robust by virtue of the DABP definition, the first distance measure is defined simply as the difference between numbers of lines and words and their sizes respectively in the two values of DABP, one stored in the DPM information and another computed from the destination address block during DPM verification.
For example, let
NLines denote the number of lines in the address block; NW 1 denote the number of words in the first line of the address block; NW 2 denote the number of words in the second line of the address block; NWLast denote the number of words in the last line of the address block; LengthLine 1 denote the length of the first line of the address block (in inches, millimeters or any other appropriate measurement units represented with two decimal digits as described above); LengthLine 2 denote the length of the second line of the address block; LengthLastLine denote the length of the last line of the address block; HeightAB denote the height (width) of the address block.
Then,
DABP=( N lines, NW 1 , NW 2, . . . , NW Last, LengthLine1, LengthLine2, . . . , LengthLastLine, Height AB ).
Let DABP 1 be the destination address block profile computed during mail generation process and stored in the DPM as a part of the RABID 1 using PV signatures algorithm as described above, while DABP 2 is the destination address block profile computed during DPM verification as a part of the RABID 2 .
Formally,
DABP1=(1 N lines, 1 NW 1, 1 NW 2, . . . , 1 NW Last, 1LengthLine1, 1LengthLine2, . . . , 1LengthLastLine, 1Height AB );
DABP2=(2 N lines, 2 NW 1, 2 NW 2, . . . , 2 NW Last, 2LengthLine1, 2LengthLine2, . . . , 2LengthLastLine, 2Height AB ).
The first distance function is defined as follows:
DABPDistance=CompDABP+MeasDABP=|1 N Lines−2 N lines|+|1 NW 1−2 NW 1|+|1 NW 2−2 NW 2+ . . . +|1 NW Last−2 NW Last|+|1LengthLine1−2LengthLine1|+|1LengthLine2−2LengthLine2 |+ . . . +|1LengthLastLine−2LengthLastLine|+|1Height AB− 2Height AB|.
where ∥ denotes absolute difference operator.
DABP Decision Function:
Referring now to FIG. 6 , the computation of the DABP Decision Function is shown. At step 600 , a pre-specified threshold TrDABP is computed or selected. At step 610 , CompDABP is computed. At step 620 , if CompDABP: >0, then, at step 630 , the mail piece is rejected as a suspected duplicate and a manual investigation process begins. If CompDAB=0, at step 620 , then MeasDABP is computed at step 640 . At step 650 , if MeasDABP>TrDABP, then, at step 630 , the mail piece is rejected as suspected duplicate and the manual investigation process begins. If MeasDABP≦TrDABP, at step 650 , then, at step 660 , a PIVI Comparison calculation is performed.
In short, the DABP Decision Function is a comparison between DABPDistance and a pre-specified threshold TrDABP resulting in the following decision function:
If CompDABP=|1NLines−2Nlines|+|1NW1−2NW1|+|1NW2−2NW2|+ . . . +|1NWLast−2NWLast|>0, Then reject the mail piece as suspected duplicate and begin manual investigation process; If CompDAB=0 and MeasDABP>TrDABP, Then reject the mail piece as suspected duplicate and begin manual investigation process; If CompDAB=0 and MeasDABP≦TrDABP Then perform PIVI Comparison calculation.
PIVI Comparison and PIVI Decision Function
The PIVI comparison calculation is based on a computation of correlation function between the binary image PIVI 1 (template) obtained from the DPM and the binary image PIVI 2 captured from the digital binary image of the destination address block obtained during verification process. Thus, PIV 1 =PIV 1 (x, y) for all points (x, y) defined over 9×9 regions of destination block image (domain of the template) and PIVI 2 =PIVI 2 (x, y) for all points (x, y) of the address block digital image. The PIVI comparison algorithm is a variant of the classic template matching technique utilizing correlation function and described, for example, in “ Pattern Classification and Scene Analysis”, by R Duda and E. Hart published by Wiley-Interscience, New York, 1973 pp. 273-284. The task of comparison between two PIVIs is simpler in the case of the present invention compared to the general task of template matching described in “Pattern Classification and Scene Analysis”, by R Duda and E. Hart because in the case of the present invention the expected location of PIVI within the address block is generally known as a pre-determined (albeit randomized) function of the date of DPM imprint. In order to insure error tolerance and robustness of the process and in order to minimize the number of false alarms (when legitimately paid mail items are flagged as suspicious by the verification procedure) the process of computing correlation function is repeated multiple times using different pivotal points as a basis. The algorithm works as follows:
PIVI Comparison algorithm:
1. Retrieve Date of DPM creation DDMMYY from the DPM; 2. Using Date obtained at step 1 compute randomized coordinates (X0, Y0) of the Pivotal Point PP as described above; 3. Select Repeat Parameter R (1≦R≦Rmax) where Max is an integer that is determined by application requirements such as computational speed of verification computer and the amount of time allocated for the verification process. The repeat parameter R defines the number of correlation function computations that will be performed to achieve robustness of the matching process when only translation (shift) errors can occur. It should be expressly noted that similar correction process is established by multiple repeated computation if rotation (orientation) errors are of concern (see “Digital Image Processing” by W. Pratt, Wiley-Interscience Publication, 1991, pp 669-671). In general both sources of errors, namely translations (shifts) and rotations (orientation) can be compensated for according to the process described below. In practice computation of the small correlation function with 81 values at 4(Rmax) 2 locations is very fast and parameter Rmax can have a value between 3 and 5 resulting in the number of computed values for correlation function between 36 and 100. 4. For x=X0, x=X0+1, x=X0−1, x=X0+2, x=X0−2 . . . , x=X0+R, x=X0−R and y=Y0, y=Y0+1, y=Y0−1, . . . , y=Y0+R, y=Y0−R
compute
CorrVal( x,y )={ΣΣ[PIVI2( i,j )·PIVI1( i−x,j−y )]}/{ΣΣPIVI2( i,j ) 2 } 1/2 ,
where double summation takes place over all i and j within the domain of the translated (shifted) template PIVI 1 . The result is an array of 4R 2 values CorrVal (x, y). It should be noted that a fast computation of CorrVal (x, y) can be performed in a frequency domain using Fast Fourier Transform. (see “Digital Image Processing” by W. Pratt, Wiley-Interscience Publication, 1991, pp 196-203) 5. Select or compute the value TrPIVI that represent desired threshold for decision concerning authenticity of the DPM. TrPIVI can be pre-determined or determined based on a tolerance for the loss of postal revenue due to the fraud, identity of the mailer or postage meter/mailing machine, postage value, amount of the noise in the scanned address block image and other or similar parameters and can be adjusted from mail item to mail item based on measured characteristics of the image such as signal to noise ratio as well as information captured from the DPM. Thus, TrPIVI is generally a function of parameters that can be measured from the image and captured from the DPM. It should be expressly noted that other application-dependent definition of threshold value TrPIVI are within the scope and spirit of the present invention 6. Compute maximum value of the correlation function for 4(Rmax) 2 locations (x, y) in the in the image of the destination address block: max CorrVal (x, y) 7. Compute PIVI authenticity decision function according to the following algorithm:
PIVI Decision Function: If max CorrVal (x, y)≧TrPIVI, Then accept DPM as valid. If max CorrVal (x, y)<TrPIVI, Then reject DPM and begin mail piece manual investigation.
Referring now to FIG. 8 , the computation of the PIVI Decision Function Computation is shown. At step 800 , the value of TrPIVI is computed or selected and a maximum of CorrVal (x, y) is computed. At step 810 , CorrVal (x, y) and TrPIVI are compared. At step 820 , if max CorrVal (x, y)≧TrPIVI, then, at step 830 , the DPM is accepted as valid. At step 840 , max CorrVal (x, y)<TrPIVI, the DPM is rejected and mail piece manual investigation begins.
Mail Item Generation Process
It is assumed that in one embodiment of the present invention the mailer would be in possession of a printer equipped and a scanner capable of finding and scanning address block of the mail piece. It is assumed that the mailer also has access to a Postal Security Device (PSD) that either can be a part of the mailer's mailing system or located at a remote server site accessible from the mailing system. The PSD is designed to perform all secure cryptographic computations described above.
It is assumed also that the PSD is operatively connected to a control computer equipped with data entry or communications means and capable of driving printing means. It should be expressly noted that the control computer can be any suitable computer such as a PC, a palm pilot or a computer normally employed in postage meters to control all of its processing functions.
Referring now to FIG. 5 , the mail item generation process begins at step 500 . At step 510 , the mailer puts assembled mail item into an office printer or a mailing machine equipped with a scanner. The scanner finds and scans address blocks and control computer computes RABID 1 from scanned information as described above (i.e. the profile DABP 1 and the image PIVI 1 ). At step 520 , the control computer uses RABID 1 as recoverable portion C according to the method described above and sends this portion to the PSD for signature (CVC) computation. At step 530 , the PSD formats the C portion of the CVC according to the routine described above together with other required (and known in the art data such as postage value, date etc.) for DPM information computation. At step 540 , the PSD sends the DPM information to the control computer for formatting and printing on the mail item (or a label or other suitable media, for example, RFID Tag). At step 550 , the control computer formats the DPM (e.g. in the form of DataMatrix two-dimensional bar code) and sends this information to the printer for printing either on the label or mail item itself. At step 560 , the printer prints the DPM on a suitable media. If the DPM is printed on a label or a RFID tag the mailer attaches label to the mail item either manually or through a mechanized process. At step 570 , the process reverts to a next piece and the given mail item is ready for induction into postal stream for processing.
Mail Item Verification Process
It is assumed for the purpose of the present invention that the DPM is physically represented on the mail item in an identifiable location in a suitable machine-readable format. For example, the DPM is customarily printed in the form of a two-dimensional bar code 36 such as DataMatrix ( FIG. 2 ).
Referring now to FIG. 7 , the mail verification process works as follows. At step 700 , a mail item that is a subject to DPM (payment) verification is scanned by a mail verification system 400 ( FIG. 4 ) and the digital image of the mail item is obtained. At step 710 , the digital image of the mail item is parsed and both DPM and Destination Address Block (DAB) areas are identified, captured, enhanced (through normal digital image enhancement process) and binarized. At step 720 , the DAB is subjected to another parsing routine that extracts the DABP 2 portion RABID 2 in accordance with the method described in the above section RABID and Distance Function. At step 740 , a check is made for artificially breaking lines of addresses or unusually large extra spaces. If detected, the process continues at step 780 and terminates the verification process and reverts to manual investigation of suspect item. If none are detected, then, at step 740 , the DPM is parsed into the plain text area and the CVC area is interpreted (as ASCII data) and decrypted into the recoverable portion RABID 1 and the remaining data. At step 750 , the RABID 1 portion is separated into DABP 1 and PIVI 1 portions. At step 760 , The DABP Decision Function is computed according to the method described in the section RABID and Distance Function using DABP 1 obtained from the CVC and DABP 2 obtained from the scanned destination address block DAB. This procedure either terminates the verification process and reverts to manual investigation of suspect item at step 780 , or continues to step 785 . At step 785 , an accessible area of the DAB ( FIG. 3 ) is extracted from DAB according to the algorithm described above. The PIVI decision function is computed using PIVI 1 image obtained from the CVC and PIVI 2 image captured from the scanned destination address block DAB. At step 790 , a determination is made whether the mail item is suspect. If suspect, then the verification process terminates because the mail item is suspect and reverts to manual investigation. If not suspect, then at step 795 , the mail item is accepted as a legitimately paid one.
While preferred embodiments of the present invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, deletions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as limited by the foregoing description but is only limited by the scope of the appended claims. | The present invention uses an element of digital data that is created during digital postage mark (DPM) generation process from the digital image of the destination address block. The digital data is included into recoverable portion of the digital signature and imprinted on a mailpiece. During DPM verification, a representative portion of a destination address block image is retrieved in its original form from the digital signature itself. The retrieved portion of the image then can be compared with the similar digital data obtained from the scanned destination address block obtained during normal mail scanning and processing activities. If the comparison is under a predetermined threshold, then the DPM is declared authentic and the mailpiece can be processed and delivered with confidence. If, on the other hand, the threshold is not met, the DPM is declared a copy or a counterfeit of another DPM and the mailpiece can be subjected to further investigation. | 6 |
RELATED APPLICATION
The present application is based on, and claims priority from, Taiwanese Application Ser. No. 92126026, filed Sep. 19, 2003, the disclosure of which is herein incorporated by reference herein in its entirety.
BACKGROUND
1. Field of Invention
The present invention relates to an antenna apparatus. More particularly, the present invention relates to method and apparatus for improving antenna radiation patterns.
2. Description of Related Art
Mobile telephones are portable and wireless telephone devices installed on conveyances, such as vehicles and ships, or carried by a user. Mobile telephones are different from wireless extensions of the wired telephones or long distance radio transceivers. Mobile telephones provide users with the benefits of the same functions of and greater convenience than wired telephones. Connecting with international direct dialing, mobile telephone users can communicate with any other person in the world within coverage of a mobile telephone system.
A mobile telephone network system comprises mobile telephone switching offices (MTSO), base stations (BS) and mobile stations (MS). Generally, the mobile telephone network system may have one or more than one MTSO's, which comprise switches and communication devices, and govern a certain number of base stations. The communication devices of the MTSO are connected to the base stations.
A cellular wireless network is composed of several cells, and every cell has its own transmitting/receiving module (TRM), control channels (CC) and communication channels. The base station services one or more cells according to coverage requirements and with different antenna designs. The quantity, coverage regions, and frequency bands of the channels can be selected according to the service requirement of the cellular wireless network.
The mobile station is the mobile telephone mentioned above, which is a radio transceiver and a control unit for sending signals to the base station. When the mobile station intents to communicate with any other person, signals are transmitted to the MTSO via a wireless channel of the base station assigned to the mobile station, and then are forwarded to a public switched telephone network (PSTN). Every mobile station can receive and make a call from a subscribed MTSO, and also can make a call from other MTSO's by roaming. Besides, when a mobile station in use moves from one cell to another, the channel of the mobile station is automatically switched to that of the new cell.
From the above descriptions, when the base station services a larger quantity of mobile stations in a region such as a downtown area with a large population, the base station must have a larger capacity for dealing simultaneously with the higher communication load from many mobile stations. The mobile telephone network system applies a frequency reuse technique to increase the system capacity, and thus a large quantity of the base stations must be deployed.
Generally, the antenna used in the base station is a directional antenna, called a sector antenna, and the advantage of the antenna is that the energy of the antenna can be concentrated on a sector region. For the mobile telephone network system, the directional antenna is very helpful to the deployment of the base stations. However, in practice, the antenna radiation pattern of the sector antenna has an unwanted back lobe that radiates energy backward to other cells.
Since a cellular system adopts the above-mentioned frequency reuse technique, two signals of the same channel arriving at a mobile station from different base stations will interfere with each other. Thus, a larger back lobe of the base-station antenna radiation pattern will cause more interference to the service regions of other base stations. Also, the base-station antennas are usually mounted on top of buildings. Therefore, the back lobe radiations will more likely cause co-channel interferences to adjacent base stations assigned with the same frequencies.
In the prior art, in order to prevent mobile stations from co-channel interferences between different base stations and the communication quality thereof from being affected, the usual solution is to increase the distances between base stations using the same channels. However, this solution reduces the quantity of base stations in a certain area, and decreases the signal strengths over some regions in the certain area. Also, if the base-station antenna is mounted on top of a building, a conventional approach for reducing the co-channel interferences is to place a metal-grid panel behind the base-station antenna to shield the back-lobe radiation. However, this conventional method would affect the outer appearance of the base station, increase the wind resistance of the base-station antenna, require higher cost, need more construction efforts, and yet only provide smaller improvement.
SUMMARY
Accordingly, the invention uses the electromagnetic scattering principle to design electromagnetic scattering structures configured on a radome of an antenna to improve the antenna radiation patterns. The material of the electromagnetic structure is conductive. According to the electromagnetic principles, when electromagnetic waves illuminate conductive materials, induced currents will be excited on the conductive materials. Therefore, currents will be induced on the electromagnetic scattering structures due to the electromagnetic waves from the base-station antenna, and the induced currents then generate secondary radiation electromagnetic waves. The secondary radiation electromagnetic waves will interfere with the electromagnetic waves from the base-station antenna, and thus improve the antenna radiation patterns of the base station.
It is therefore an objective of the present invention to provide a method for improving antenna radiation patterns, which effectively reduces the back lobe of the antenna radiation patterns, to decrease the energy radiating to areas not covered by the base station, and mitigate interferences between adjacent base stations.
It is another objective of the present invention to provide a method for improving antenna radiation patterns in the horizontal plane, of which the energy outside the service region is reduced to mitigate the co-channel interferences or the adjacent-channel Interferences between the base stations. Or, the service region is increased to enlarge the coverage area of the base station.
It is still another objective of the present invention to provide a method for improving antenna radiation patterns in the vertical plane, of which the down-tilted angle of the main lobe is varied, so that the service of a base station is improved for the mobile stations positioned below.
It is still another objective of the present invention to provide an electromagnetic scattering structure, which is configured on a radome of the base station to adjust easily the antenna radiation patterns without any change of the size of the base-station antenna. Thus, one may replace the metal-grid panel, which is more expensive, hard to construct, and only a smaller improvement.
It is still another objective of the present invention to provide a radome with different functions for mobile communication system operators to choose according to requirements in different areas, so as to reduce the energy in regions not covered by the base station, and enlarge the coverage area of the base-station antenna or enhance the energy radiating downward from a base station on top of a building to the mobile stations positioned below.
In accordance with the foregoing and other objectives of the present invention, method and apparatus for improving antenna radiation patterns are provided. The electromagnetic scattering structure has a conductive layer with certain patterns, and is applied on the radome of the base-station antenna. The electromagnetic waves radiating from the antenna therein induce scattering effects, which, together with the electromagnetic diffractions from the rear metal panel of the antenna, can substantially reduce the back lobe and the fields in regions not covered by the antenna. Thus, the antenna radiation patterns are improved.
In the electromagnetic scattering structure of the present invention, the pattern of the conductive layer is designed according to a central working frequency of the antenna, and has variations of patterns and arrangements according to different demands. The units of the pattern, whether the type thereof is single or mixed, have a variety of modifications in their sizes, arrangements or quantities, and the purpose thereof is to improve the antenna radiation patterns. For example, the electromagnetic scattering structures, which comprises units of the same type but with different lengths, can adjust the antenna radiation pattern in the horizontal plane to change the level of the back lobe, the half-power beam width of the main lobe, or the energy radiating to certain directions from the base station.
According to preferred embodiments of the invention, the material of the conductive layer is metal, such as copper, and an adhesive layer is configured between the patterned conductive layer and a shell of the radome to stick the patterned conductive layer on the shell. Moreover, the present invention further comprises a protective layer, which is configured on one side of the patterned conductive layer opposite to the shell, to protect the patterned conductive layer. In addition, the patterned conductive layer is configured on an inner wall or an outer wall of the shell.
The pattern of the conductive layer comprises a plurality of units, such as strip units, cross units, U-shaped units, meandered square units or their combinations. The length of one of these units is a half, an integer multiple, or a certain multiple of a corresponding wavelength at the central working frequency of the antenna.
According to another preferred embodiment of the present invention, the patterned conductive layer is directly embedded in the shell, and the shell of the radome is therefore used to protect the conductive layer.
According to another preferred embodiment of the present invention, the pattern of the conductive layer comprises a plurality of slot units, such as spiral slot units. The slot units are a plurality of openings of the conductive layer, i.e. the slots of the conductive layer. The electromagnetic waves are scattered when they are transmitted through the discontinuous place, such as the interface between the conductive layer and the openings of this preferred embodiment. Therefore, the slot unit of the opening type can also be used in the present invention to form the pattern.
The embodiments of the invention provide several patterns for the conductive layer. Most can suppress the electromagnetic diffractions from the rear metal panel of the antenna, such that the energy radiating backward is reduced. The application of the same type but with different lengths can adjust the antenna radiation pattern in the horizontal plane to change the level of the back lobe, the half-power beam width of the main lobe and the energy radiating to certain directions from the base station. In addition, the electromagnetic scattering structures comprising different units can decrease the energy radiating to areas not covered by the base station, as well as decreasing the back lobe of the antenna radiation pattern.
In conclusions, the invention can decrease the energy radiating to areas not covered by the base station, and increase the energy radiating to the service regions of the base station or change the direction of the radiation of the antenna. Therefore, besides decreasing the cost of installing more base stations, the inventions further allow the energy of the antenna radiate more effectively to the coverage area. Moreover, the application of the invention is easy and convenient, and performs well, thus providing an economic and practical method and apparatus.
It is to be understood that both the foregoing general description and the following detailed description are examples, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings, where:
FIG. 1 illustrates a front view of the base-station antenna;
FIG. 2A illustrates a schematic view of the first embodiment of the present invention;
FIG. 2B illustrates a far-field antenna radiation pattern in the horizontal plane of the first embodiment;
FIG. 2C illustrates a far-field antenna radiation pattern in the vertical plane of the first embodiment;
FIG. 3A illustrates a schematic view of the second embodiment of the present invention;
FIG. 3B illustrates a far-field antenna radiation pattern in the horizontal plane of the second embodiment;
FIG. 3C illustrates a far-field antenna radiation pattern in the vertical plane of the second embodiment;
FIG. 4A illustrates a schematic view of the third embodiment of the present invention;
FIG. 4B illustrates a far-field antenna radiation pattern in the horizontal plane of the third embodiment;
FIG. 4C illustrates a far-field antenna radiation pattern in the vertical plane of the third embodiment;
FIG. 5A illustrates a schematic view of the fourth embodiment of the present invention;
FIG. 5B illustrates a far-field antenna radiation pattern in the horizontal plane of the fourth embodiment;
FIG. 5C illustrates a far-field antenna radiation pattern in the vertical plane of the fourth embodiment;
FIG. 6A illustrates a schematic view of the fifth embodiment of the present invention;
FIG. 6B illustrates a far-field antenna radiation pattern in the horizontal plane of the fifth embodiment;
FIG. 6C illustrates a far-field antenna radiation pattern in the vertical plane of the fifth embodiment;
FIG. 7A illustrates a schematic view of the sixth embodiment of the present invention;
FIG. 7B illustrates a far-field antenna radiation pattern in the horizontal plane of the sixth embodiment;
FIG. 7C illustrates a far-field antenna radiation pattern in the vertical plane of the sixth embodiment;
FIG. 8A illustrates a schematic view of the seventh embodiment of the present invention;
FIG. 8B illustrates a far-field antenna radiation pattern in the horizontal plane of the seventh embodiment;
FIG. 8C illustrates a far-field antenna radiation pattern in the vertical plane of the seventh embodiment;
FIG. 9A illustrates a schematic view of the eighth embodiment of the present invention;
FIG. 9B illustrates a far-field antenna radiation pattern in the horizontal plane of the eighth embodiment;
FIG. 9C illustrates a far-field antenna radiation pattern in the vertical plane of the eighth embodiment;
FIG. 10A illustrates a schematic view of the ninth embodiment of the present invention;
FIG. 10B illustrates a far-field antenna radiation pattern in the horizontal plane of the ninth embodiment; and
FIG. 10C illustrates a far-field antenna radiation pattern in the vertical plane of the ninth embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
The following descriptions use a base-station antenna for third generation mobile communications to be an example for illustrating several embodiments of the present invention. As illustrated in FIG. 1 , a base-station antenna 100 comprises an array antenna 102 and a radome 104 . The array antenna 102 comprises a plurality of antenna units 112 , and the antenna units are enclosed in the radome 104 . The base-station antenna 100 is a sector antenna, of which the central working frequency is about 2 GHz. The electromagnetic wavelength corresponding to the central working frequency is about 150 mm. The length of the radome 104 is 1302 mm, the width thereof is 155 mm, the depth thereof is 69 mm and the thickness thereof is 2 mm. The relative dielectric constant of the material of the radome 104 is 2.73. Under these conditions, the characteristics of the antenna radiation patterns for the base-station antenna 100 are: the half-power beam width of the main lobe in the horizontal plane (θ=90°): 64°; the half-power beam width of the main lobe in the vertical plane (φ=0°): 6.5°; the front-to-back ratio: 26 dB; and the first side lobe level: −13.7 dB.
The electromagnetic scattering structure of the present invention comprises a patterned conductive layer, which is configured on the radome 104 in FIG. 1 , and, more particularly, on the shell of the radome 104 . For example, the conductive layer can be adhered on an inner wall or an outer wall of the radome 104 by an adhesive layer. Moreover, the present invention further comprises a protective layer, which is configured on one side of the patterned. conductive layer opposite to the shell, to protect the patterned conductive layer. According to another preferred embodiment of the present invention, the patterned conductive layer also can be directly embedded in the shell, and the shell of the radome is therefore used to protect the conductive layer.
In the following embodiments, the material of the conductive layer is metal, such as copper or other conductive metals.
The First Embodiment
FIG. 2A illustrates a schematic view of the first embodiment of the present invention. In this embodiment, the electromagnetic scattering structure comprises a plurality of strip units 202 . The length of the strip unit 202 is half of the corresponding wavelength at the central working frequency, which is about 76 mm, and the width of the strip unit 202 , which is not critical, is 2 mm in this embodiment. The strip units 202 are arranged periodically in two rows and in front of the antenna inside the radome 104 (i.e. the array antenna 102 as illustrated in FIG. 1 ). The two rows are configured on the surface of the radome 104 , and each is spaced a quarter wavelengths from each closer edge of the radome 104 .
FIG. 2B illustrates far-field antenna radiation patterns in the horizontal plane of the first embodiment, and the radial axis thereof represents the relative field value in dB. The curve 222 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 224 is the antenna radiation pattern with the electromagnetic scattering structure. FIG. 2C illustrates far-field antenna radiation patterns in the vertical plane of the first embodiment, and the radial axis thereof represents the relative field value in dB. The curve 232 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 234 is the antenna radiation pattern with the electromagnetic scattering structure.
From FIGS. 2B and 2C , the level of the back lobe of the embodiment is about 14 dB lower than that of the antenna radiation pattern without the electromagnetic scattering structure, and the front-to-back ratio is increased to about 40 dB. In addition, the half-power beam width of the main lobe is almost unchanged, while the fields in other angles of the horizontal plane are reduced significantly by applying the electromagnetic scattering structure; for example, the level at the azimuth 120° is 8 dB lower.
The Second Embodiment
FIG. 3A illustrates a schematic view of the second embodiment of the present invention. In this embodiment, the electromagnetic scattering structure comprises two strip units 302 . The length of the strip unit 302 is the same as the length of the radome 104 , and the width of the strip unit 302 , which is not critical, is 2 mm in this embodiment. The two strip units 302 are in front of the antenna inside the radome 104 (i.e. the array antenna 102 as illustrated in FIG. 1 ), and are configured on the surface of the radome 104
FIG. 3B illustrates far-field antenna radiation patterns in the horizontal plane of the second embodiment, and the radial axis thereof represents the relative field value in dB. The curve 322 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 324 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure. FIG. 3C illustrates far-field antenna radiation patterns in the vertical plane of the second embodiment, and the radial axis thereof represents the relative field value in dB. The curve 332 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 334 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure.
From FIGS. 3B and 3C , the level of the back lobe of the embodiment is about 34 dB lower than that of the antenna radiation pattern without the electromagnetic scattering structure, and the front-to-back ratio is increased to about 60 dB. In addition, the half-power beam width of the main lobe is almost unchanged, while the fields in other angles of the horizontal plane are reduced significantly by applying the electromagnetic scattering structure; for example, the level at the azimuth 120° is 13 dB lower. Therefore, the embodiment decreases the energy radiating to areas not covered by the base-station antenna so that interferences between adjacent base stations can be mitigated.
The Third Embodiment
FIG. 4A illustrates a schematic view of the third embodiment of the present invention. In this embodiment, the electromagnetic scattering structure comprises a plurality of cross units 402 . Each of the cross units 402 has two strip portions 412 a and 412 b with identical lengths. The length of the strip portions 412 a and 412 b is a half the corresponding wavelength at the central working frequency, and the widths of the strip portions 412 a and 412 b , which are not critical, are both 2 mm in this embodiment. The cross units 402 are in front of the antenna inside the radome 104 (i.e. the array antenna 102 as illustrated in FIG. 1 ), and are configured in two rows interleaving on the surface of the radome 104 .
FIG. 4B illustrates far-field antenna radiation patterns in the horizontal plane of the third embodiment, and the radial axis thereof represents the relative field value in dB. The curve 422 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 424 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure. FIG. 4C illustrates far-field antenna radiation patterns in the vertical plane of the third embodiment, and the radial axis thereof represents the relative field value in dB. The curve 432 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 434 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure.
From FIGS. 4B and 4C , the level of the back lobe of the embodiment is about 18 dB lower than that of the antenna radiation pattern without the electromagnetic scattering structure, and the front-to-back ratio is increased to about 44.5 dB. Therefore, the embodiment effectively reduces the energy radiating backward; the half-power beam width of the main lobe in the horizontal plane becomes 75°, and thus the coverage sector is increased by 11° more than the antenna radiation pattern without the electromagnetic scattering structure.
The Fourth Embodiment
FIG. 5A illustrates a schematic view of the fourth embodiment of the present invention. In this embodiment, the electromagnetic scattering structure comprises a plurality of U-shaped combinations 502 . Each of the U-shaped combinations 502 has a first U-shaped unit 512 a and a second U-shaped unit 512 b , which are placed opposite to each other. The length of the first U-shaped unit 512 a is equal to the corresponding wavelength at the central working frequency, and the length of the second U-shaped unit 512 b is two times the corresponding wavelength at the central working frequency. The widths of the two U-shaped units 512 a and 512 b , which are not critical, are both 2 mm in this embodiment. The U-shaped combinations 502 are arranged in a row and in front of the antenna inside the radome 104 (i.e. the array antenna 102 as illustrated in FIG. 1 ).
FIG. 5B illustrates far-field antenna radiation patterns in the horizontal plane of the fourth embodiment, and the radial axis thereof represents the relative field value in dB. The curve 522 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 524 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure. FIG. 5C illustrates far-field antenna radiation patterns in the vertical plane of the fourth embodiment, and the radial axis thereof represents the relative field value in dB. The curve 532 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 534 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure.
From FIGS. 5B and 5C , the level of the back lobe of the embodiment is about 8 dB lower than that of the antenna radiation pattern without the electromagnetic scattering structure, and the front-to-back ratio is increased to about 34 dB.
The Fifth Embodiment
FIG. 6A illustrates a schematic view of the fifth embodiment of the present invention. In this embodiment, the electromagnetic scattering structure comprises a plurality of meandered square units 602 . The circumference of each of the meandered square units 602 is an integer multiple of the corresponding wavelength at the central working frequency. The width of the meandered square unit 602 , which is not critical, is 6 mm in this embodiment. The meandered square units are arranged in a row and in front of the antenna inside the radome 104 (i.e. the array antenna 102 as illustrated in FIG. 1 ).
FIG. 6B illustrates far-field antenna radiation patterns in the horizontal plane of the fifth embodiment, and the radial axis thereof represents the relative field value in dB. The curve 622 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 624 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure. FIG. 6C illustrates far-field antenna radiation patterns in the vertical plane of the fifth embodiment, and the radial axis thereof represents the relative field value in dB. The curve 632 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 634 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure.
From FIGS. 6B and 6C , the level of the back lobe of the embodiment is about 6.2 dB higher than that of the antenna radiation pattern without the electromagnetic scattering structure, and the front-to-back ratio is reduced to about 19.8 dB. Although the level of the back lobe of the antenna radiation pattern with the electromagnetic scattering structure is higher than that of the antenna radiation pattern without the electromagnetic scattering structure, the energies radiating in the azimuths 60° and 300° are about 12.2 dB less than those of the antenna radiation pattern without the electromagnetic scattering structure, and the half-power beam width of the main lobe is reduced to about 46.5°. Therefore, the embodiment reduces the coverage region of the antenna radiation pattern, and thus mitigates the interferences from or to the adjacent base stations in the directions around the azimuths 60° and 300°.
The Sixth Embodiment
FIG. 7A illustrates a schematic view of the sixth embodiment of the present invention. In this embodiment, the electromagnetic scattering structure comprises a plurality of cross units 704 and a plurality of strip units 702 a and 702 b . Each of the cross units 704 has two strip portions 714 a and 714 b with identical lengths. The lengths of the strip portions 714 a and 714 b are both 0.45 times the corresponding wavelength at the central working frequency. The length of each of the strip units 702 a and 702 b is a half the corresponding wavelength at the central working frequency. The widths of the strip portions 714 a and 714 b and the strip units 702 a and 702 b are not critical. In this embodiment, the widths of the strip portions 714 a and 714 b are 8 mm, and the widths of the strip units 702 a and 702 b are 2 mm.
The cross units 704 and the strip units 702 a , 702 b are arranged in rows and in front of the antenna inside the radome 104 (i.e. the array antenna 102 as illustrated in FIG. 1 ). Moreover, the rows of the strip units 702 a and 702 b are configured separately on the two sides of the radome 104 , and each of the cross units 704 is placed between two corresponding strip units 702 a and 702 b.
FIG. 7B illustrates far-field antenna radiation patterns in the horizontal plane of the sixth embodiment, and the radial axis thereof represents the relative field value in dB. The curve 722 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 724 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure. FIG. 7C illustrates far-field antenna radiation patterns in the vertical plane of the sixth embodiment, and the radial axis thereof represents the relative field value in dB. The curve 732 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 734 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure.
From FIGS. 7B and 7C , the level of the back lobe of the embodiment is about 6 dB lower than that of the antenna radiation pattern without the electromagnetic scattering structure, and the front-to-back ratio is increased to about 32 dB. Besides, the energies radiating in the azimuths 60° and 300° are about 18.4 dB less than those of the antenna radiation pattern without the electromagnetic scattering structure, and the half-power beam width of the main lobe is reduced to about 46.5°.
The Seventh Embodiment
FIG. 8A illustrates a schematic view of the seventh embodiment of the present invention. In this embodiment, the electromagnetic scattering structure comprises a plurality of meandered square units 804 and a plurality of strip units 802 a and 802 b . The length of each of the strip units 802 a and 802 b is half of the corresponding wavelength at the central working frequency. The circumference of each of the meandered square units 804 is an integer multiple of the corresponding wavelength at the central working frequency. The widths of the strip units 802 a and 802 b and the meandered square units 804 are not critical. In this embodiment, the widths of the meandered square units 804 are 6 mm, and the widths of the strip units 802 a and 802 b are 2 mm.
The meandered square units 804 , the strip units 802 a and 802 b are arranged in rows and in front of the antenna inside the radome 104 (i.e. the array antenna 102 as illustrated in FIG. 1 ). Moreover, the rows of the strip units 802 a and 802 b are configured separately on the two sides of the radome 104 , and each of the meandered square units 804 is placed between two corresponding strip units 802 a and 802 b.
FIG. 8B illustrates far-field antenna radiation patterns in the horizontal plane of the seventh embodiment, and the radial axis thereof represents the relative field value in dB. The curve 822 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 824 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure. FIG. 8C illustrates far-field antenna radiation patterns in the vertical plane of the seventh embodiment, and the radial axis thereof represents the relative field value in dB. The curve 832 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 834 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure.
From FIGS. 8B and 8C , the level of the back lobe of the embodiment is only increased by about 1.8 dB compared with that of the antenna radiation pattern without the electromagnetic scattering structure, and the front-to-back ratio is reduced to about 24.2 dB. The energies radiating in the azimuths 60° and 300° are about 38 dB less than those of the antenna radiation pattern without the electromagnetic scattering structure, and the half-power beam width of the main lobe is reduced to about 46.5°. Therefore, the embodiment reduces the coverage region of the antenna radiation pattern, and thus mitigates the interferences from or to the adjacent base stations in the directions around the azimuths 60° and 300°.
The Eighth Embodiment
FIG. 9A illustrates a schematic view of the eighth embodiment of the present invention. In this embodiment, the electromagnetic scattering structure comprises a plurality of meandered square units 904 . The circumference of each of the meandered square units 904 is an integer multiple of the corresponding wavelength at the central working frequency. The widths of the meandered square units 904 are not critical. In this embodiment, the widths of the meandered square units 904 are 6 mm.
The meandered square units 904 are arranged in rows and in front of the antenna inside the radome 104 (i.e. the array antenna 102 as illustrated in FIG. 1 ). Moreover, the meandered square units 904 are configured only on the lower half of the radome 104 .
FIG. 9B illustrates far-field antenna radiation patterns in the horizontal plane of the eighth embodiment, and the radial axis thereof represents the relative field value in dB. The curve 922 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 924 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure. FIG. 9C illustrates far-field antenna radiation patterns in the vertical plane of the eighth embodiment, and the radial axis thereof represents the relative field value in dB. The curve 932 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 934 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure.
From FIGS. 9B and 9C , the level of the back lobe of the embodiment is about 5.5 dB higher than that of the antenna radiation pattern without the electromagnetic scattering structure, and the front-to-back ratio is reduced to about 20 dB. The energies radiating in the azimuths 60° and 300° are reduced, and the half-power beam width of the main lobe is reduced to about 50°. Moreover, the width of the main lobe in the vertical plane becomes greater, of which the half-power beam width is about 8.5°. In addition, the direction of main lobe is down-tilted by 2.5°.
Because the base stations are usually installed at high locations, in order to enhance the service to the mobile stations below, the prior art usually down-tilts the base-station antenna mechanically, and thus changes the direction of the main lobe in the vertical plane. Another conventional method to tilt the main lobe down is by properly adjusting the relative phase angles and amplitudes of the input currents of the antenna units 112 . The embodiment provides another new way to increase the down-tilted angle of the main lobe for increasing the energy radiating downward in the vertical plane of the antenna radiation pattern. Hence, the embodiment improves the coverage quality of an elevated base station for the mobile stations positioned below.
The Ninth Embodiment
FIG. 10A illustrates a schematic view of the ninth embodiment of the present invention. In this embodiment, the electromagnetic scattering structure comprises a plurality of spiral slot units 1002 . The spiral slot units 1002 are a plurality of openings of the conductive layer, and the widths of the spiral slot units are 4 mm. The material of other portions 1004 , which are not the spiral slot units, is a conductive material such as, for example, metal, such as, for example, copper. The spiral slot units 1002 are arranged in rows and in front of the antenna inside the radome 104 (i.e. the array antenna 102 as illustrated in FIG. 1 ).
FIG. 10B illustrates far-field antenna radiation patterns in the horizontal plane of the ninth embodiment, and the radial axis thereof represents the relative field value in dB. The curve 1022 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 1024 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure. FIG. 10C illustrates far-field antenna radiation patterns in the vertical plane of the ninth embodiment, and the radial axis thereof represents the relative field value in dB. The curve 1032 is the antenna radiation pattern without the electromagnetic scattering structure of the embodiment, and the curve 1034 is the antenna radiation pattern of the antenna with the electromagnetic scattering structure.
From FIGS. 10B and 10C , in the vertical plane, the antenna radiation pattern of the embodiment varies significantly from that without the electromagnetic scattering structure. In the horizontal plane, the levels of the antenna radiation pattern in side directions are lower than those without the electromagnetic scattering structure, and the half-power beam width of the main lobe is reduced to 52°.
In conclusion, the invention effectively and conveniently changes the antenna radiation pattern without any change of the original size and appearance of the base-station antenna. The invention has various practical implementations, such as a film sticker having the electromagnetic scattering structure of the invention manufactured for being adhered directly on the radome of the base station. Moreover, optional radomes with different functions can be provided for base stations of a certain model. According to requirements of different areas, the mobile communication operators properly choose and replace radomes to improve the performance of the base-station antennas for the service regions thereof. Alternatively, when the base-station antennas are manufactured, the radomes with different functions can also be prepared to be selected by the mobile communication operators.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents. | Several electromagnetic scattering structures are designed to improve antenna radiation patterns. The electromagnetic scattering structure has a conductive layer with certain patterns, and is applied on the radome of the base-station sector antenna. The electromagnetic waves radiating from the antenna therein induce scattering effects, which, together with the electromagnetic diffractions from the rear metal panel of the antenna, can substantially reduce the back lobe and the fields in regions not covered by the antenna. Thus, the antenna radiation patterns are improved so that a lower possibility of co-channel interferences between adjacent base stations can be achieved and therefore better efficiency of the base-station coverage also can be obtained. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a packing mechanism for achieving a sealed relationship with the bore of a well conduit, which may be employed on packers, bridge plugs, tubing hangers or the like.
2. Summary of the Prior Art
Packers and bridge plugs have long been utilized in the oil and gas well industry to achieve a sealing engagement at a selected position with the bore of a well conduit, such as a casing or a tubing string. Such prior art mechanisms generally incorporate an axially compressible annular sealing unit disposed intermediate an upper slip mechanism and a lower slip mechanism. Conventionally, upward movement of the lower slip mechanism, produced by a mandrel, was transmitted to the annular sealing units and then to the upper slip element to achieve the compression, hence radial expansion of the annular packing element and the setting of the upper and lower slip elements.
This prior art arrangement has the distinct disadvantage in that the upper slip elements are exposed to the well fluids existing in the well conduit above the sealing mechanism. Hence, the upper slips are subject to accumulation of particulates and debris in and around the slip units and the cone for operating the slip units. Such accumulated particulates or other debris can often result in the failure of the upper slip mechanism to properly function.
There is a need, therefore, for a sealing mechanism for use on packers, bridge plugs, or the like wherein an annular packing element is disposed above both the upper and lower slip mechanisms, thus protecting such mechanisms from the deleterious effects of accumulation of particulates and other debris. There is the further need for a bridge plug mechanism that can be utilized below a conventional packer and the combination can be set, then unset and moved to another position in the well without requiring more than one trip into the well.
SUMMARY OF THE INVENTION
An elongated mandrel is provided which is conventionally insertable in the well by a tubing string. Surrounding the mandrel is a tubular body assemblage. The tubular body assemblage is carried into the well by a control dog and slot arrangement having the unusual characteristic of being disengagable by clockwise rotation accompanied by a tensile force on the mandrel and being re-engagable by further clockwise rotation of the mandrel accompanied by a downward force on the mandrel. The lower end of the tubular body assemblage mounts a set of conventional drag blocks which are engagable with the well conduit bore to permit rotational movement of the mandrel with respect to the tubular body assemblage.
At the upper end of the tubular body assemblage, an abutment shoulder is provided. Immediately below the abutment shoulder, an axially elongated annular packing unit is provided which, when subjected to a compressive force, expands radially into sealing engagement with the bore wall of the well conduit. Immediately below and abutting the packing unit is an upper slip assemblage including an upper cone, a slip carrier and upper slips cooperable with the upper cone to be moved outwardly into biting engagement with the well bore conduit upon upward movement of the upper slip assembly which is, of course, resisted by the annular packing element.
A lower slip assembly is mounted around the tubular body assemblage at a position below the upper slip assembly and operates entirely independently of the upper slip assembly. Such lower slip assembly may incorporate a lower cone, a lower slip holder and a plurality of peripherally spaced slips cooperable with the lower cone to be expanded into biting engagement with the conduit bore wall.
The lower slip assembly is set by the limited upward movement of the mandrel involved in effecting the release of the mandrel from the tubular body assemblage. Such setting of the lower slips is accomplished by a collet having a ring portion surrounding the mandrel. A radial pin is secured to the collet ring portion and projects through an axial slot in the tubular body assemblage to engage a movable portion of the lower slip assembly. Such movable portion could be either the slip carrier or the lower cone, depending upon which of several conventional configurations of slip assemblies is selected for use.
The latching heads of the collet are provided with grooves or threads on their outer surfaces which cooperate with wicker threads provided on the internal bore of the outer tubular body assemblage. In the run-in position of the mandrel, such latching heads are disposed in an annular recess provided on the exterior of the mandrel. As the mandrel is moved upwardly, the collet and movable element of the lower slip assembly are concurrently moved upwardly by the lower wall of the annular recess until the slip is set. Once the slip is set, further upward movement of the mandrel cams the locking heads into fixed engagement with the wicker threads on the internal bore surface of the outer tubular assembly and permits the mandrel to move further upwardly to effect the setting of the upper slip assembly and the compression of the packing element.
The setting of the upper slip assembly is accomplished by an abutment on the mandrel which engages a setting ring surrounding the mandrel having a radial pin portion protruding through an axial slot in the tubular body assemblage and engaging either the upper slip carrier or the upper slip cone, depending upon whether one or the other of such elements constitutes the lowermost portion of the upper slip assembly.
The further upward movement of the mandrel thus effects an upward movement of the upper slip assembly which translates into a compressive force exerted on the annular packing unit. Thus, the packing unit is expanded by compression into sealing engagement with the internal bore surface of the conduit and the upper slips are then expanded into biting engagement with such conduit bore wall.
After the setting of the lower slip assembly by the initial upward movement of the mandrel, one or more spring pressed locking elements mounted in the bore wall of the outer tubular assemblage move inwardly into engagement with wicker threads provided on the mandrel. Thus, retraction or downward movement of the mandrel is prevented, and when both slip assemblies and the packing unit are set, such wicker threads maintain the setting forces.
The wicker locking threads provided on the mandrel are releasable from the spring pressed locks by rotation of the mandrel in a clockwise direction. This moves the mandrel downwardly relative to the tubular body assemblage and appropriate abutments on the mandrel engage the upper slip assembly and the lower slip assembly to unset such assemblies. The locks are disengaged rotationally prior to the conclusion of such rotation of the mandrel, and the control dog and slot connections between the mandrel and the outer tubular assemblage are positioned to interengage as the mandrel moves down to its run-in position, so that the entire assemblage can be retrieved from the well by upward movement of the mandrel, or positioned and re-set above or below the previous location in the conduit.
In high pressure environments, the forces on the locking elements may cause such elements to jump over the wicker threads, particularly during the unsetting rotation of the mandrel. To prevent such undesirable occurrence without complicating the unsetting procedure, a supplemental collet may be provided intermediate the mandrel and an internal recess formed in the tubular body assemblage. The collet heads are provided with internal threads which are outwardly displaced from engagement with an elongated, externally threaded portion of the mandrel as the mandrel moves upwardly toward the setting position for the upper slips.
As the mandrel abutment engages the setting ring for the upper slips, spring biased lock segments positioned adjacent the ring portion of the supplemental locking collet move inwardly into engagement with an annular recess on the mandrel and cause the collet to move upwardly with the mandrel. Such upward movement brings the collet heads into engagement with an inclined upper end surface of the internal recess to force the collet heads inwardly to engage the threaded portion of the mandrel and positively lock the mandrel against axial displacement relative to the collet, except by relative rotation.
To unset the packing assembly, the mandrel is rotated in a clockwise direction. The collet is secured against rotation by a pin and slot connection to the tubular body assemblage, and against any substantial upward movement by an internal shoulder on the tubular body assemblage, so the mandrel is moved downwardly by the thread action of the threaded collet heads, unsetting the packing assembly.
Further advantages of the invention will be readily apparent to those skilled in the art from the following detailed description, taken in conjunction with the annexed sheets of drawings, on which is shown a preferred embodiment of the invention.
BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1A, 1B . . . 1D collectively represent a vertical quarter sectional view of a packing mechanism embodying this invention with the components thereof shown in a run-in position with respect to a well conduit.
FIGS. 2A, 2B . . . 2D are views respectively similar to FIGS. 1A, 1B . . . 1D but showing the components after the release of the mandrel from the control dog and slot connection and the upward movement of the mandrel to effect the setting of the lower slip assembly.
FIGS. 3A, 3B . . . 3D are views respectively similar to FIGS. 1A, 1B . . . 1D but showing the upper slip assembly and the annular compressible packing unit in their set positions in engagement with conduit bore wall.
FIG. 4 is a developed view of the cam slot of the control dog and slot connection.
FIG. 5 is a sectional view taken on the plane 5--5 of FIG. 4.
FIGS. 6A, 6B and 6C are views respectively corresponding to FIGS. 1A and 1B but showing the incorporation of a supplemental locking and release collet in its run-in position.
FIGS. 7A, 7B and 7C are views respectively corresponding to FIGS. 6A and 6B but showing the supplemental locking and release collet in its packer setting position.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1A, 1B . . . 1D, there is shown a hollow mandrel assemblage comprising an elongated mandrel 10 having external threads 10a at its top end for securement to a connecting sub 10b. Connecting sub 10b is conventionally connected to a tubing string (not shown) by which the mandrel 10 is inserted and retrieved from the well conduit 1.
Connecting sub 10b is provided with an external downwardly facing shoulder 10c which provides an abutment for the top end of a tubular body assemblage 20 which telescopically surrounds the mandrel assemblage. Tubular body assemblage 20 includes an upper portion 20a having a top end face 20b in abutment with mandrel shoulder 10c. The lower end of upper body portion 20a is provided with external threads 20c (FIG. 1C) to which an intermediate thick-walled sleeve 20d is threadably secured. The bottom end of intermediate sleeve 20d is provided with external threads 20e to which is secured a bottom sleeve portion 20f (FIG. 1D). A conventional drag block assemblage 22 is mounted in the bottom sleeve portion 20f and frictionally engages the bore wall 1a of the conduit 1.
A non-conventional control dog and slot connection is provided between the intermediate sleeve portion 20d of the tubular body assemblage 20 and the mandrel 10. Intermediate sleeve portion 20d is provided with a radial bore 20g (FIG. 1C) within which is mounted a control dog 21 (FIG. 1C). Control dog 21 is biased inwardly by a spring 21a which abuts a retaining sleeve 24 secured to external threads 20h provided on the top end of the intermediate sleeve portion 20d. The beveled end 21b of spring biased control dog 21 engages a specially designed ramp slot 14 formed in an enlarged shoulder portion 10d of the mandrel 10. In the preferred embodiment, two control dogs 21 are provided in diametrically spaced relationship which respectively cooperate with two diametrically spaced ramp slots 14. As best shown in the topographic view of FIG. 4, each slot 14 includes a short vertical portion 14a which communicates at its bottom with a ramped slotted portion 14b (FIG. 4) which has the effect of elevating the control dog 21 as the mandrel 10 is rotated in a clockwise direction. Concurrent application of tension to mandrel 10 permits the control dogs 21 to move downwardly around the respective ramp 14b and then up an annular ramp 14c, thus freeing the mandrel 10 for unrestricted upward movement relative to the tubular body assemblage 20. As is customary, the spring pressed guide blocks 22 resist rotational movement of the tubular body assemblage 20 sufficient to permit the disengaging rotational and upward movement of the mandrel 10 involved in releasing the control dog and slot connection previously described.
Above the end of the intermediate tubular body portion 20d, a lower slip assembly 30 is provided in surrounding relationship to the upper sleeve portion 20a of the tubular body assemblage 20. Such slip assemblage comprises a tubular lower cone 32, an upper slip carrier 34 and a plurality of peripherally spaced slips 36 mounted intermediate the lower cone 32 and the slip carrier 34. Those skilled in the art will recognize that the relative positions of the slip cone and slip carrier could be reversed, if desired, and other conventional arrangements of lower slip assemblies could be employed.
As shown in FIG. 1B, the slip retainer 34 is secured against upward movement relative to the upper body sleeve 20a by a C-ring 22 (FIG. 1B) mounted in an annular groove 20k provided on the exterior of sleeve portion 20a of the tubular assemblage 20. A retaining ring 23 surrounds C-ring 22 and is secured by threads 23a to slip retainer 34.
The movable element of the lower slip assembly 30, which in this case is the lower cone 32, is provided with a radial bore 32a into which a radial pin 38 projects, passing through an axial slot 20m in the tubular body assemblage 20. The radially inner end of pin 38 engages in a bore 40b provided in the ring portion 40a of a collet 40 and is retained in position by a sleeve 33 which engages threads 32b on lower cone 32. Collet 40 has a plurality of peripherally spaced, upwardly extending arm portions 40c which respectively terminate in enlarged head portions 40d. The radially outer faces of head portions 40d are provided with ratchet threads 40e which can cooperate with internal wicker threads 20k provided on the inner surface of the upper sleeve portion 20a. In the run-in position of the apparatus shown in FIG. 1C, the collet heads 40d are restrained from movement into engagement with wicker threads 20k by a split retaining ring 11 which is conventionally secured in an appropriate annular groove 10h formed on the exterior of mandrel 10 by a threaded cap 11b. Split ring 11 has a depending rib potion 11a overlying the ends of the collet heads 40d.
It should be noted that the collet heads 40d in their run-in positions are held within a recess 10m formed on the exterior of the mandrel 10. The lower end of recess 10m is just slightly inclined as indicated at 10n so that upward movement of the mandrel 10 will first move retaining ring 11 off collet heads 40d and then impart an upward movement to the collet heads heads 40d, thus moving the lower cone 32 upwardly by radial pin 38 and effecting the setting of the slips 36. Once the slips 36 are set, further upward movement of the collet heads 40d is prevented and the upwardly facing inclined shoulder 10n provided on the bottom end of the mandrel recess 10m rides under the collet heads 40d and the larger diameter normal surface 10g of mandrel 10 retains the collet heads in a locked position in the wicker threads 20k, thus locking the lower slip assembly in its set position.
An upper slip assemblage 50 (FIG. 1B) is mounted in surrounding relationship to the upper sleeve portion 20a of the tubular housing assemblage 20 at a point above the slip retainer 34 of the lower slip assembly 30. The upper slip assembly 50 is generally similar to the lower slip assembly 30 and includes a slip retainer 52, an upper cone 56 and a plurality of peripherally spaced slips 54 mounted intermediate the upper slip retainer 52 and the upper cone 56. The relative positions of the upper slip retainer and the upper slip cone may be reversed, or any other conventional assembly of a cone, slips and retainer may be utilized. The important thing is that the entire upper slip assembly 50 is movable relative to the upper sleeve portion 20a of the tubular body assemblage 20. A torque pin 56b may be provided in upper cone 56 which engages an axially extending slot 21 in the tubular body assemblage 20.
An axially extending slot 20n is provided in the tubular body assemblage 20 underlying the upper slip assembly 50. A radial bore 52a is provided in the upper slip retainer 52 and a radial pin 55 extends through such radial hole into engagement with a hole 58a provided in a ring 58 secured to the exterior of the mandrel 10. Pin 55 is retained in the assemblage by a sleeve 57 which is secured by threads 52c to the bottom end of the upper slip retainer 52.
A gage ring 59 is secured by threads 56a to the top end of the upper cone 56. The end surfaces of gage ring 59 and upper cone 56 abut the bottom end of an annular compressible packing element 60. While for simplicity of illustration, the element 60 is shown as a single elastomeric sleeve, those skilled in the art will recognize that any packing assemblage that is operable by the application of a compressive force thereto may be utilized.
The upper end 60a of annular packing element 60 engages an abutment structure comprising a sleeve 62 (FIG. 1A) sealably mounted on the exterior of the upper sleeve portion 20a of the tubular housing assemblage 20 by an O-ring 62a. Sleeve portion 62 has external threads which mount a gage ring 64 and the bottom end faces of gage ring 64 and sleeve 62 form an abutment for the top end 60a of the annular packing element 60. The upward movement of the packing element 60 is restrained by an abutment ring 66 which is secured by threads 66a to the extreme top end of the tubular body assemblage 20. It should be noted that the top portions of the upper sleeve 20a of the tubular body assemblage 20 is slidably engaged with an external surface 10p provided on the mandrel 10 which terminates in the downwardly facing shoulder 10c. O-ring seal 17 with back-up rings 17a are provided to seal this slidable interengagement.
The compression of the annular packing element 60, followed by the setting of the upper slips 56 is accomplished by a split ring 13 (FIG. 1B) which is conventionally secured in an appropriate annular groove 10q provided on the exterior of the mandrel 10 by a cap 13b. The spacing of the abutment ring 13 relative to the radial pin 55 is such that the lower slip assembly 30 is completely set before the abutment ring 13 engages the force transmitting ring 58 which imparts an upward movement to the slip retainer 52 by the pin 55, hence to the entire upper slip assembly 50 and the annular packing element 60. Thus, these elements are advanced to their set position by further upward movement of mandrel 10 subsequent to the setting of the lower slips and entirely independently of the setting of such lower slips. The annular packing element 60 is first compressed into sealing engagement with the internal bore wall 1a of conduit 1 and this prevents further upward movement of the cone 56, thus permitting the slips 54 to be shifted radially outwardly into biting engagement with the conduit bore wall 1a.
The entire packing assembly is retained in the set position by one or more radially shiftable lock elements 70 (FIG. 1D) which are mounted in the bottom portion 20d of the tubular body assemblage 20. Such lock elements 70 carry thread segments 70a on their inner ends and are biased radially inwardly by one or more springs 72. Springs 72 react against a cover sleeve 74 which is secured in position by the top end 25a of the bottom sleeve portion 20f which, as previously mentioned, is secured to the bottom end of the tubular body assemblage 20 by threads 20e.
In the run-in position of the apparatus, the lock elements 70 rest against an enlarged shoulder 10r provided on the lower portion of the mandrel 10. As the mandrel is elevated, the lock elements 70 ride off the shoulder 10r and engage clockwise wicker threads 10s which extend axially along the external surface of the mandrel 10.
To unset the packing assemblage, the mandrel 10 is rotated in a clockwise direction. Mandrel 10 is advanced downwardly by threads 10s until the enlarged shoulder 10r contacts the lock elements. A downwardly facing sloped surface 10w forces the lock segments 70 outwardly to release from mandrel threads 10s. The downward movement of mandrel effects the unsetting of the entire packing assemblage. Such unsetting action is accomplished by an abutment C-ring 15 which is mounted in an annular groove 10t provided on the exterior of the mandrel 10, secured by a cap 15a, and movable by downward movement of the mandrel 10 into engagement with the upper side of the ring 58, thus pulling the slip retainer 52 downwardly through the radial pin connection 55. This releases the setting forces on packing element 60 and upper slip assembly 50. The lower slip assembly 30 is unset by the abutment ring 11 moving into engagement with the collet heads 40d, pulling such heads out of engagement with the wicker threads 20k and moving the collet 40 downwardly. This effects a downward movement of the lower cone 32 through the connecting pin 38.
As the mandrel 10 completes its downward and rotational movement, the spring pressed control dogs 21 are positioned to re-enter the slot 14, and further downward and clockwise movement of the mandrel will effect the return of the control dogs and slot connections to their original run-in position in slot portion 14a.
From the foregoing description, those skilled in the art will appreciate that a unique packing assemblage is provided by this invention. Not only are all of the slip assemblies protected from the accumulation of particulates and/or well debris by the location of the packing element 60 above the upper slip assembly 50 and the lower slip assembly 30, but the entire setting operation is accomplished by an upward movement of the mandrel 10 resulting, of course, from the application of tension to the supporting tubing string. Initial rotation of the mandrel 10 in a clockwise direction with tension thereon is necessary to effect the release of the control dog and slot interconnections of the mandrel 10 and the tubular body assemblage 20.
The unsetting of the packing assemblage is accomplished by rotation in the clockwise direction of the mandrel 10, which may be accompanied by the application of a setdown force. The rotation results in the mandrel threads 10s moving downwardly relative to the locking segments 70. The downward movement of the mandrel 10 effects the unsetting of the annular packing elements 60, the upper slip assembly 50 and the lower slip assembly 30 by engagement of abutment ring 15 with force transmitting collar 58 and the engagement of split retaining ring 11 with the collet heads 40d. When this is accomplished, the control dogs 21 are aligned with the entry portion of the slot 14 and effect the re-connection of the mandrel 10 to the tubular body assemblage 20. Thus, the entire packing assemblage may be removed by upward movement of the tubing string supporting the mandrel 10 or repositioned and re-set above or below the previous location.
In the event that the aforedescribed apparatus is employed in wells wherein high pressures are encountered, it has been observed that the locking of the upper and lower slips in their position by the radially shiftable locking dogs 70 (FIG. 3D) may result in the locking dogs jumping over the ratcheting threads 10s provided on the surface of the lower portion of the mandrel 10, at least during the unsetting rotation of mandrel 10. To overcome this problem, the embodiment of this invention illustrated in FIGS. 6A and 6B may be employed. In this embodiment, wherein similar numerals represent parts previously described, a supplemental collet 80 is incorporated in the annnnular space between the mandrel 10 and the bore of the upper portion 20a of the tubular body assemblage 20. The collet 80 has a ring portion 80a slidably engaging an elongated threaded portion 10y provided on the mandrel 10. Peripherally spaced, upwardly extending arm portions 80b on the collet 80 terminate in radially enlarged locking heads 80c which are internally threaded as at 80d to cooperate with the threads 10y provided on the mandrel 10 when the mandrel is moved upwardly relative to the supplemental collet 80.
Additionally, the force transfer ring which mounts the radial pin 55 is lengthened to extend upwardly to a position just below the bottom end of the collet ring portion 80a. This enlarged force transmitting ring or sleeve 58' abuts the bottom ends of a plurality of peripherally spaced lock segments 85 which are normally held in an internal recess 20t provided in the tubular body assemblage 20 by the threaded portion 10y of the mandrel 10. A garter spring 85a urges the locking segments 85 inwardly.
Thus, in the run-in, relocation or removal position, the supplemental collet 80 has no effect on the relative movements of the mandrel 10 and the tubular body assemblage 20. However, as the mandrel 10 is moved upwardly to effect the setting of the lower slips 54 in the manner previously described, the mandrel threads 10y move upwardly past the collet heads 80c, and an annular recess 10x formed on the exterior of the mandrel 10 moves into alignment with the locking segments 85 and they snap into engagement with such recess under the influence of the garter spring 85a. The lock segments 85 thus transfer the upward movement of the mandrel 10 to the supplemental collet 80. Collet 80 is prevented from rotational movement by a radial pin 82 connecting the ring portion 80a of collet 80 with an elongated slot 22 formed in the upper portion 20a of the tubular body assemblage 20. The pin 82 slot 22 are shown in dotted lines because they are angularly displaced from the slot 21 which receives the torque pin 56b of the upper slip 56.
The resulting upward movement of the supplemental collet 80 to the fully set position, brings the top end surface 80e of the locking heads 80c into engagement with the downwardly facing inclined surface 20r which forms the top of an elongated recess 20s in tubular body portion 20a within which the collet heads 80c are mounted. The inclined surface 20r forces the collet heads 80c inwardly to effect a complete interengagement of collet threads 80d with the threaded portion 10y of the mandrel 10 which occurs while the mandrel 10 is moving to effect the setting of the upper slips 56 and the compression of the packing element 60 into sealing engagement with the wall of the surrounding well conduit. In the final setting position of the mandrel 10, (FIG. 7B) the collet heads 80c are disposed in engagement with the internal surface 20u of the tubular body assemblage and hence are prevented from jumping over the mandrel threads 10y. Further upward movement of supplemental collet 80 is prevented by a downwardly facing shoulder 20y at the top of the surface 20u (FIG. 6A).
To effect the unsetting of the packing assemblage incorporating the supplemental collet 80, it is only necessary to rotate the mandrel 10 in a clockwise direction. This moves the mandrel 10 downwardly by the threading action of the collet threads 10d against the mandrel threads 10y. Such downward movement continues until the top end of the mandrel threads 10y pass below the collet threads 80d. At this juncture, the mandrel 10 is free to move downwardly to force the locking segments 85 outwardly out of engagement with the mandrel recess 10x and permit the mandrel 10 to release the upper slips 56 (and packing 60) by moving the supplemental collet 80 downwardly by the bottom surface of connecting sub 10b, which in turn moves the force transmitting ring 58' downwardly to release the slip carrier 54 from its set position. The unsetting of the lower slips 36 occurs in the same manner as previously described so that both sets of slips are unset and the compressive forces on the packing element 60 are relieved to permit the packing assemblage to be freely moved relative to the well conduit within which it is suspended.
Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention. | A downhole packing mechanism for achieving sealed engagement with the bore of a well conduit comprises a mandrel positionable within a well by a tubing string. Surrounding the mandrel is a tubular body assemblage which is connectable to the mandrel for run-in purposes by a control dog and slot arrangement. An annular packing element surrounds the upper end of the tubular body assemblage and is compressed into sealing engagement with the well bore conduit by an upper slip assembly. A lower slip assembly surrounds the tubular body assemblage and is detachably engagable with the mandrel for setting by initial upward movement of the mandrel. Subsequent upward movement of the mandrel effects the upward movement of the upper slip assembly, the compression of the annular packing element into sealing engagement with the well conduit and the setting of the upper slip assembly. The device may be used as a packer, bridge plug, tubing hanger, or the like. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. application Ser. No. 13/629,398, filed Sep. 27, 2012; which claims the benefit of U.S. Provisional Application No. 61/540,979, filed Sep. 29, 2011, the contents of the above applications are incorporated by reference in their entireties.
REFERENCE TO SEQUENCE LISTING, TABLE OR COMPUTER PROGRAM
[0002] The Sequence Listing is concurrently submitted herewith with the specification as an ASCII formatted text file via EFS-Web with a file name of Sequence_Listing.txt with a creation date of Sep. 25, 2014, and a size of 3.8 kilobytes. The Sequence Listing filed via EFS-Web is part of the specification and is hereby incorporated in its entirety by reference herein.
FIELD OF THE INVENTION
[0003] In general, the invention relates to Lactococcus lactis strains for the production of bioactive peptides. More particularly, the invention relates to Lactococcus lactis strains, and bacterial preparations thereof, for the production of bioactive peptides having anti-hypertensive and cholesterol-lowering effects in mammals and related nutritional and therapeutic products.
BACKGROUND
[0004] Coronary heart disease (CHD), which is considered the most common and serious form of cardiovascular disease, is the first cause of death in developed industrialized countries. Hypertension and elevated blood cholesterol levels, particularly high low density-density lipoprotein cholesterol (LDL-C), are two of the major modified risk factors for the development of CHD (Department of Health and Human Services, 2000).
[0005] The long-term regulation of blood pressure is associated with the rennin-angiotensin system. The conversion of angiotensin I into angiotensin II, a potent vasoconstrictor octapeptide, by the angiotensin-converting enzyme (ACE) [EC 3.4.15.1] has long been known. Hence, the inhibition of this enzyme can reduce high arterial blood pressure through ACE-inhibitory (ACEI) compounds. However, several side effects have been associated with the ACE-inhibitory drugs. On the other hand, ACEI peptides derived from foods sources such as milk proteins are considered safer and without the side effects associated with the drugs.
[0006] Milk proteins have received increased attention as potential ingredients in health-promoting functional foods. It is accepted that proteins from milk may act as precursors of biologically active peptides with different physiological effects on the digestive, endocrine, cardiovascular, immune and nervous systems (Korhonen, 2009, J. Funct. Foods 1: 177-187). Indeed, it has been reported that an effective way to increase the amount of bioactive peptides in dairy products is by milk fermentation with highly proteolytic strains of lactic acid bacteria (LAB) (López-Fandiño et al., 2006, Int. Dairy J. 16: 1277-1293). LAB growth in milk is dependent on the specific proteolytic systems for the generation of free peptides as a source of nitrogen (Hugenholtz, 2008, Int. Dairy J. 18, 466-475). Indeed, several ACEI peptides and/or with antihypertensive activity derived from milk proteins by the action of Lactobacillus helveticus and Saccharomyces cerevisae (Nakamura et al., 1995, J. Dairy Sci. 78:777-783; Nakamura et al., 1995, J. Dairy Sci. 78:1253-1257) or Lactobacillus helveticus (Sipola et al, 2002, J. Dairy Res. 69: 103-111; Seppo et al., 2003, Am. J. Clin. Nutr. 77:326-330) have been found. As a result, there are some commercial products, such as Calpis sour milk drink (Calpis Co., Japan) and Evolus (Valio, Finland). Calpis sour milk is claimed as suitable for those with mild hypertension and is fermented with Lactobacillus helveticus and Saccharomyces cervisiae and Evolus which is claimed as the first European functional food to help lower blood pressure, also fermented with Lactobacillus helveticus . Both fermented milk products contain bioactive peptides responsible for the ACE-inhibition and presented antihypertensive effects in hypertensive rats.
[0007] These biological effects of Lactobacillus helveticus strains have been described in the prior art. For instance, international patent application WO99/16862, Yamamoto et al., describes the strain Lactobacillus helveticus CM4, FERM BP-6060 which is capable of producing a large amount of the tripeptide Val-Pro-Pro and/or Ile-Pro-Pro. Furthermore, U.S. Pat. No. 5,449,661, Nakamura et al., describes the preparation of a peptide containing the tripeptide sequence Val-Pro-Pro and its use for lowering hypertension, obtained from fermenting milk with the strain Lactobacillus helveticus JCM 1004.
[0008] Similarly, it has been shown that peptides released by Enterococcus faecalis strains from milk proteins were able to decrease arterial blood pressure in spontaneously hypertensive rats (SHR) (Muguerza et al., 2006, Int. Dairy J., 16:61-69; Quirós et al., 2007, Int. Dairy J., 17, 33-41). In fact, international patent application WO 2004/104182, relates to Enterococcus faecalis bacteria which can produce bioactive peptides, such as peptides with ACE inhibitory activity and/or antihypertensive activity. Even though LAB and the specific species Lactobacillus and Enterococccus , have been widely studied and recommended for use for the production of health-promoting peptides, there is still constant pursuit of finding new bacteria which are useful for the production of bioactive peptides from dairy proteins. To the best of our knowledge, the beneficial health effects of peptides in fermented milk with Lactococcus lactis strains have not been reported. L. lactis is one of the most important LAB, since it generally takes part of commercial starter cultures used in the manufacture of fermented dairy foods (Odamaki et al., 2011, Systematic Appl Microbiol 34, 429-434). Lactococcus lactis strains are able to improve the organoleptic characteristics of dairy products since they are responsible for the formation of aromatic compounds (Ayad 2009, Food Microbiol 26, 533-541). Previous studies in our laboratory showed that specific L. lactis strains isolated from native ecosystems were able to produce remarkable aroma profiles in fermented milk (Gutierrez-Méndez et al., 2008, J. Dairy Sci. 91, 49-579). Furthermore, it was reported that a wild L. lactis strain presented ACEI peptides in Mexican Fresco cheese (Torres-Llanez, et al., 2011, J. Dairy Sci., 94: 3794-3800). Also, specific wild L. lactis strains were explored for their ability to produce ACEI activity in fermented milk (Rodriguez-Figueroa et al., 2010, J. Dairy Sci., 93: 5032-5038; Otte et al., 2011, Int. Dairy J., 21: 229-238). However, fermented milk products produced by L. lactis strains were not tested in vivo to show any health benefits.
[0009] Therefore, there is still a great demand for finding new effective microbes which are useful both as starters in fermented dairy foods and for the production of bioactive peptides with unique health benefits.
SUMMARY
[0010] Specific Lactococcus lactis strains NRRL B-50571 and NRRL B-50572 have the capacity to produce bioactive peptides that have remarkable capacity to generate an antihypertensive effect in mammals. Such hypotensive peptides do not change arterial blood pressure in subjects with normotensive arterial blood pressure; only hypertensive subjects experiment a reduction in arterial blood pressure. The bioactive peptides are a viable option to reduce arterial blood pressure without the secondary effects commonly produced by synthetic drugs.
[0011] Additionally, such bioactive peptides improve cardiovascular health by lowering bad (LDL) cholesterol and present antioxidant properties. Therefore, the mentioned lactic acid bacteria and the bioactive peptides included in this invention may be used in pharmaceutical preparations as well as in food products, such as functional foods.
[0012] One or more embodiments include the generation of bioactive peptides by the action of novel Lactococcus lactis NRRL B-50571 or NRRL B-50572 on a substrate comprising one or more proteins or its fragments, which contain specific amino acid sequences. These peptides could be used in an edible product such as a food product, food supplement or as a pharmaceutical composition.
[0013] One or more embodiments involve the manufacture of food products with bioactive peptides as a consequence of the action of specific Lactococcus lactis NRRL B-50571 and/or NRRL B-50572; or bacterial preparation of the bioactive peptides, with or without other microorganisms, on a substrate within the food. Also, these bioactive peptides may be separately produced and added to the food product, food supplement or pharmaceutical preparation as part of the formulation, with the purpose of reducing blood pressure, lowering LDL-cholesterol (bad cholesterol) and reducing oxidation, for better cardiovascular health.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIGS. 1A and 1B are diagrams showing typical RP-HPLC peptide profiles corresponding to water soluble extracts (WSE)<3 kDa fractions obtained from the fermentation of milk by specific wild L. lactis strains (NRRL B-50571 and NRRL B-50572) at 1 A) 214 nm, 1 B) 280 nm. C=unfermented milk;
[0015] FIG. 2 presents IC 50 values of the peptide fractions obtained by hydrolysis of milk proteins with specific wild L. lactis strains obtained by RP-HPLC. Data represent mean values±SD (n=3). Statistical differences were considered with P<0.01, using one way ANOVA and Tukey-Kramer test. F=Peptide fraction. F1-F5=obtained at 214 nm; F6=obtained at 280 nm;
[0016] FIGS. 3A and 3B are typical mass spectra corresponding to a peptide sequence collected from the WSE F1 obtained from milk fermented by L. lactis NRRL B-50571: 3 A) Double-charged ion 362.9 m/z.; 3 B) MS/MS Spectrum for the specified ion in A). After interpretation and comparison in database, the fragment amino acid sequence matched with α-La (f63-68);
[0017] FIGS. 4A-4C are diagrams showing the change in blood pressure and HR during 24 h in SHR treated with milk fermented by specific L. lactis strains: ( 4 A) systolic blood pressure (SBP), ( 4 B) diastolic blood pressure (DBP) and ( 4 C) heart rate (HR). Positive control captopril, negative control saline, whey fraction of milk fermented by L. lactis NRRL B-50572-3 (35 mg protein/kg BW) , whey fraction of milk fermented by L. lactis NRRL B-50571-3 (35 mg protein/kg BW) , whey fraction of milk fermented by L. lactis NRRL B-50572-5 (50 mg protein/kg BW) , whey fraction of milk fermented by L. lactis NRRL B-50571-5 (50 mg protein/kg BW) . Data is shown by means with their standard error. Each SHR group had seven animals;
[0018] FIG. 5 is a diagram showing the change in systolic blood pressure during 4 weeks of SHR treated by L. lactis fermented milk. L. lactis NRRL B-50571 fermented milk ; L. lactis NRRL B-50572 fermented milk ; captopril=Positive control ; Purified water=Negative control . Data is shown by mean values±SEM (n=8). FM=Fermented milk;
[0019] FIG. 6 is a diagram showing the diastolic blood pressure during 4 weeks of SHR treated by L. lactis fermented milk. L. lactis NRRL B-50571 fermented milk ; L. lactis NRRL B-50572 fermented milk ; captopril=Positive control ; Purified water=Negative control . Data is shown by mean values±SEM (n=8). FM=Fermented milk;
[0020] FIG. 7 is a diagram showing plasma low-density lipoprotein cholesterol in SHR treated by L. lactis fermented milk for 4 weeks. Captopril=Positive control; Purified water=Negative control. Data is shown by mean values±SEM (n=8);
[0021] FIG. 8 is a diagram showing plasma high-density lipoprotein cholesterol in SHR treated by L. lactis fermented milk for 4 weeks. Captopril=Positive control; Purified water=Negative control. Data is shown by mean values±SEM (n=8);
[0022] FIG. 9 is a diagram showing plasma triglycerides in SHR treated by L. lactis fermented milk for 4 weeks. Captopril=Positive control; Purified water=Negative control. Data is shown by mean values±SEM (n=8); and
[0023] FIG. 10 is a diagram showing plasma total cholesterol in SHR treated by L. lactis fermented milk for 4 weeks. Captopril=Positive control; Purified water=Negative control. Data is shown by mean values±SEM (n=8);
DETAILED DESCRIPTION
[0024] The following abbreviations are used throughout the present application:
L. lactis—Lactococcus lactis; ACE—angiotensin I-converting enzyme; WSE—water soluble extract; RP-HPLC—reverse phase high performance liquid chromatography; MS—mass spectrometry; SHR—spontaneously hypertensive rats; BW—body weight; SBP—systolic blood pressure; DBP—diastolic blood pressure; HR—heart rate; PP—pulse pressure; PWV—pulse wave velocity; LAB—Lactic acid bacteria; cfu—colony-forming units; LSD—Least significant difference; SEM—mean standard error; NRRL B-50571-3—milk fermented by L. lactis NRRL B-50571 (35 mg protein/kg body weight (BW); NRRL B-50572-3—milk fermented by L. lactis NRRL B-50572 (35 mg protein/kg BW); NRRL B-50571-5—milk fermented by L. lactis NRRL B-50571 (50 mg protein/kg BW); NRRL B-50572-5—milk fermented by L. lactis NRRL B-50572 (50 mg protein/kg BW); ND—not detected; and Vs—versus.
[0047] Specific Lactococcus lactis strains NRRL B-50571 and NRRL B-50572 have the ability to produce certain bioactive peptides having a remarkable capacity for generating an antihypertensive effect in mammals. These novel strains of Lactococcus lactis were deposited at the National Center for Agricultural Utilization Research, United States Department of Agriculture, United States of America, in September, 2011, which are Lactococcus lactis NRRL B-50571 and NRRL B-50572. These bacteria were isolated from raw milk products and were Gram positive, catalase negative and coccal-shaped organisms. These bacteria were identified as Lactococcus lactis by PCR amplification of the gene acmA (Buist et al., 1995, J. Bacteriol. 177:1554-1563) with the primers PALA 4 y PALA 14 (Table 1). Strains showed the classical characteristics for Lactococcus , such as positive growth at 10 C and 4% NaCl, but lack of growth at 45 C and pH 9.6. They also presented important technological characteristics such as high proteolytic activity (8 h to coagulate litmus milk), and the ability to ferment citrate, glucose, lactose and salicin in media. Similarly, when these strains were inoculated in reconstituted nonfat dry milk, they presented high acidifying activity (4.0<pH<5.0 in 24 h) and high proteolytic activity (Abs 340>0.10 in 24 h) according to the OPA (o-phtaldialdehyde method) (Church et al., 1983, J. Dairy Sci. 66:1219-1227).
[0048] The bacterial strains Lactococcus lactis NRRL B-50571 or NRRL B-50572 were propagated in 10 mL of sterile lactose (5 g L −1 ) M17 broth and incubated at 30° C. for 24 h. Fresh cultures were obtained by repeating the same procedure. Initial starter culture were prepared by allowing L. lactis strains to reach 10 6 -10 7 colony-forming units (cfu) mL −1 as enumerated on M17 agar containing lactose (5 g L −1 ).
[0049] Production of Fermented Milk Containing Bioactive Peptides
[0050] Reconstituted nonfat dry milk (10%, w/v) was sterilized at 100° C. for 20 min. A loop of L. lactis single pre-culture (7-8 log cfu mL −1 ) of NRRL B-50571 or NRRL B-50572 was inoculated into sterilized milk. The inoculated milk was incubated for 12 h at 30° C. Then, cultures were added (3% v/v) to reconstituted nonfat dry sterilized milk to get the different fermented milk batches. Incubation was carried out at 30° C. and stopped at 24 to 48 h by pasteurization at 75° C. for 1 min.
[0051] Preparation of the Water-Soluble Extracts (WSE) from Fermented Milk
[0052] Fermented milk was centrifuged at 20,000×g for 10 min at 0° C. Then, supernatants were collected and ultra-filtered through 3 kDa cut-off membranes at 9,800×g for 6 min. Permeates were collected, filtered through a 0.45 μm disposable hydrophilic filter and frozen at −80° C. until analysis were done.
[0053] ACE Inhibitory Activity of WSE from Milk Fermented with L. lactis Strains NRRL B-50571 or NRRL B-50572
[0054] Water soluble extracts (<3 KDa) obtained after fermenting milk with L. lactis strains NRRL B-50571 or NRRL B-50572 presented high ACEI activity (>80%) and low IC 50 's (<25 μg/mL). The IC 50 is the amount of peptide content required to inhibit ACE activity by 50%. The ACE inhibitory activity was assayed by the method of Cushman and Cheung (Cushman and Cheung, 1971, Biochem. Phamacol. 20:1637-1648). The Cushman/Cheung method is based on the liberation of hippuric acid from hippuryl-L-histidyl-L-Leucine, catalyzed by ACE. The ACE inhibiting percentage was calculated by the following equation: Inhibiting percentage=(A−B)/(A−C)×100%, where A is the absorbance at 228 nm of hippuric acid free of sample, B is the absorbance at 228 nm of hippuric acid with sample, and C is the absorbance at 228 nm of hippuric acid free of ACE and sample.
[0055] Antioxidant Activity of WSE from Milk Fermented with L. lactis Strains NRRL B-50571 or NRRL B-50572
[0056] Water soluble extracts (<3 KDa) obtained after fermenting milk with L. lactis strains NRRL B-50571 or NRRL B-50572 presented high TROLOX (F. HOFFMAN-LAROCHE, LTD, Basel, Switzerland) equivalent antioxidant capacity (TEAC) (>1500 μM) as determined by the ABTS method (Re et al., 1999, Free Radical Bio. Med. 26(9):1231-1237). Thus, fermented milk by these specific L. lactis strains present the additional physiological effects of reducing the detrimental effects of oxidation without the need for the use of natural antioxidants such as vitamin E or vitamin C, which are extremely fat or water soluble, so their applications are limited and cannot be maintained stable for long periods of time. On the other hand, the safety of synthetic antioxidants such as butylhydroxyanisol (BHA) and butylhydroxytoluene (BHT) has become questioned and they are oil soluble, thus not useful for their use in aqueous systems. Due to the importance in preventing oxidation in biological systems and to improve stability of food products subject to oxidation, the discovery of WSE obtained from the fermentation of milk with specific L. lactis strains with good antioxidant properties, provides a new alternative for new commercial functional fermented dairy foods.
[0057] Isolation of ACEI Peptide Fractions by Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC) and Identification by Tandem Mass Spectrometry
[0058] Peptide profiles from WSE were obtained by RP-HPLC. Separation was carried out with a Discovery-C 18 (250 mm×4.6 mm, 5 μm particle size, 180 Å pore size) column from SUPELCO ANALYTICAL (Bellefonte, Pa., USA) with a solvent flow rate of 0.25 mL min −1 . Once the column was equilibrated with solvent A (0.04% Trifluoroacetic acid (TFA) in water), 20 μL of the WSE were injected. Peptides were eluted with an increasing gradient of solvent B (0.03% TFA in acetonitrile) from 0% to 45% in solvent A, during 60 min. Peptide profiles monitored at 214 nm and 280 nm were collected from five chromatographic runs and freeze-dried to be subjected to ACEI activity analysis and IC 50 determination ( FIGS. 1 and 2 ). FIG. 1A shows WSE peptide fraction profiles produced by specific wild L. lactis strains monitored at 214 nm absorbance. Unfermented milk was used as a control. The area under the curve of each peptide profile was evaluated as an indirect measure of proteolysis. Results showed significant differences (P<0.01) between fermented milk peptide profiles and the control. On the other hand, the peptide profiles obtained from milk fermented with different strains of L. lactis were similar. The first peak eluted after 12 min in all samples. The largest concentration of peptides eluted between 12 and 25 min when the concentration of acetonitrile was between 9-13.5%, which may be related to the relatively hydrophobic nature of the eluted peptide. On the other hand, when WSE were monitored at 280 nm, only three peaks eluted between 16 and 20 min ( FIG. 1B ). These peptides may have ACEI activity since they were of aromatic nature.
[0059] Peptide chromatographic profiles were divided into 6 fractions and collected for further evaluation. Peptide profiles obtained at 214 nm were divided into F1-F5 fractions ( FIG. 1A ), meanwhile peptide profiles obtained at 280 nm corresponded to F6 ( FIG. 1B ). Peptide fractions F1-F6 showed remarkable IC 50 values ranging from 0.034±0.002 to 0.61±0.19 μg mL −1 ( FIG. 2 ). Results did not show significant difference (P>0.01) between all peptide fractions IC 50 . However, the peptide fractions IC 50 values obtained from milk fermented by L. lactis strains NRRL B-50571 (0.076±0.004 and 0.034±0.002 μg mL −1 for F1 and F6, respectively) and milk fermented by L. lactis NRRL B-50572 (0.041±0.003 and 0.084±0.003 pg mL −1 for F1 and F2, respectively) showed the lowest values ( FIG. 2 ). Therefore, the results suggest that the specific wild L. lactis strains presented have remarkable ACE-Inhibitory activity. Both strains did not present a significant difference (P>0.01) in IC 50 values and proteolysis, which are related to ACE-Inhibitory activity.
[0060] Peptide identification was performed by analyzing the different fractions by mass spectrometry using a 1100 Series LC/MSD Trap from Agilent equipped with an electro spray ionization source (LC-ESI-MS). The nano column was a C 18 -300 (150 mm×0.75 μm, 3.5 μm; (AGILENT TECHNOLOGIES, INC., Palo Alto, Calif., USA). The sample injection volume was 1 μL. Solvent A was a mixture of water-acetonitrile-formic acid (10:90:0.1, v/v/v) and solvent B contained water-acetonitrile-formic acid (97:3:0.1, v/v/v). The gradient was based on the increment of solvent B which was initially set at 3% for 10 min and it took 23 more min to reach 65%. The 0.7 μL min −1 flow rate was directed into the mass spectrometer via an electrospray interface. Nitrogen (99.99%) was used as the nebulizing and drying gas and operated with an estimated helium pressure of 5×10 −3 bar. The needle voltage was set at 4 kV. Mass spectra were acquired over a range of 300-2500 mass/charge (m/z). The signal threshold to perform auto MS n analyses was 30,000. The precursor ions were isolated within a range of 4.0 m/z and fragmented with a voltage ramp from 0.35 to 1.1 V. Peptide sequences were obtained from mass spectrometry data using the Mascot server through the UniProtKB/Swiss-prot database sequences. Table 2 presents the identified sequences of peptides in the six fractions collected from milk fermented by specific L. lactis strains associated to ACEI activity. A typical mass spectrum of the peptide sequence DDQNPH, produced by L. lactis NRRL B-50571 fermented milk is shown in FIG. 3 .
[0061] Antihypertensive Effects of Single-Dose Consumption of Milk Fermented by Specific Lactococcus lactis Strains NRRL B-50571 or NRRL B-50572
[0062] Previous work demonstrated that milk fermented by specific Lactococcus (L.) lactis strains significantly inhibited the activity of angiotensin I-converting enzyme (ACE). However, the relationship between ACEI and the in vivo action had to be tested. Therefore, the antihypertensive and heart rate (HR) lowering effect of milk fermented by specific L. lactis in a murine model was investigated. Spontaneously hypertensive male rats (SHR) (271±14 g) were randomized into four treatment groups: oral administration of milk fermented by L. lactis NRRL B-50571 or L. lactis NRRL B-50572 at 35 or 50 mg protein/kg of body weight (BW). Two more groups were fed with different solutions as controls: a saline solution was the negative control, meanwhile captopril (40 mg/kg BW), a proven ACE inhibitor was the positive control. Blood pressure and heart rate were monitored by the tail cuff method before treatments and 2, 4, 6 and 24 h post oral administration. Results demonstrated that milk fermented by L. lactis NRRL B-50571 as well as milk fermented by L. lactis NRRL B-50572 presented an important systolic (SBP) and diastolic blood pressure (DBP) and HR lowering effect. Thus, milk fermented by specific L. lactis strains present potential benefits in the prevention and treatment of cardiovascular diseases associated to hypertension in humans.
[0063] Samples of specific L. lactis fermented milk (prepared as previously described) for the single dose bioassay were obtained by centrifugation at 20,000×g for 10) min at 0° C. The supernatants were collected and lyophilized with a freeze dryer until used. The experimental protocol was performed with forty-two male spontaneously hypertensive male rats (SHR) (4-5 weeks old, 72±7 g body weight (BW)) obtained from HARLAN LABORATORIES, INC, (Indianapolis, Ind., USA). SHR were weaned for eight weeks and their systolic blood pressure monitored during this period. Rats were randomly housed in pairs per cage at 21±2° C. with 12 h light/dark cycles, 52±6% relative humidity and with ad libitum intake of a standard diet (TEKLAD, Harlan Laboratories, USA) and purified water. SHR (12-13 weeks old, 271±14 g BW) were divided into six groups of seven rats (n=7): Oral administration of saline was the negative control, meanwhile captopril (proven hypotensive drug) (40 mg/kg BW) was the positive control. Animals were weighed before oral administration in order to prepare the corresponding amount of lyophilized whey/kg of animal weight. Lyophilized whey fractions of milk fermented by L. lactis NRRL B-50572 or NRRL B-50571 were dissolved in 0.8 mL of saline. Treatments were NRRL B-50572-3 (35 mg protein/kg BW), NRRL B-50572-5 (50 mg protein/kg BW), NRRL B-50571-3 (35 mg protein/kg BW) and NRRL B-50571-5 (50 mg protein/kg BW).
[0064] Conscious SHR received a single dose through a canula between 8:30 and 9:30 am to eliminate circadian cycles. Animals were restrained in the warming chamber for 20 min at 32° C. to detect pulsations through the caudal artery. Systolic blood pressure (SBP), diastolic blood pressure (DBP) as well as heart rate (HR) were monitored before administration and 2, 4, 6 and 24 h post-administration. Measurements were taken five times using the non-invasive blood pressure system included photoelectric sensor, amplifier, automatic inflation cuff and software (Model 229, IITC LIFE SCIENCE, Woodland Hills, Calif., USA). The animal experimental procedures were done following the guidelines and supervision of the CIAD (Centro de Investigación en Alimentación y Desarrollo), A.C. Committee of Ethics for scientific research.
[0065] SBP changes are shown in FIG. 4 a . Results showed the maximal SBP reductions at 6 h post oral administration. SHR treated with the whey fractions of milk fermented by L. lactis NRRL B-50572-5 and L. lactis NRRL B-50571-3 presented the more relevant decrement of SBP, 16.7±3.5 mm Hg and 17.7±4.0 mm Hg, respectively, although treatments were not significantly different (P<0.05). The maximum decrease at 6 h was observed in animals treated with captopril which was significantly different from the treatments (P<0.05). However, the SBP measurements 24 h post administration showed that SHR treated with the whey fraction of milk fermented by L. lactis NRRL B-50572-5 presented 4.3 mm Hg less than rats that were treated with captopril. These results suggest that L. lactis NRRL B-50572-5 fermented milk may have an important residual blood pressure reducing effect. Moreover, a remarkable 15.3 mm Hg SBP decrement between SHR that received the whey fraction of milk fermented by L. lactis NRRL B-50572-5 and SHR treated with saline was found. Hence, blood pressure measurements suggested an absence of dosage dependent relationship between the protein content of the whey fraction corresponding to milk fermented by L. lactis NRRL B-50571 and its ability to reduce SBP, meanwhile the whey fraction of milk fermented with L. lactis NRRL B-50572 was dosage dependent.
[0066] FIG. 4 b shows the reduction of DBP in SHR caused by the oral administration of the whey fraction of milk fermented by specific L. lactis strains. The highest decrement of DBP was observed at 6 h post oral administration. At the same time, no significant difference was found (P<0.05) when SHR were treated with whey fraction of milk fermented by L. lactis NRRL B-50571 at any protein content or whey fraction of fermented milk L. lactis NRRL B-50572-5. Whey fractions from milk fermented by L. lactis NRRL B-50571 as well as milk fermented with L. lactis NRRL B-50572 presented an important dosage dependent antihypertensive effect through DBP measurements. Although, captopril generated the maximum DBP reduction with each measurement, there was not a significant difference (P<0.05) with the hypotensive effect of the whey fraction of milk fermented by L. lactis NRRL B-50572-5.
[0067] HR reductions at 2, 4, 6 and 24 h of treated SHR are shown in FIG. 4 c . There was not a significant difference (P<0.05) in HR presented by rats administered with whey fractions from milk fermented with L. lactis NRRL B-50572-5 or NRRL B-50571-3 or captopril. As in SBP and DBP, the lowest HR values were found at 6 h post administration of treatments. In fact, SHR treated with the whey fraction L. lactis NRRL B-50571-3 fermented milk, as well as the whey fraction L. lactis NRRL B-50572-5 fermented milk presented the maximal HR decrement, 16.6±9.2 and 16.9±11.5 beats min −1 , respectively. Moreover, a significant (P<0.05) HR decrement (33.4 beats/min) was found in SHR that received the whey fraction from L. lactis NRRL B-50572-5 fermented milk when compared with saline treatment at the end of the 24-h post oral administration.
[0068] Antihypertensive and Hypolipidemic Effects of Long-Term Consumption of Milk Fermented by Specific Lactococcus lactis Strains NRRL B-50571 or NRRL B-50572
[0069] It was demonstrated that the fractions of these fermented milks, showed an acute antihypertensive and heart rate (HR)-lowering effect in spontaneously hypertensive rats after receiving a single dose. Thus, the antihypertensive and hypolipidemic effects of long-term consumption of fermented milk with specific L. lactis strains were also tested in SHR.
[0070] SHR were feed ad libitum with milk fermented by L. lactis NRRL B-50571, L. lactis NRRL B-50572, captopril (40 mg/ kg body weight) or purified water for four weeks. Results suggested that L. lactis fermented milks presented a significant (p<0.05) blood pressure-lowering effect. There was not a significant difference (p>0.05) among milk fermented by L. lactis NRRL B-50571 and captopril by the second and third week of treatment. Additionally, milk fermented by L. lactis strains modified SHR lipid profiles. Milk fermented by L. lactis NRRL B-50571 and B-50572 was able to reduce plasma low-density lipoprotein (LDL) cholesterol by 55.4±3 mg/dL and 66.3±4 mg/dL, respectively. Thus, milk fermented by L. lactis strains may be a coadjuvant in the reduction of hypertension and hyperlipidemia and may be used as a functional food for better cardiovascular health.
[0071] Samples of specific L. lactis fermented milk (prepared as previously described) were prepared by heating at 98° C. for 10 min to inactive proteases and L. lactis strains. Subsequently, samples were frozen at −20° C. All fermented milk samples were daily unfrozen and homogenized (for 20 minutes before use. Thirty-two male SHR were obtained from Harlan Laboratories, Inc., (Indianapolis, Ill., USA). The rats were randomly housed in pairs per cage at 21±2° C. with 12 h light/dark cycles, 52±6% relative humidity and with ad libitum intake of a standard diet (TEKLAD, Harlan Laboratories, USA) during the experiment. SHR (27-28 weeks old and 355±24 g weight) were divided into four groups of eight rats (n=8): purified water (negative control), captopril (proven hypotensive drug, positive control) (40 mg/kg body weight (BW), milk fermented by L. lactis NRRL B-50571 and milk fermented by L. lactis NRRL 50572. All SHR had free access to each treatment during three weeks as part of the protocol. Half of the animals were sacrificed at the end of that period. The rest of the SHR only received purified water during one more week before being sacrificed. A research animal protocol was followed according to the guidelines established by the institutional (CIAD, A.C.) Ethics Committee. The lowering blood pressure effect of milk fermented by specific L. lactis strains on SHR was monitored through time. Animals were deposited in restrainers in the warming chamber for 20 min at 32° C. to detect pulsations through the caudal artery. Systolic (SBP) and diastolic (DBP) blood pressures were measured five times on each conscious animal before treatments and every week during the experiment. Measurements were obtained using the tail-cuff method between 9 and 12 h to eliminate circadian cycles. The non-invasive blood pressure system used in this experiment included a photoelectric sensor, an amplifier, an automatic inflation cuff and software (Model 229, IITC Life Science Inc., Woodland Hills, Calif., USA).
[0072] The hypolipidemic activity of milk fermented by specific L. lactis strains were also evaluated in SHR. Blood samples were collected under anesthesia by cardiac puncture in tubes with heparin (SARSTEDT AG & CO., Nümbrecht, Germany). Subsequently, samples were centrifuged at 2,500 rpm, 4° C. for 10 min to obtain the plasma and they were frozen at −20° C. for further studies. Triglycerides (TG), total cholesterol (TC), and high-density lipoprotein cholesterol (HDL-C) levels in plasma were determined by a commercial kit (RANDOX LABORATORIES, Kearneysville, W. Va., USA), while low density lipoprotein cholesterol (LDL-C) was calculated as the difference between TC and HDL-C according to specifications.
[0073] Both L. lactis fermented milks were able to reduce blood pressure during the experiment ( FIGS. 5 and 6 ). Results did not show significant difference (P>0.05) between systolic blood pressure (SBP) measurements in the first week ( FIG. 5 ). However, by the second week, the SBP reduction in SHR that received milk fermented by L. lactis NRRL B-50571 (−20.2±3.8 mm Hg) was not statistically different (P>0.05) from those that received captopril (−30.1±7.1 mm Hg). In fact, by the second and third week, SHR treated with captopril or milks fermented by L. lactis NRRL B-50571 or B-50572 presented a marked lowering-effect on SBP. By the fourth week of treatment, milk fermented by L. lactis NRRL B-50571 was able to reduce SBP by 23.3±1.8 mm Hg, meanwhile captopril reduced SBP by 28.1±1.8 mm Hg.
[0074] As it is observed in FIG. 5 , the SBP lowering-effect in SHR treated with milk fermented by L. lactis NRRL B-50571 increases with time. Indeed, the maximal SBP reduction was found by the fourth week, even though animals drank only water in the last week. Thus, these results suggest a residual SBP lowering-effect after cessation of the treatment. Milk fermented containing antihypertensive peptides administered for long periods may extend their bioactivity even after cessation of the treatment.
[0075] SHR treated with milk fermented by L. lactis NRRL B-50571 and B-50572 presented DBP lowering-effect during the experiment ( FIG. 6 ). As in SBP, the first week, DBP measurements were not significantly different (P>0.05) between treatments. However, by the second week, milk fermented by L. lactis NRRL B-50571 was able to reduce DBP by 24.5±6.6 mm Hg. Meanwhile, captopril reduced DBP by 38.4±8.5 mm Hg. Furthermore, by the third experimental week, the DBP lowering-effect was not significantly different (P>0.05) between SHR treated with captopril and milk fermented by L. lactis NRRL B-50571 or B-50572. The most important DBP reduction (49.8±3.5 mm Hg) was observed by the fourth week of treatment in SHR that received milk fermented by L. lactis NRRL B-50571.
[0076] In addition, fermented milks were able to modify SHR lipid profiles by the third week of treatment. SHR that received milk fermented by L. lactis NRRL B-50571 or B-50572 presented 55.4±3 mg/dL and 66.2±4 mg/dL reduction of low-density lipoprotein cholesterol (LDL-C), respectively, when compared to SHR administered purified water ( FIG. 7 ). Similarly, results showed that milk fermented by L. lactis strains reduced HDL-C significantly (P<0.05) in treated SHR ( FIG. 8 ).
[0077] Plasma triglyceride (TG) content was also decreased by 34.7±3.7 mg/dL in SHR treated with L. lactis NRRL B-50572 fermented milk when compared to purified water ( FIG. 9 ). Additionally, plasma total cholesterol (TC) content was also reduced in treated SHR, although differences were not significantly different. Milk fermented by L. lactis NRRL B-50572 or B-50571 was able to reduce TC by 10±3.2 mg/dL and 8.6±2.4 mg/dL, respectively ( FIG. 10 ).
[0078] The cholesterol lowering effect may be attributed to cholesterol removal by the L. lactis strains per se, however, this remains to be determined. On the other hand, the lowering effect on LDL-C observed in this study may also be attributed to the ingestion by SHR of dairy protein and/or peptides produced by L. lactis , including those from whey protein.
[0079] The use of milk fermented by specific lactic acid bacteria may be considered as a coadjuvant for the improvement of cardiovascular health. To the best of our knowledge, this is the first in vivo study that showed the antihypertensive and hypolipidemic effects of long-term consumption of fermented milk with specific L. lactis strains. Thus, dairy products fermented with L. lactis strains, NRRL B-50571 and NRRL B-50572 may be used as functional foods with potential benefits for cardiovascular health.
[0000]
TABLE 1
Primers used for the identification of
Lactococcus lactis strains
Primer
Sequence
PALA 4
(5′-CTTCAACAGACAAGTCC-3′), SEQ ID NO: 22
PALA 14
(5′-GATAAATGATTCCAAGC-3′), SEQ ID NO: 23
[0000]
TABLE 2
Identification of peptides sequences obtained from milk fermented
by specific wild L. lactis strains associated to ACEI activity.
Experimental
Theoretical
Sequence
Sample a
Mass
Mass
ID.
Protein fragment
Sequence
NRRL B-
723.9
724.3
1
α-La (f63-68)
DDQNPH
50571
1032.8
1033.5
2
α-La (f82-89)
LDDDLTDDI
F1
698.6
698.3
3
κ-CN (f35-40)
YPSYGL
1479.0
1479.7
4
κ-CN (f98-110)
HPHPHLSFMAIPP
1035.7
1035.5
5
α-La (f55-62)
YDTQAIVQ
1386.8
1387.7
6
α-La (f100-111)
DDDLTDDIMCV
585.9
585.2
7
κ-CN (f35-39)
YPSYG
F2
505.9
585.2
8
α S1 -CN (f62-66)
AESIS
F3
830.1
830.5
9
β-CN (f22-28)
SITRINK
1051.4
1051.5
10
α S1 -CN (f80-88)
HIQKEDVPS
904.1
904.5
11
κ-CN (f161-169)
TVQVTSTAV
F4
904.3
904.5
11
κ-CN (f161-169)
TVQVTSTAV
1038.4
1038.6
12
α S2 -CN (f115-124)
NAVPITPTLN
977.1
977.6
13
β-CN (f69-77)
SLPQNIPPL
F5
1716.9
1717.0
14
β-CN (f194-209)
QEPVLGPVRGPFPIIV
1150.4
1150.7
15
β-CN (f199-209)
GPVRGPFPIIV
977.2
977.6
13
β-CN (f69-77)
SLPQNIPPL
1094.4
1094.6
16
κ-CN (f25-33)
YIPIQYVLS
F6
904.4
904.5
11
κ-CN (f161-169)
TVQVTSTAV
1356.7
1357.7
17
κ-CN (f157-169)
PEINTVQVTSTAV
591.8
592.3
18
Serotransferrin (f448-453)
GYLAVA
NRRL B-
1371.53
1372.7
19
β-CN (f129-140)
DVENLHLPLPLL
50572
698.6
698.3
3
β-CN (f35-40)
YPSYGL
F1
549.8
550.2
20
β-Lg (f60-64)
ENGEC
F2
904.2
904.5
11
κ-CN (f161-169)
TVQVTSTAV
F3
904.2
904.5
11
κ-CN (f161-169)
TVQVTSTAV
F5
1150.5
1150.7
15
β-CN (f199-209)
GPVRGPFPIIV
F6
922.4
922.4
21
α-La (f86-93)
TDDIMCVK
a = Fractions collected from milk fermented by L. lactis NRRL B-50571 and NRRL B-50572.
[0080] In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense. | New Lactococcus lactis strains, NRRL B-50571 and NRRL B-50572, and a bacterial preparation containing the same, have the ability to produce bioactive peptides that reduce blood pressure, lower LDL-cholesterol (bad cholesterol) and present antioxidant properties for better cardiovascular health. These biologically active peptides may be produced within the food for the production of a food product, such as a functional food, or they may be produced from protein sources and subsequently added to a food as part of the formulation or as part of a food supplement or a pharmaceutical preparation. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a series of surface active polyether biguanide salts. The invention also relates to a series of water solutions of surface active polyether biguanide salts.
2. Description of the Prior Art
The term surfactant refers to substances which lower liquid-liquid, liquid-solid or liquid-gas interfacial tension. Surfactant solutions used by themselves or in conjunction with cleaning adjuvants such as additives or builders are widely used to wet surfaces, remove soil, penetrate porous materials, disperse particles, emulsify oils and greases, etc., dependent upon the particular characteristics of the surfactant or surfactants used.
Desirably surfactants are inexpensive, light colored materials which function at low concentration levels in aqueous solutions and which can be produced in good yield from readily available low cost starting materials, free from deleterious contaminants, preferably as easily handled, free-flowing liquids or powders.
For many applications, such as heavy duty industrial applications for metal scouring and dishwasher detergent compositions, the compositions necessarily include highly alkaline materials such as alkali metal hydroxides, alkoxides and phosphates. In the aqueous media that these detergents function, the pH of the cleaning solution frequently will be from 10 to 13. For this reason a prerequisite of heavy duty detergency compositions is stability at elevated pH's in aqueous solutions.
It has been found, surprisingly, that certain polyether biguanide epoxy curative agents described in U.S. Pat. No. 4,403,078 display surface activity in water solution.
SUMMARY OF THE INVENTION
This invention relates to a series of polyether biguanide salts which find use as detergents. The composition of matter of the present invention is characterized by the general formula: ##STR2## wherein:
y ranges from 0 to 6,
z ranges from 2 to 50,
A is an anion selected from the group consisting of chloride, bromide, sulfate, bisulfate, phosphate, dihydrogen phosphate, and hydrogen phosphate,
n is the valence of the anion and
R 1 is selected from the group consisting of alkyl and alkylphenyl each of 1 to 24 carbon atoms; with the proviso that when z ranges from 2 to 14, R 1 is limited to 8 to 24 carbon atoms and when z ranges from 15 to 50, R 1 is limited to 1 to 7 carbon atoms.
These compositions of matter have a variety of uses. These uses include hair conditioning agents, foam boosters and fabric softeners.
DETAILED DESCRIPTION OF THE INVENTION
Polyether biguanide salts are the surfactants of the present invention. These surfactants are prepared essentially in two steps. A method is fully described in U.S. Pat. No. 3,909,200 which is incorporated herein in its entirety by reference.
In the first step a salt is prepared from a polyoxyalkylene momoamine of the formula:
R.sub.1 [OCH.sub.2 CH.sub.2 ].sub.y [OCH.sub.2 CH(CH.sub.3)].sub.z NH.sub.2
wherein:
y ranges from 0 to 6,
z ranges from 2 to 50, and
R 1 is selected from the group consisting of alkyl and alkylphenyl each of 1 to 24 carbon atoms; with the proviso that when z ranges from 2 to 14, R 1 is limited to 8 to 24 carbon atoms and when z ranges from 15 to 50, R 1 is limited to 1 to 7 carbon atoms. When R 1 is alkyl the alkyl is preferably normal. When R 1 is alkylphenyl the alkyl is preferably branched.
In the alternative, in solutions of the present invention, a polyoxypropylenediamine may be utilized as a starting material. This diamine is of the general formula:
H.sub.2 NCH(CH.sub.3)CH.sub.2 [OCH.sub.2 CH(CH.sub.3)].sub.x NH.sub.2
wherein:
x ranges from 15 to 90, preferably 30 to 40.
As stated, a salt is prepared from the monoamine or diamine as previously defined with a desired acid of an appropriate ratio of one equivalent of acid for every amine functionality, to produce an amine salt.
In a second step, the salt is treated with a slight molar excess (based on amine groups present) of dicyandiamide (cyanoguanidine) and heated in the presence or absence of added solvent at about 100° C. to 200° C. (preferably 150° C.) for 1 to 10 hours until the biguanide salt is formed.
Inorganic salts such as HCl or H 2 SO 4 are preferred for this reaction. It has been found to be necessary to neutralize each amine functionality with an equivalent of acid for the biguanide formation to take place. Excess acid can be employed but is not desirable. Less than one mole of acid/mole of amine can be utilized only if a di- or tri-basic acid is used.
The compositions of matter are then diluted to the desired strength. It has been found that the most cost effective dilution is 0.01 wt% to 20 wt% preferably 0.1 wt% to 5 wt% with a water diluent. In this regard, the present invention is:
An aqueous solution comprising:
A. 0.01 wt% to 20 wt% preferably 0.1 wt% to 5 wt% of a composition of matter of the general formula: ##STR3## wherein:
y ranges from 0 to 6,
z ranges from 2 to 50,
A is an anion selected from the group consisting of chloride, bromide, sulfate, bisulfate, phosphate, dihydrogen phosphate, and hydrogen phosphate,
n is the valence of the anion, and
R 1 is selected from the group consisting of alkyl and alkylphenyl each of 1 to 24 carbon atoms with the proviso that when z ranges from 2 to 14, R 1 is limited to 8 to 24 carbon atoms and when z ranges from 15 to 50, R 1 is limited to 1 to 7 carbon atoms; and
B. water.
This invention is also an aqueous solution comprising:
A. 0.01 wt% to 20 wt% preferably 0.1 wt% to 5 wt% of a composition of matter of the general formula: ##EQU1## wherein:
A is an anion selected from the group consisting of chloride, bromide, sulfate, bisulfate, phosphate, dihydrogen phosphate, and hydrogen phosphate,
n is the valence of the anion,
R 2 is a polyxoypropylene radical of the formula:
--CH(CH.sub.3)CH.sub.2 [OCH.sub.2 CH(CH.sub.3)].sub.x --
wherein:
x ranges from 15 to 90 preferably 30 to 40; and
B. water.
The polyether biguanide salts exhibit long lasting surfactant properties in aqueous solution in concentrations ranging from 0.01 wt% and higher depending upon the mode of application. The minimal concentration of ethoxylated product usually employed is about 0.01 wt% while the upper concentration, which is limited almost entirely by cost, for all but special purposes seldom exceeds 20 wt%. Usually the range of concentration is between about 0.1 wt% to 5 wt% with the residuum being detergent adjuvants described below. In all instances the lower or minimal concentration (0.01% by weight) is referred to as an "effective amount" of surfactant. When these products are employed as detergents they ordinarily are present in at least the minimal concentrations disclosed accompanied by one or more of the following classes of materials which are generically referred to as detergent adjuvants:
1. Inorganic salts, acids and bases. These are usually referred to as "builders." These salts usually comprise alkalies, phosphates and silicates of the alkali metals as well as their neutral soluble salts. These materials constitute from about 40 to 80 weight percent of the composition in which they are employed.
2. Organic builders or additives--These are substances which contribute to characteristics such as detergency, foaming power, emulsifying power or soil suspending effect. Typical organic builders include sodium carboxymethyl cellulose, sequestering agents such as ethylenediaminetetraacetic acid and the fatty monoethanolamides, etc.
3. Special purpose additives--These include solubilizing additives such as lower alcohols, glycols and glycol ethers, bleaches or brighteners of various structures which share in common that they are dyestuffs and they do not absorb or reflect light in the visible range of the spectrum.
______________________________________DETERGENT FORMULATIONS______________________________________A. Dry cleaning compositionParts by wt. Components______________________________________5 SURFONIC ® N-40 (average 4 molar ethoxylate of nonylphenol)5 Product Example E60 Dry cleaning solvent30 WaterB. Disinfectant and Detergent CompositionParts by wt. Component______________________________________5 Product of Example C5 EDTA88 10% Hydrochloric Acid2 SURFONIC ® N-95 (average 9.5 molar ethoxylate of nonylphenol)C. ShampooParts by wt. Component______________________________________5 Product of Example A5 Cocoamide DEA20 Sodium lauryl sulfate70 Water______________________________________
In regard to actual use of the composition of matter of the present invention particularly in water base solutions, it has been found that a favorable cost to benefit ratio is achieved when R 1 is a normal alkyl of from 9-18 carbon atoms or R 1 is alkylphenyl selected from the group consisting of nonylphenyl, decylphenyl, undecylphenyl and dodecylphenyl.
Further in regard to actual use, criticality has been found in the parameter x. Surface activity is found in the range of x from 15 to 90. Excellent surfactant properties are demonstrated when x ranges from 30 to 40 as shown in Example F.
This invention is better shown by way of example.
EXAMPLE A
(1) A one-liter resin flask equipped with mechanical stirrer, thermometer and nitrogen inlet was charged with 618 grams of JEFFAMINE® D-2000 and 61 grams concentrated hydrochloric acid. The mixture was vacuum stripped at 100° C. to remove all traces of water. Dicyandiamide (65.2 grams; 1.25 equivalents) was added and the mixture was stirred under nitrogen atmosphere for seven hours to obtain the desired bis(biguanide) hydrochloride salt; identified by total amine analysis and infrared spectrum as: ##STR4## wherein R 2 is:
--CH(CH.sub.3)CH.sub.2 [OCH.sub.2 CH(CH.sub.3)].sub.33.1 --
(2) One hundred grams of the hydrochloride salt of D-2000 bis(biguanide), prepared according to A (1), was treated with 6.8 g 50% aqueous sodium hydroxide solution and heated with mechanical stirring at 100° C. for one hour. The mixture was vacuum stripped to remove water and filtered to remove sodium chloride. The free biguanide filtrate contained only 0.43% Cl and was insoluble (1 wt% would not dissolve in water at 25° C.).
JEFFAMINE® D-2000 is the diterminal diamine of polyoxypropylene of molecular weight 2000 of the general formula:
H.sub.2 NCH(CH.sub.3)CH.sub.2 [OCH.sub.2 CH(CH.sub.3)].sub.33.1 NH.sub.2
EXAMPLE B
Charged 1-liter flask with 657 grams JEFFAMINE® M-1000 and added 64.8 g concentrated hydrochloric acid. Water was removed under reduced pressure at 100° C., system was purged with nitrogen, and 69 g (1.25 equiv.) dicyandiamide was added with mechanical stirring. The mixture was heated to 150° C. and stirred under nitrogen atmosphere for an additional 6 hours. Product was identified as the desired biguanide hydrochloride salt by elemental and spectral analyses. Structure was: ##STR5##
JEFFAMINE® M-1000 is a monoamine of molecular weight 1000 of the general formula:
H.sub.2 N[CH(CH.sub.3)CH.sub.2 O].sub.2.6 --[CH.sub.2 CH.sub.2 O].sub.18.6 --CH.sub.3
EXAMPLE C
Method of Example B was used with 278 g JEFFAMINE® M-300, 100 g conc. HCl, and 105 g dicyandiamide.
Product was identified as the desired biguanide hydrochloride salt by elemental and spectral analysis as: ##STR6##
JEFFAMINE® M-300 is a monoamine of the general formula:
CH.sub.3 (CH.sub.2).sub.9 OCH.sub.2 CH(CH.sub.3)OCH.sub.2 CH(CH.sub.3)--NH.sub.2
EXAMPLE D
The method of Example B was used with 600 grams JEFFAMINE® M-600, 100 grams concentrated HCl and 205 grams dicyandiamide.
Product was identified as the desired biguanide hydrochloride salt by elemental and spectral analysis as: ##STR7##
JEFFAMINE® M-600 is a monoamine of molecular weight 600 of the general formula:
CH.sub.3 OCH.sub.2 CH.sub.2 [OCH.sub.2 CH(CH.sub.3)].sub.9 NH.sub.2
EXAMPLE E
Method of Example B was used with 78 g dicyandiamide, 74.5 g conc. HCl, and ##STR8##
Product was identified as the desired biguanide hydrochloride salt by elemental and spectral analysis as: ##STR9##
EXAMPLE F
The surface active properties of water solutions of the products of Examples A, B, C, D and E are reported in Table 1. The surfactant properties of Examples A, C and E are good to excellent, while those of Examples B and D which are outside the scope of the present invention are weak. Criticality has been found in the ratio of the amount of propylene oxide to the size of the terminal alkyl or alkylaryl group. When this terminal alkyl or alkylaryl group is 1 to 7 carbon atoms, the amount of propylene oxide must be increased to 15 to 50 molecules per surfactant molecule to reduce water solubility and thereby increase surface activity. When this group is 8 carbon atoms or greater, the amount of propylene oxide must be reduced 2 to 14 molecules per surfactant molecule to increase water solubility (decrease oil solubility) and thereby increase surface activity. Further, ethylene oxide is added for water solubility in an amount of 0 to 6 molecules per surfactant molecule to balance the effect of propylene oxide and thereby give the molecule its characteristic surface activity. This discovered criticality is expressed as defined herein and in the claims. The wetting ability of the surfactants of Examples A, C and E is somewhat low due to their cationic nature. The good surfactant effectiveness is due to the hydrophobic portion of the biguanide surfactant.
TABLE 1__________________________________________________________________________Surface-Active Properties of Bis(biguanides) and Biguanides Interfacial Ross-Miles Foam Height,Surface Tension Tension mm (120° F.)Product of dynes/cm dynes/cm 0.1% 1.0% Draves Wetting, sec. (0.1%)Example 0.1% 1.0% 0.1% 1.0% 0 5 min 0 5 min 1.5 g hook 3 g hook__________________________________________________________________________A 36.4 34.2 6.2 3.2 74 16 135 22 -- 39B 57.1 46.3 25.1 25.4 -- -- -- -- -- --C 29.6 26.5 1.5 1.6 126 85 -- -- 139 49D 46.3 41.4 16.3 12.2 0 0 -- -- -- >180E 29.5 28.6 1.2 1.2 124 80 149 115 -- --__________________________________________________________________________
The principle of the invention and the best mode contemplated for applying that principle have been described. It is to be understood that the foregoing is illustrative only and that other means and techniques can be employed without departing from the true scope of the invention defined in the following claims: | Polyether biguanide salts of the formula: ##STR1## wherein: y ranges from 0 to 6,
z ranges from 2 to 7,
A is an anion selected from the group consisting of chloride, bromide, sulfate, bisulfate, phosphate, dihydrogen phosphate and hydrogen phosphate,
n is the valence of the anion, and
R 1 is an alkyl of 9 to 18 carbon atoms or alkylphenyl of 15 to 18 carbon atoms, are diluted in water solution. In a preferred embodiment, R 1 is nonylphenyl.
These salts are surface active agents used as hair conditioning agents, foam boosters, corrosion inhibitors, ore flotation agents, fabric softeners or germicides, etc. | 0 |
This application is related to co-pending patent application Ser. No. 09/052,909, filed Mar. 31, 1998, entitled “License Plate Lock”, the disclosure of which is hereby referred to and incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates in general to a locking means for locking license plate attachment bolts and in particular to a license plate attachment means having a locking means for preventing removal of either the license plate or the renewal sticker which may be affixed to the license plate in either of four locations. The locking means includes a cylinder lock with all functioning lock components, i.e., both the lock insertion projection and the insertion projection receiving trench/key way being hidden from observation by any viewer.
BACKGROUND OF THE INVENTION
A description of the related art is discussed in co-pending patent application Ser. No. 09/002,062, filed Dec. 31, 1997, entitled “Theft Proof License Plate Apparatus, which is hereby referred to and incorporated herein, and this same description is applicable herein. Whereas the license plate locking devise disclosed in said co-pending patent application functions very effectively for its intended purpose, the license plate locking device disclosed therein does have the following limitations:
a) The lock hasp, although hidden by a protective enclosure is readily apparent and if a criminal was motivated, there is the possibility that the criminal could use some powered cutting means that would cut through both the lock hasp and its protective enclosure.
b) the lock hasp and its protective enclosure, while positioned such that they are pleasing to the eye of the viewer or user of the license plate lock, they are somewhat bulky and do not present as clean a look as a more simplified locking mechanism that would accomplish the same theft prevention function.
c) The lock hasp design does not allow for an automatic ‘snap’ locking action, such that the operator could lock the device with one quick insertion by hand without having to unlock or open the lock prior to inserting the lock hasp and locking it.
Accordingly, it would be desirable if there were a license plate locking device that had both the lock insertion projection and the insertion projection receiving trench/key way being hidden from observation by any viewer.
Likewise it would be desirable if a renewal sticker theft prevention window locking device would function so as to be applicable for license plates which display such renewal stickers in any corner of the license plates. It would further be desirable if the license plate locking means if the license plate locking device/means uses the existing license plate screws/bolts for attachment.
It would further be desirable if the lock mechanism was capable of completing the locking function with one ‘snap’ locking action, such that the operator could lock the device with one quick insertion by hand without having to unlock or open the lock prior to locking it.
SUMMARY OF THE INVENTION
Briefly, the present invention is a locking device having a renewal sticker theft prevention window locking device that is applicable for license plates which display such renewal stickers in any corner of the license plates. The license plate locking means constructed according to the teachings of the invention uses a cylinder lock that has a flat sided cylindrical bar that cooperates with a grove or trench disposed in a second horizontal bar that extends between the license plate attachment screws so as to retain or lock the second horizontal bar by rigidly interfering with any movement of the second horizontal bar. The license plate locking means of the license plate locking device/means does use the existing license plate screws/bolts for attachment. The license plate attachment screw cylinders receive the existing license plate attachment screws and cooperates with a locking device to prevent removal of the license plate attachment screws.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be understood and further advantages and uses thereof more readily apparent, when considered in view of the following detailed description of the exemplary embodiments, taken with the accompanying drawings, in which:
FIG. 1 is an elevational view of the license plate locking means constructed according to the teachings of the invention illustrating how a grooved rod enters a hollow cylindrical license plate bolt/screw cover and engages with a cylindrical locking mechanism;
FIG. 2 is a detail isometric view of the hollow cylindrical license plate bolt/screw cover of FIG. 1, constructed according to the teachings of the invention;
FIG. 3 is a detail isometric view of the cylindrical locking mechanism of FIG. 1, constructed according to the teachings of the invention;
FIG. 4 is a detail view of the working elements of the cylindrical locking mechanism of FIG. 3;
FIG. 4 a is a detail view of another alternate set of the working elements of the cylindrical locking mechanism of FIG. 3;
FIG. 5 is a top view of the locking plate locking means of FIG. 1 illustrating the grooved rod passing through the hollow cylindrical license plate bolt cover and being retained in the locked position within the cylindrical locking mechanism of FIG. 1 . FIG. 5 also illustrates how the grooved rod passes through an additional hollow cylindrical license plate bolt cover on the opposite side, which bolt cover is mounted through a sticker tab cover, thereby protecting a license plate sticker tab from theft;
FIG. 6 is an isometric view of a plate bolt cover that allows the sticker tab cover to be located over any of each of the four corner areas of a license plate where a sticker tab may alternately be located in various States;
FIG. 7 is an elevational view of the alternate sticker tab cover and license plate bolt cover of FIG. 6 illustrating the alternate sticker tab cover and license plate bolt cover affixed to and locking a license plate to a car body;
FIG. 8 is a top elevational view of the license plate locking means constructed according to the teachings of the invention illustrating the use of the alternate sticker tab cover and license plate bolt cover of FIG. 6 that allows the sticker tab cover to be located over any of each of the four corner areas of a license plate where a sticker tab may alternately be located in various States;
FIG. 9 is a front plan view of the license plate locking means constructed according to the teachings of the invention illustrating the use of the alternate sticker tab cover and license plate bolt cover that allows the sticker tab cover to be located over any of each of the four corner areas of a license plate where a sticker tab may alternately be located in various States; and
FIG. 10 is an elevational view of an alternate license plate bolt cylindrical locking device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and to FIG. 1 in particular there is shown an elevational view of the license plate locking means 10 constructed according to the teachings of the invention illustrating how the grooved rod 12 enters the left hollow cylindrical license plate bolt/screw cover 14 and engages with a cylindrical locking mechanism 16 . Grooved rod 12 enters bolt/screw cover 14 at rod opening 22 and enters cylindrical locking mechanism 16 through rod opening 24 . Grooved rod 12 is captured within cylindrical locking mechanism by rotating projection means 26 which will be described later with to reference to FIGS. 4 and 4A. Grooved rod 12 is repeatably slidable through rod openings 32 disposed through right hollow cylindrical license plate bolt/screw cover 34 . When grooved rod 12 has been slid through rod openings 32 disposed through right hollow cylindrical license plate bolt/screw cover 34 and inserted through bolt/screw cover 14 at rod opening 22 and enters cylindrical locking mechanism 16 through rod opening 24 and when grooved rod 12 is then captured within cylindrical locking mechanism by rotating projection means 26 , then license plate bolts 36 (which have been previously attached/screwed to captured nuts 38 ), will be blocked from access through left and right bolt/screw covers 14 and 34 respectfully. In this manner the attached license plate will be protected from theft, vandalism etc. When cylindrical locking mechanism 16 is locked by means of key 18 , then access is denied to anyone other than the owner of the vehicle/possessor of the key.
Referring now to FIG. 2 there is shown a detail isometric view of the left hollow cylindrical license plate bolt/screw cover 14 of FIG. 1, constructed according to the teachings of the invention. Bolt/screw cover 14 includes cylindrical sidewall 42 having rod entry opening 22 and bottom plate 44 having license plate bolt hole 46 disposed there through. Referring now back to FIG. 1, similarly, right hollow cylindrical license plate bolt/screw cover 34 is constructed the same, except there are two rod openings 32 disposed therein. It is to be understood that left and right bolt/screw covers 14 and 34 could be reversed/interchanged and the licensed plate locking mechanism 10 would work equally well.
Referring now to FIG. 3, there is shown a detail isometric view of the cylindrical locking mechanism 24 of FIG. 1, constructed according to the teachings of the invention and illustrates how rotating projection means 26 interferes with the passage of grooved rod 12 when it enters through rod opening 24 . Referring now to FIG. 4, there is shown a detail view of the working elements of the cylindrical locking mechanism of FIG. 3, wherein rotating projection means 26 is biased so as to interfere with the passage of grooved rod 12 , such that when grooved rod 12 is forced past rotating projection means 26 , then rotating projection means 26 is biased into grove 50 as illustrated schematically in FIG. 4A, wherein there is shown in FIG. 4A a schematic detail view of the working elements of the cylindrical locking mechanism of FIG. 3, both when the grooved rod 12 is pushing past rotating projection means 26 (in phantom) and when grooved rod 12 has cleared rotating projection means 26 , and rotating projection means 26 is biased by a biasing means, preferably by a spring so as to rotate counterclockwise as shown at arrow 48 so as to enter grove 50 as is well known in the art.
Referring now to FIG. 5 there is shown a top view of the license plate locking means of FIG. 1 illustrating the grooved rod passing through the left hollow cylindrical license plate bolt covers 14 respectfully, and being retained in the locked position within the cylindrical locking mechanism 16 of FIG. 1 . FIG. 5 also illustrates how the grooved rod passes through additional hollow cylindrical license plate bolt cover 34 on the opposite side, which bolt cover is mounted through a sticker tab cover 52 , thereby protecting a license plate sticker tab from theft.
Referring now to FIG. 6 there is shown an isometric view of an alternate sticker tab cover 62 and license plate bolt cover 64 that allows the sticker tab cover to be located over any of each of the four corner areas of a license plate where a sticker tab may alternately be located in various States. Note that bolt cover 64 includes rod openings 66 such that a grooved rod 68 may be slidably passed therethrough so as to prevent access to license plate bolt opening 70 . Sticker tab cover 62 , (which may for example be made out of Lexan Plexiglas and have dimensions of 2″ high×3″ wide×¼″ thick) and license plate bolt cover 64 are rigidly attached to one another by screws 72 .
Referring now to FIG. 7 there is shown an elevational view of the alternate sticker tab cover 62 and license plate bolt cover 64 of FIG. 6 illustrating the alternate sticker tab cover 62 and license plate bolt cover 64 affixed to and locking a license plate to a car body by means of license plate bolt 74 for which access is denied by means of lock rod 76 .
Referring now to FIG. 8 there is shown a top elevational view of the license plate locking means constructed according to the teachings of the invention illustrating the use of the alternate sticker tab cover and license plate bolt cover of FIG. 6 that allows the sticker tab cover to be located over any of each of the four corner areas of a license plate where a sticker tab may alternately be located in various States. Referring now to FIG. 9 there is shown a front plan view of the license plate locking means constructed according to the teachings of the invention illustrating the use of the alternate sticker tab cover and license plate bolt cover that allows the sticker tab cover to be located over any of each of the four corner areas of a license plate where a sticker tab may alternately be located in various States.
Referring now to FIG. 10, there is shown an elevational view of an alternate license plate bolt cylindrical locking device 80 or indeed any bolt/screw cylindrical locking device because locking device 80 can be employed to prevent access to any bolt or screw or indeed any type of fastener. Locking device 80 includes cylinder lock 2 , which is operated by key 1 , and which blocks access to flange 3 , which is inserted into hollow cylindrical bolt cover 4 , all of which mechanism is then inserted through hollow cylinder cover 5 . When a bolt is inserted through flange 3 along centerline 6 at entry 7 , and flange 3 is then inserted into hollow cylindrical bolt cover 4 and cylindrical lock 2 is then locked into hollow cylindrical bolt cover 4 by means of projection 8 being inserted and retained in projection retainer groove 9 , then hollow cylindrical bolt cover 4 will just rotate around flange 3 and never release until cylindrical lock 2 is unlocked by key 1 , thereby preventing access to the secured bolt. | The present invention is a license plate locking device that operates with a cylindrical lock. The license plate locking device has a renewal sticker theft prevention window locking device that is applicable for license plates which display such renewal stickers in any corner of the license plates. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. provisional patent application 62/364,592 filed on Jun. 20, 2016, which is hereby incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to systems and methods for conducting mobile device-based interventions and behavioral research. The systems and methods of the present invention may be used to deliver theory-based behavior interventions and manage scientific research studies through the use of networked peripheral devices. The systems and methods include features like SMS text messaging, VoIP (for video and voice calls), and automated scheduling. These features facilitate structured communication between researchers and study participants or healthcare professionals and relevant populations.
BACKGROUND OF THE INVENTION
[0003] Management of research data sets is a complex endeavor that becomes exponentially more difficult as sample size increases and as additional variables must be tabulated. In the case of studies involving data that must be collected on a constant basis, there is increased pressure to ensure that participant (e.g. patient) data is collected in a rigorous, timely manner and relayed to individuals in charge of the study (e.g. physicians) promptly. While there are basic data aggregation technologies in existence, there are none that combine data aggregation with HIPAA compliance and analytics that allow for participants to input data and physicians to review an analyzed version of that data in real-time as the study is progressing.
[0004] Consequently, there is a need for systems and methods that deliver theory-based behavior interventions and manage scientific research studies through the use of networked peripheral devices.
SUMMARY OF THE INVENTION
[0005] It is therefore an object of the exemplary embodiments disclosed herein to alleviate the disadvantages in the art and provide a data management system that uses networked peripheral devices to aggregate scientific data, quantifies various behavioral and physical characteristics, and identifies behavioral patterns in a participant set.
[0006] It is another object of the invention to have a data management system that calculates correlations between behavioral and physical characteristics and participant performance in the scientific study.
[0007] It is yet another object of the invention to have a data management system that provides real-time quantification of participant behavior, both in relation to the current study set and to historical participant performance.
BRIEF DESCRIPTION OF THE FIGURES
[0008] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
[0009] FIG. 1 is an exemplary embodiment of the eHIP data aggregation and analysis system; and
[0010] FIG. 2 is an exemplary logic flow diagram demonstrating how the system incorporates and analyzes scientific data.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. Several preferred embodiments of the invention are described for illustrative purposes, it being understood that the invention may be embodied in other forms not specifically shown in the drawings.
[0012] Mobile Health (“mHealth”) is the practice of public health and medicine supported by web and mobile devices. Systems that implement mHealth protocols allow for a more streamlined implementation of scientific study and improve the ability of researchers to track data trends. Inventors at the University of Arizona have developed a software platform called eHIP (“eHealth & Intervention Platform”). eHIP is an adaptable “software as a service” platform that provides researchers and healthcare professionals a framework for building web and mobile device-oriented research projects or interventions. It includes communication features (including text, voice, and video messaging systems), data collection, and web-based forms. Features can be modified (or built from scratch) to suit the specific needs of any project.
[0013] eHIP is the product of the University of Arizona Bio Computing Facility. Its development was prompted by the organization's collaborations with entities in the public health, nutrition, psychiatry, nursing, pharmacy, and medical fields. The eHIP platform can be used in public health, by healthcare providers, in research, and in other data-oriented projects that will be readily apparent to one of ordinary skill in the art. The eHIP platform has been adapted and used successfully to build a variety of projects, including Stealth Health (text messages delivered to youth in order to promote physical activity and healthier diets), eLEAS (online psychiatric testing), and Walk Across Arizona (fitness promotion program where participants log exercise data online). The eHIP platform includes features like SMS text messaging, VoIP (for video and voice calls), and automated scheduling. These features facilitate structured communication between researchers and study participants or healthcare professionals and relevant populations.
[0014] eHIP is a software platform optimized for delivering theory-based behavior interventions and managing scientific research studies that utilize mHealth and/or eHealth. This broad and adaptable solution leverages affordable technologies (e.g. cloud based telephony) to engage and retain study subjects in interventions while providing real-time data to investigators. It is currently being used in numerous multipurpose, web- and mobile-based applications to promote a variety of lifestyle behavior changes (smoking cessation, diet and physical activity) in both national, multi-site studies.
[0015] In the sphere of public health, one particular example is the “Healthy is Happy” program, which delivered health-oriented text messages to youths in at-risk populations. Delivering interventions over the Internet using the eHIP platform leads to substantial savings versus in-person delivery. For healthcare providers, the eHIP platform may be used in eLEAS, in which psychiatric testing results and data are delivered electronically. eHIP includes security features that make it HIPAA-compliant, an advantage over prior technologies. Migration of services to an easy-to-use secure online platform embodied by the eHIP platform make healthcare delivery more efficient for practitioners by providing real-time access to patient data and patient performance.
[0016] An example of eHIP's utility in research is the Recaller Project. The eHIP platform allows subjects to upload photos of their meals to researchers via a mobile interface so their dietary intake could be analyzed. Studies that would otherwise be impossible without mobile technology (real-time monitoring of heart rate over long periods of time, for example) or projects that would otherwise require a huge time investment on the behalf of the subjects or researcher (meticulous records kept of caloric intake) become much more achievable by using the eHIP platform. Thus, in general, the eHIP platform makes it possible to collect seemingly any type of data, have it analyzed, and also provide communications. Any data-driven project—regardless of whether it is strictly research, healthcare, or public health-related—may be powered by the eHIP platform. Exemplarily, the eHIP platform could be used in conservation interventions: water usage data could be collected from individuals and analyzed. Individuals who use large amounts of water could then be targeted to receive tips on reducing water usage or provided low-flow shower heads.
[0017] The eHIP platform represents an innovative, flexible, and scalable solution for the deployment and case management of large research and intervention projects including those involving cancer, tobacco cessation, obesity, diabetes, alcoholism, drug abuse, stress management, immunization, sun safety, oral hygiene, medicine adherence, diet, physical activity, really anywhere that behavior modification is sought.
[0018] The eHIP application suite integrates a comprehensive spectrum of web-based technologies including, but not limited to, IP telephony, SMS, MMS, forums, social networking, and email, as well as wearable devices and sensors (e.g. FitBits) for the delivery and collection of health information targeting an increasingly technologically adept subject population. The software tracks all technology “touches” in real-time to include phone calls, text messages, and emails as well as all participation activity of study participants. This allows for immediate evaluation of data quality, as well as personalized feedback to study participants for tailored and specific behavior change for each individual subject. Further, the system allows for the deployment of a standardized protocol using cost-effective and HIPAA-compliant software to the target population regardless of geographic location.
[0019] The eHIP platform therefore has a number of advantages over other technologies. For example, the eHIP platform has already been successfully used to develop research and intervention tools that involve the web or mobile devices, including numerous national and multi-site studies. The platform can also encompass the entirety of the online functionality required by a given project, from consulting and software development to deployment, data analysis, and archival. Moreover, the eHIP platform is modular in nature. It can include many features—data collection, data analysis, intervention delivery—or only a few. Additionally, the data gathered from relevant populations by components of the eHIP platform can be made immediately available for use.
[0020] FIG. 1 is an exemplary embodiment of the data aggregation and analytics system. In the exemplary system 100 , one or more peripheral devices 110 are connected to one or more computers 120 through a network 130 . Examples of peripheral devices 110 include smartphones, tablets, wearable devices such as smartwatches, medical devices such as EKGs and blood pressure monitors, and any other devices that collect patient data that are known in the art. The network 130 may be a wide-area network, like the Internet, or a local area network, like an intranet. Because of the network 130 , the physical location of the peripheral devices 110 and the computers 120 has no effect on the functionality of the hardware and software of the invention. Both implementations are described herein, and unless specified, it is contemplated that the peripheral devices 110 and the computers 120 may be in the same or in different physical locations. Communication between the hardware of the system may be accomplished in numerous known ways, for example using network connectivity components such as a modem or Ethernet adapter. The peripheral devices 110 and the computers 120 will both include or be attached to communication equipment. Communications are contemplated as occurring through industry-standard protocols such as HTTP.
[0021] Each computer 120 is comprised of a central processing unit 122 , a storage medium 124 , a user-input device 126 , and a display 128 . Examples of computers that may be used are: commercially available personal computers, open source computing devices (e.g. Raspberry Pi), commercially available servers, and commercially available portable device (e.g. smartphones, smartwatches, tablets). In one embodiment, each of the peripheral devices 110 and each of the computers 120 of the system have eHIP software related to the system installed on it. In such an embodiment, data related to the patient studies performed are stored locally on the networked computers 120 or alternately, on one or more remote servers 140 that are accessible to any of the networked computers 120 through a network 130 . In alternate embodiments, the eHIP software runs as an application on the peripheral devices 110 .
[0022] FIG. 2 is an exemplary logic flow diagram of the software processes performed using the hardware described in FIG. 1 above. The process begins with step 200 , “Access eHIP and Input Data,” where the patient accesses the eHIP software on his or her peripheral device 110 and inputs responses to behavioral and/or physical characteristics. Behavioral characteristics may include such traits as daily caloric intake, types of food ingested, mental health, drug dosages, locations visited, environment, and others that will be readily apparent to those of ordinary skill in the art. Physical characteristics may include such traits as age, height, weight, blood pressure, cholesterol, glucose concentration, or others that will be readily apparent to one of ordinary skill in the art.
[0023] Behavioral and physical characteristics requiring a response from the patient may be set in advance of a study or added ad-hoc at any time. At step 202 , “eHIP Aggregates and Analyzes Patient Data,” the patient's responses are uploaded to any of the networked computers 120 or the one or more remote servers 140 . At the networked computers 120 or the one or more remote servers 140 , the eHIP software aggregates the patient's data into a searchable profile and analyzes the patient's behavioral and physical characteristics against other patients in the study. At step 204 , “eHIP Performs Scoring and Correlative Analysis,” the eHIP software scores the patient relative to other patients in the study based on each of the behavioral and physical characteristics monitored, as well as creating a composite score of the patient's overall performance. In alternative embodiments, the eHIP software may also apply correlative calculations against historical patient data to determine whether changes in certain behavioral and/or physical characteristics result in a statistically significant change to future health outcomes. The eHIP software may also cluster participants based on behavioral and/or physical characteristics to identify trends related to environment, location, etc.
[0024] At step 206 , “eHIP Outputs Results,” the eHIP software at the networked computers 120 or the one or more remote servers 140 outputs the results of its calculations to the networked computers 120 and/or the peripheral devices 110 . From the networked computers 120 and/or the peripheral devices 110 , a patient or physician can obtain a real-time quantification of the patient's behavior and physical performance, while providing recommendations for improvements to the patient's future performance and identifying potential warning signs in behavioral and/or physical characteristics (or in their composite score) signaling adverse future health outcomes. Based on the calculations, at step 208 , “eHIP Facilitates Communication,” the eHIP software can be used to facilitate SMS text messaging between patients and physicians, VoIP (“Voice over Internet Protocol”) for video and voice calls, and automated scheduling for appointments to discuss participant performance.
[0025] The foregoing description and drawings should be considered as illustrative only of the principles of the invention. The invention is not intended to be limited by the preferred embodiment and may be implemented in a variety of ways that will be clear to one of ordinary skill in the art. Numerous applications of the invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | Systems and methods for data aggregation and analytics are disclosed. The systems query a participant for one or more behavioral and/or physical characteristics, receive data, and aggregate it into a participant profile. The disclosed systems and methods calculate the participant's performance based on said data and outputs the results of said calculation to one or more networked computers and/or one or more peripheral devices, associated with the participant or one or more individuals in charge of a study. The disclosed systems and methods are also capable of analyzing the participant data against historical data to identify correlations between the participant's data and adverse future health outcomes in real-time and clustering participants based on their behavioral and/or physical characteristics. | 6 |
[0001] This is a continuation application of application Ser. No. 09/830,511 filed Apr. 26, 2001.
BACKGROUND
[0002] The invention relates to plastic plates for conventional heat block thermocycling of biological samples, particularly to multiwell plates. More specifically, it relates to ultrathin-walled multiwell plates with an improved heat transfer to small-volume samples. Such plates can be used for rapid temperature cycling of multiple, small-volume samples (i.e. 1-20 μl) by using heat block thermocyclers with an increased block temperature ramping rate (i.e. 4° C./second and greater) and standard heated-lid technology for sealing the samples.
[0003] Temperature cycling of biological samples is a central moment in DNA amplification by the polymerase chain reaction (PCR) (Saiki et al., Science, 239, 487-491, (1988)). Much effort is being expended in developing various alternative reactors and technologies for rapid temperature cycling of small-volume samples (Kopp et al., Science 280, 1046-1048, (1998); Belgrader et al., J. Forensic Science 43, 315-319, (1998); Wittwer et al., Analytical Biochem., 186, 328-331 (1990) and U.S. Pat. No. 5,455,175; Woolley et al., Analytical Chem., 68, 4081-4086 ((1996)).
[0004] One commercially available type of microreactor and thermocycler for rapid temperature cycling of small samples is a glass capillary tube and a hot-air thermocycler from Roche Molecular Biochemicals (cat No. 1909 339 and cat No. 2011468, respectively). The glass capillary tube can hold reaction volumes ranging from 10 to 20 μl. The hot-air thermocycler can hold 32 capillaries and perform 30-40 PCR cycles in 20-30 minutes. However, this rapid DNA amplification technology has various disadvantages, for example:
[0005] a) The handling of the individual capillaries is relatively cumbersome.
[0006] b) The relatively large glass surface adsorbs components of the standard PCR-mixtures. This might inactivate the reaction. Therefore, various carrier molecules, i.e. proteins or even DNA, must be added and the concentrations of the components reoptimized.
[0007] c) The cost of the capillary tube, as a disposable PCR container, is high when compared to the standard 0.2 ml PCR tube.
[0008] d) The experimental throughput using this system is limited.
[0009] It is surprising that only little research has been conducted to improve the basic performance in sample size and speed of the widely used, conventional heat block thermocycling of samples contained in plastic tubes or multiwell plates.
[0010] One known improvement of heat block temperature cycling of samples contained in plastic tubes has been described by Half et al. (Biotechniques, 10, 106-112, (1991) and U.S. Pat. No. 5,475,610). They describe a special PCR reaction-compatible one-piece plastic microcentrifuge tube, i.e. a thin-walled PCR tube. The tube has a cylindrically shaped upper wall section, a relatively thin (i.e. approximately 0.3 mm) comically-shaped lower wall section and a dome-shaped bottom. The samples as small as 20 μl are placed into the tubes, the tubes are closed by deformable, gas-tight caps and positioned into similarly shaped conical wells machined in the body of the heat block. The heated cover to compresses each cap and forces each tube down firmly into its own well. The heated platen (i.e. heated lid) serves several goals by supplying the appropriate pressure to the caps of the tubes: it maintains the conically shaped walls in close thermal contact with the body of the block; it prevents the opening of the caps by increased air pressure arising in the tubes at elevated temperatures. In addition, it maintains the parts of the tubes that project above the top surface of the block at 95°-100° C. in order to prevent water condensation and sample loss in the course of thermocycling. This makes it possible to exclude the placing of mineral oil or glycerol into the wells of the block in order to improve the heat transfer to the tubes and the overlaying of the samples by mineral oil that prevented evaporation but also served as added thermal mass. In addition, the PCR tubes can be put in a two-piece holder (U.S. Pat. No. 5,710,381) of an 8×12, 96-well microplate format, which can be used to support the high sample throughput needs with any number between 1 and 96 individual reaction tubes.
[0011] In DE 4022792 the inventors describe a plate with cylindrically shaped walls of the wells and spherically shaped bottoms thereof. The individual wells of the plate were formed by melting a polycarbonate sheet in the range of 0.27-0.5 mm by a stream of hot air. This technology leads to relatively thin walls in the range of 0.08-0.2 mm. The biological samples were placed into the wells, covered with polycarbonate film (0.1 mm) and the individual wells were thermosealed by a special press. Upon sealing the plate was placed on the thermoblock and fixed by screws. Though theoretically the heat transfer to 30 the samples is improved, however, the way of positioning the plate on the block and the cylindrical and spherical geometry of the well prevent a close thermal contact with the heating block. During thermocyling, due to the large thermal expansion, the plate fixed by screws becomes deformed and the close thermal contact is not maintained anymore. Therefore, by using the above technology rapid cycling reactions cannot be performed.
[0012] Another known improvement of heat block thermocycling is described in PCT patent application WO 98/43740 and concerns a heat block thermocycler with an increased ramping rate, i.e. 4° C./second. The thermocycler can hold 96 PCR tubes (each of a volume of 0.2 ml) or 96-well PCR plates. Theoretically, the thermocycler can perform 30 PCR cycles in 20-30 minutes, provided that only a few seconds are spent to reach the temperature equilibrium between the heat block and the samples.
[0013] However, as described in U.S. Pat. No. 5,508,197, even if the temperature of the heat-transfer media, i.e. water, is changed almost instantaneously, it takes approximately 15 seconds to reach equilibrium between water and the 15-20 μl samples in the standard PCR plates. This means that for 30 PCR cycles approximately 20 minutes are spent to reach the equilibrium between heat-transfer media and the 15-20 μl samples in the plates.
[0014] In comparison, the above mentioned heat block cycler (WO 98/43740) operating at a ramping rate of 4° C./second, needs for the heat-block temperature transitions during 30 PCR cycles 10 minutes only. This shows that the major limiting factor for rapid temperature cycling of small samples in plastic PCR tubes or PCR plates is the low efficiency of the heat transfer through the walls of conventional PCR tubes or plates, respectively.
SUMMARY
[0015] The present invention concerns plastic multiwell plates for performing heat block thermocycling of multiple samples. More specifically, it concerns ultrathin-walled multiwell plates with an improved heat transfer to small samples. Ultrathin-walled multiwell plates are suited for rapid, oil-free, heat block temperature cycling of small volume samples (i.e. approximately 1-20 μl), whereas the lower limit is given by the reliability of the conventional pipetting systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 a is a plan view of an embodiment of a multiwell plate according to the present invention.
[0017] [0017]FIG. 1 b is a cross-sectional side elevation view of the multiwell plate of FIG. 1 a.
[0018] [0018]FIG. 2 is a cross-sectional side elevation view of the multiwell plate of FIG. 1 a positioned in a block of a thermal cycler.
[0019] [0019]FIG. 3 is a cross-sectional view of the multiwell plate without a support frame attached.
[0020] [0020]FIG. 4 is a cross-sectional view of a support frame having an array of holes for accepting the multi-well plate of FIG. 3.
[0021] [0021]FIG. 5 is perspective view of the support frame of FIG. 4.
DETAILED DESCRIPTION
[0022] One aspect of the present invention concerns a multiwell plate having a considerably decreased thickness (i.e. approximately 7.5-15 fold) of well walls when compared to known thin-walled PCR tubes (U.S. Pat. No. 5,475,610). This can be achieved, for example, by means of thermoforming the multiwell plates out of thin thermoplastic films. Such thermoplastic films are, for example, polyolefin films, such as metallocene-catalyzed polyolefin films and/or copolymer films. Usually, the multiwell plate is vacuumformed out of cast, unoriented polypropylene film, polypropylene-polyethylene copolymer films or metallocenecatalyzed polypropylene films. The film is formed into a negative (“female”) mould comprising a plurality of spaced-apart, conically shaped wells which are machined in the body of a mould in the shape of rectangular- or square-array. The thickness of the film for vacuumforming conically shaped wells is chosen according to the standard rule used for thermoforming, i.e. thickness of the film=well draw ratio×thickness of the wall of the formed well.
[0023] For example, vacuumforming wells with a draw ratio of two and an average thickness of the walls of 30 microns requires a film thickness of 60 microns. The average optimum wall thickness was found to be 20-40 microns. The thickness of the well is reduced 7.5-15 fold when compared to the wall thickness of the formerly improved PCR tube described in U.S. Pat. No. 5,475,610. Using the Fourier equation for heat transfer and the equation for temperature transfer through solid substances, it can be shown that heat transfer through one square millimeter of the surface of the well of the plate is increased 7.5-15 fold and the time of temperature transfer through the wall is decreased 56-225 fold when compared to the PCR tube. This drastic decrease in time can be explained by the fact that the time needed for the transfer of temperature front is proportional to the square power of distance. It can be easily calculated that the time of the temperature transfer through the ultrathin walls of the multi-well plate is in the range of milliseconds, whereas for the PCR tube (U.S. Pat. No. 5,475,610) it is in the range of seconds. This explains the well known fact that thin (20-40 microns) plastic films are poor theremo insulators.
[0024] The thickness of the walls of the formed wells is gradually reduced to the bottoms of the wells due to vacuumforming of the wells into a negative mould. This geometry of the walls of the wells provides several advantages:
[0025] The relatively thick upper parts of the walls of the wells cause additional rigidity of the whole multiwell plate. During heating of the heat block of the thermocycler, a vertical temperature gradient is formed in the sample, due to the gradient of the well-wall thickness. This vertical temperature gradient causes intensive convective mixing of the sample in conically shaped wells and increases the heat transfer through the sample. In comparison, this convective mixing of the sample is much less efficient in conventional PCR plates/tubes with a uniform wall thickness.
[0026] Another aspect of the invention concerns the height of the wells of the multiwell plate. The height of the conically shaped wells is equal to the height of the similarly shaped sample wells machined in the body of the heat block. Thus, this geometry of the wells ( 2 ) enables the positioning of the plate ( 1 ) on the heat block ( 4 ) as shown in FIG. 2. As shown (FIG. 2), in contrast to the conventional PCR plates, the walls of the wells ( 2 ) of the multi-well plate ( 1 ) do not project above the top surface of the block ( 4 ). The type of positioning provides several advantages: The pressure caused by the screw ( 12 ) to the lid ( 10 ) (heating element ( 11 )) can be increased in order to obtain efficient sealing of the samples ( 9 ) sealed, for example, by a silicon mat ( 13 ). In this case the pressure is to actually directed to those parts of the multiwell plate ( 1 ) which are supported by the top surface of the heat block ( 4 ) (or by parts of the top surface surrounding individual wells depending on the geometry of the heat block) and not to the thin walls of the wells of the plate as it is the case for the PCR tubes or conventional PCR plates. This advantage makes it possibe to increase the sealing pressure of the heated lid ( 10 ) several fold when compared to the conventionally used pressure of 30-50 g per well without cracking the conically shaped walls of the wells ( 2 ).
[0027] The extremely thin walls of the wells, i.e. 20-40 microns, are highly flexible as the multiwell plates are thermoformed out of highly elastic films (or sheets depending on the draw ratio). The walls of the wells are highly resistant against stress cracking, due to their flexibility and elasticity. As the wells of the plate, positioned on the heat block, are tightly sealed at room temperature, the air pressure in the wells will increase at elevated temperatures. The increased air pressure causes a deformation of the walls of wells and brings them in tight thermal contact with the surface of the walls of the individual sample wells machined in the body of the heat block. Standard PCR plates (having relatively thick and rigid walls of the wells) require that the conically shaped walls of the wells have to match perfectly with the shape of the wells machined in the body of the heat block to guarantee a close thermal contact (see for example U.S. Pat. No. 5,475,610). This requirement is not as critical for the ultrathin walled multiwell plates of the invention, due to flexibility and elasticity of the walls of the wells. Using this advantage, special shapes of both, the walls of the wells of the plate and the wells of the heat block can be differently designed. These differently designed wells can promote an even closer thermal contact after positioning the plate into the heat block.
[0028] Referring to FIGS. 3-5, another aspect of the invention concerns a support frame 3 ′ for a multiwell plate 1 . As the plates 1 can be formed of very thin films (depending on the draw ratio of the well; supra) the flexibility of, for example, standard-format plates, i.e. 96-well PCR (8,5×12,5 cm) plates, is such that handling is not easily possible anymore. Therefore, depending on the geometry of the plate 1 , a supporting frame might be needed, for example for industry standard formats, i.e. 96-, 192-, 384-well PCR plates. This frame can support, for example in case of small plates, the edges of the plate as shown in the form of a support frame 3 in FIGS. 1 a and 1 b, or individual wells of the plate, or groups of wells. For handling with robots, for example, the frame 3 ′ of FIGS. 3-5 can be injection molded in the form of the standard skirted microplates containing an array of holes 15 in a top surface of the frame 3 ′ matching the array of wells of the ultrathin multiwell plate 1 . The plate 1 can be attached to the frame 3 ′ by, for example, heat bonding. However, small format plates including a frame can be formed as a single piece by using specially designed moulds.
[0029] The polypropylene-based plastics are PCR-compatible and therefore widely used for injection molding of PCR tubes and/or multiwell plates. In addition, they are resistant to stress cracking and have a reduced water vapor sorption when compared to other plastics (e.g. polycarbonate). Such plates can be thermoformed in both, standard industry formats, i.e. 96-, 192 and 384-well PCR plates for large scale applications, supported by robots and small foot-print formats to match small foot-print thermocyclers, i.e. “personal thermocyclers”.
[0030] The following example serves to illustrate the invention but should not be construed as a limitation thereof.
EXAMPLE
[0031] [0031]FIG. 1 illustrates a 36-well ultrathin walled multiwell plate according to the invention. The plate was designed for rapid temperature cycling of samples ranging from 0.5-4 μl using a small foot-print pettier-driven heat block thermocycler supplied with a “wine-press” type heated lid (FIG. 2). The volume of the wells is 16 μl and the distance between the wells is 4.5 mm, i.e. industry standard for high sample density 384-well PCR plates. The diameter of the openings of the wells is 3.8 mm and the height of the wells is 3 mm. The average thickness of the walls of the wells is 30 μm. The frame ( 3 ) was cut out of a polypropylene sheet of a thickness of 0.5 mm and heat bonded to the plate ( 1 ). The area of the plate ( 1 ) is 30×30 mm. As shown in FIG. 1, the handling of the plate ( 1 ) containing the multiple wells ( 2 ) is facilitated, by a rigid 0.5-1 mm thick plastic frame ( 3 ) which is heat bonded to the plate. As shown in FIG. 2, the frame ( 3 ) is not in direct thermal contact with the block ( 4 ) during thermocycling because the inner contour ( 5 ) of the frame ( 3 ) matches the outer contour ( 6 ) of the heat block ( 4 ) of the thermocycler ( 7 =thermoelectric heat pump and 8 =air-forced heat sink).
[0032] The ultrathin walled multiwell plate according to the invention (FIG. 1) was experimentally tested for the amplification of a 455-base pairs long fragment of human papilloma virus DNA. The sample volume was 3 μl. For various PCR reactions, the average ramping rate of the thermo cycler was varied from 4° C. to 8° C. per second. The samples (i.e. standard PCR-mixtures without any carrier molecules) were transferred into the wells of the plate by means of conventional pipetting equipment. The plate was covered by standard sealing film (Microseal A; M J-Research, USA), transferred into the heatblock of the thermocycler and tightly sealed by the heated lid as shown in FIG. 2. Upon sealing, a number of 30 PCR cycles was performed in 15-25 minutes depending on the ramping rate of the thermo cycler. The PCR product was analyzed by conventional agarose electrophoresis. The 455-base pairs long DNA fragment was amplified with a high specificity at the indicated ramping rates (supra).
[0033] Plates according to the invention with well volumes of 35 μl were successfully tested for temperature cycling of samples of a volume of 20 μl. Thereby, 30 PCR cycles were performed in 20-30 minutes at a ramping rate of 6° C. per second. Surprisingly, although the average thickness of the walls was 20 microns and the volume of the wells was 35 μl, samples of a volume of as few as 0.5 μl can be easily amplified without reducing the PCR efficiency.
[0034] In conclusion, the ultrathin walled multiwell plates according to the invention, allow a simple and rapid loading of multiple samples by conventional pipettes, rapid sealing of all samples by using conventional sealing films and rapid DNA amplification (15-30 minutes for 30 cycles) with an improved specificity typical for rapid cycling (Wittwer et al., Analytical Biochem., 186, 328-331 (1990)) using appropriate heat block thermocyclers (i.e. ramping rate in the range of 4° C. to 8° C. per second). | An ultrathin-walled multiwell reactor for heat block thermocycling of samples includes an array of small-volume wells of identical height with similarly shaped sample wells formed in a top surface of a heat block. The multiwell plates are preferentially vacuum formed out of a 30-50 micron thick thermoplastic film and can be used for rapid, oil-free temperature cycling of small (1-10 μl) volume samples. | 1 |
This invention relates to educational and entertaining card games for all ages, with a great variety of players, and more particularly to a single card deck which may be used in many ways not only to play specific games, but also to encourage innovative players to invent their own games.
BACKGROUND OF THE INVENTION
There are card games which are similar to, but different from the invention, a few of which are shown and described in the following patents: Design U.S. Pat. Nos. 56,985; 118,977; and 169,557; and U.S. Pat. Nos. 627,046; 1,012,574; 1,076,307; 1,191,419; 1,320,899; 1,377,327; 1,401,001; 1,448,441; 1,485,146; 1,557,824; 1,705,883; 2,000,812; 2,042,930; 2,265,334; 4,333,656; 4,428,582; 4,775,157; 4,826,175; 4,923,199; 5,014,996; 5,092,777; 5,199,714; and 5,203,706.
These patents describe many different card designs and procedures for playing games; however, they are focused on some particular audience or style of playing. Hence, some games may be designed for small children. Other games may be designed for adults. Some games may be educational while other games are purely entertaining. In general, games involving a single deck of cards are not games which may be played by almost anyone from preschool to adults with a high level of interest for all persons. For the adult, the invention provides a wide range of games ranging from intellectual pursuits to the kind of almost trivial play which may be carried on while the main effort is socializing.
One disadvantage of card and similar games is that they appear to attract the public's interest for a while, and then disappear as the public's attention span wanes. Thus, there is a constant need for new games to replace those which have run their course. In order to increase its staying power and increase its life time, it is desirable for a deck of cards to have a great variety of different game uses so that play may be switched before boredom sets in. Also, the life time of and interest span for a deck of cards, or other game pieces, is greatly enhanced if creative people can invent and design their own games. Among other things, these features may be provided by cards having different values or symbols so that each game may be centered on a matching or scoring procedure which is convenient for such a game.
SUMMARY OF THE INVENTION
One advantage of the inventive game is that, if small children observe adults enjoying a game being played with the inventive deck of cards and if they find that they can enjoy a game also played with the same deck, there is a substantial inducement for the child to play such a game. Since the child's game is educational, there is a contribution to the child's learning curve. Thus, for the adult with an over riding interest in the child's learning, the use of the inventive cards with the enhanced attraction is of great importance.
Accordingly, an object of the invention is to provide a deck of game cards which has something for many different classes of people. In particular, an object is to provide a deck of cards having many different scoring and matching markers. Here an object is to provide a single deck which can function as flash cards for teaching very young children to read the alphabet or which can function as game pieces that can be used by adults to play a variety of games, many being sophisticated games. A further object is to provide a means for creating games which may be invented by the players themselves.
In keeping with an aspect of the invention, a deck of cards has a hundred and twenty-seven cards. Each of one hundred and four cards has a letter of the alphabet and a cartoon or cartoon-like picture which may appeal to very young children and still be cute for adult interests. Each of these cards also has an alphabetical letter in both upper and lower case for identifying the card and for teaching the alphabet when the deck is used as a flash card for children. The letter and cartoon are associated so that a young child seeing the cartoon character and pronouncing its name will likely use a correct pronunciation of the letter appearing on the card. A number also appears on the card to give its point value. To provide for variation in the games, the numbers may be printed in different colors or otherwise distinguished so that the point values may be tailored to the needs of particular games. The deck also includes special cards which introduce opportunity similar to the opportunities provided by chance cards which are drawn in various games, especially children's games, or to jokers and wild cards which are, perhaps, more appropriate for adult games.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows three cards of the one hundred twenty-seven cards.
FIG. 2 shows a joker wild card.
FIG. 3 shows a chance card.
FIGS. 4 thru 30 show all twenty-six alphabetical cards in a suit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In greater detail, each card 4 has a number 1 which is a point score value for the individual card. These points are awarded on a playing (or declaring in a meld) of the card carrying the number. Some of these numbers, may also be distinctively displayed, such as by being printed in red ink or enclosed in a square frame to give bonus or penalty points in some games. Both a capital and a lower case letter 2 and 5, respectively, have a phoneme which is the same as the initial sound of the name of the cartoon character 3 also printed on the card. Thus, a very young child seeing the airplane will make a partial sound similar to the sound of the spoken letter "A" which also appears on the card. Since there are four suits, the same cartoon may appear on each of four cards. Or, so that the child will quicker realize that the sound of "A" applies to many different words and not to just the name of a single cartoon character, each "A" card, for example, may have a different picture for each of the suits. For example, the "A" cards in the individual one of the four suits might, respectively, have cartoons of an airplane, arm, apple, and ant.
The four suits are identified by colors (red, blue, green and yellow) so that the small child may easily identify the suit, as distinguished from having to recognize special symbols such as the familiar hearts, spades, diamonds and clubs. The jokers and wild cards are printed in a different color, such as black.
Each deck has the following cards:
______________________________________NUMBEROF CARDS DESCRIPTION OF CARDS______________________________________26 Alphabetical letters A thru Z with a Crimson Red background.26 Alphabetical letters A thru Z with a Sky Blue background26 Alphabetical letters A thru Z with a Bright Green background.26 Alphabetical letters A thru Z with a Bright Yellow background.4 Extra letter "B" (two letters "B" appear on a card) appears on one card of each color background. (This double "B's" card means: "Back to You")4 Extra card with letter "L" (two letters "L" appear on a card appears on each color background. (This card means: "Lose your Turn").4 Extra card with letter "D" (two letters "D" appear on a card appears on each color background. (This D card means: "Draw a Card").11 Joker Wild Cards______________________________________
When the alphabetical identification value is critical, the cards with extra letters are played as if they were a single letter cards. That is, for example, to spell a word, the "B" and the "BB" cards are the same.
The alpha-numerical relationship values assigned to and printed on each of the cards are, as follows:
______________________________________A = 3 G = 4 M = 2 S = 1 Y = 8B = 2 H = 5 N = 1 T = 1 Z = 9C = 2 I = 3 O = 3 U = 3D = 4 J = 8 P = 6 V = 9E = 4 K = 5 Q = 7 W = 6F = 4 L = 1 R = 1 X = 7______________________________________
The remaining cards may or may not be assigned numerical values for each of the games that may be played with the deck.
One characteristic of the inventive deck of cards is that at least five different games may be played with it and further the deck lends itself to creative impulses to invent new games. This invitation to invent-your-own-game is important to all, but especially important for children who have a natural impulse to be creative.
All games played with the inventive deck involve the usual shuffling, playing in turn usually with the player on the left taking the next turn. Other conventions, such as determining who takes the first turn, can be adapted to accommodate such things as the age of the player; or, the first player may be selected by drawing a high or a low card. Most of the games may be played by two to six players; however, the size of the deck gives considerable room for innovatively accommodating different numbers of players.
Spelling Game
This is a spelling game, played with the object of accumulating the highest point score. The game ends when either all cards have been played or when no player can make a new word, which ever occurs first. In this spelling game, the jokers, with a point score of ten points, may be used as a substitute for any letter of the alphabet.
The game begins with each player being dealt a hand of eleven cards. A wild card is placed face up in the center of a playing surface, usually a table top. The remaining cards are placed face down in a draw pile on the playing surface. The first player forms a word by using cards from his hand, the face up wild card being used as any one of the letters in the formed word. The cards selected from the player's hand are then laid side by side on the playing surface, in either a horizontal row or a vertical column. The point scores on these cards are totaled and entered on a score card. Then, the player draws a number of cards from the draw pile in order to replace the cards that were selected and laid down on the playing surface in order to form the word.
The next player on the left forms a new word from the cards in his hand by using an exposed letter in the first word as one of the letters in his new words.
The play continues with each player taking a turn as play moves around the table in a clockwise rotation. Any player who can not form a new word misses his turn. Play ends when either no player can form a new word or when the pile is exhausted.
Flash
This game is primarily directed to smaller children who are in the process of learning the alphabet.
One person is designated as the "director", who will flash the cards, one card at a time until the entire deck of cards is exhausted. The object is to see who can score the most points (a sum total of the numbers on the cards) before the deck is exhausted and all cards have been flashed.
The playing procedure is for the director to flash each card, in turn. The first child to recognize the card claps his hands and says the letter. Then, the points on the flash cards are entered on the score card. To increase the interest for older children, and perhaps adults as well, the cards are flashed faster and faster. The penalty for clapping ones hands and then failing to say the correct letter is a deduction of the cards points from the players then existing score.
A variation is to begin with a score, such as "100" and to deduct the point score from the then existing score. The first player to reach zero wins.
Jokers Wild
The object of this game is to be the first player to reach a designated score, 800-points (or more) being the suggested score for ending the game. The player who discards the last card leading into the designated score gets a bonus of fifteen extra points, for example.
The game is started by dealing seven cards to each player and placing the remainder of the cards on a draw pile in the center. One card is turned over (face up) to start a discard pile.
The game is played by drawing one card before a play and then discarding one card after a play. The play is to lay three or more cards (a) of the same color and in an alphabetical sequence, or (b) of the same alphabetical character. A joker may be played as a substitute for any one of the alphabetical cards. The scoring is the sum total of the points on the cards which are laid down with jokers counting as five points.
If one player can add to a sequence of cards laid down by another player, a bonus of five extra points are added to the point value printed on each card that is so discarded.
If the pile is exhausted before the player's hands are exhausted, the discard pile is reshuffled and placed face down to replenish the draw pile.
Finders Keepers
The object of this game is to match pairs of alphabetical letters. The score is made by entering on a score sheet the number on one of the pair of cards. Alternatively, each matched pair of cards can count as a single point so that every pair has a value equal to every other pair.
To play "finders keepers", all jokers and wild cards are removed from the deck, leaving only the alphabetically designated cards. The cards are laid out, face down, in a plurality of rows and columns. Any two cards are selected and turned over. If they match, the player removes and keeps the matching cards and then turns over two more cards. If the selected cards do not match, they are placed face down and play moves to the next player.
The game ends when the last of the face down cards has been removed from the rows and columns. The winner is the player who has collected the most cards.
Zap
The object of this game is to accumulate a designated score (such as 800-points) or to be the person who places their last card on the discard pile.
The game is played by dealing seven cards to each player. The remainder of the cards are placed face down in a draw pile, with one card turned up to form a discard pile. If a joker appears as the turned up card, a designated player (usually in the rotational position of the first or next player) will declare it to be a certain color so that play can begin. Each player discards a card, in turn, the allowed discard being either an alphabetical or a color match of the last card which is showing on the discard pile. A wild card can be used as any letter or any color. If the player is unable to discard, he draws a card from the pile.
If the extra "B" cards is played on the discard pile, the direction of play rotation reverses (e.g. an existing clockwise rotation of play changes to a counter clockwise rotation of play or visa versa). If the "L" card is played, the next player in the rotation loses his turn. A joker is somewhat like a wild card which may be played as a card of any color or letter; however, it causes the next player in rotation to draw three cards from the pile and to lose his turn.
If for any reason a player can not discard, the play goes on to the next player.
When any player plays his last card, and says "zap", the game is over.
If the draw pile is exhausted, the last discarded card remains as the start of the next discard pile. The remainder of the discard pile is then reshuffled and placed face down as a new draw pile.
Those who are skilled in the art will readily perceive how to modify the invention. Therefore, the appended claims are to be construed to cover all equivalent structures which fall within the true scope and spirit of the invention. | A deck of cards is adapted to enable all ages to play a game (of many games) which is of interest to them. Each of 104 cards in a deck of cards has an alphabetical letter and a numerical value along with a cartoon which begins with a phoneme that corresponds to the letter so that the cards may be used as flash cards to teach the alphabet to small children. Some games require only a matching to two alphabetical characters. Other games are designed to permit players with low scores to "gang-up" on players with high scores. Still other games fit between these extremes to challenge the players skills and to provide games of interest to various age groups. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Application PCT/NL01/00744, filed Oct. 10, 2001, designating the United States, published in English Apr. 18, 2002, as WO 02/31510 A1, the contents of which are incorporated herein by this reference.
FIELD OF THE INVENTION
The present invention relates to the field of molecular recognition or detection of discontinuous or conformational binding sites or epitopes corresponding to or interacting with a binding molecule, in particular, in relation to protein-protein or protein-ligand interactions.
BACKGROUND OF THE INVENTION
Interactions between binding molecules, which in general are biomolecules and their corresponding ligands, are central to life. Cells often bear or contain receptor molecules that interact or bind with a hormone, a peptide, a drug, an antigen, an effector molecule or with another receptor molecule; enzymes bind with their substrate; antibody molecules bind with an antigen, nucleic acid with protein, and so on. By “interact or bind” it is meant that the binding molecule and ligand approach each other within the range of molecular forces and may influence each other's properties. This approach takes the binding molecule and its ligand through various stages of molecular recognition comprising increasing degrees of intimacy and mutual effect: they bind.
Binding molecules have this binding ability because they comprise distinct binding sites allowing for the recognition of the ligand in question. The ligand, in turn, has a corresponding binding site, and only when the two binding sites can interact by—essentially spatial—complementarity, the two molecules can bind. Needless to say, molecules having three dimensions have binding sites that are of a three dimensional nature, often one or more surface projections or protuberances of one binding site correspond to one or more pockets or depressions in the other, a three-dimensional lock-and-key arrangement, sometimes in an induced-fit variety.
Sometimes, such a protuberance comprises a single loop of the molecule in question, and it is only this protuberance that essentially forms the binding site. In that case, one often terms these binding sites as comprising a linear or continuous binding site, wherein a mere linear part of the molecule in question is essentially responsible for the binding interaction. This terminology is widely used to describe, for example, antibody-antigen reactions wherein the antigen comprises part of a protein sequence, a linear peptide. One then often speaks about a linear or continuous epitope, wherein the binding site (epitope) of the antigenic molecule is formed by a loop of consecutively bound amino acids. However, similar continuous binding sites (the terms “epitope” and “binding site” are used interchangeably herein) can be found with receptor-antigen interactions (such as with a T-cell receptor), with receptor-ligand interactions such as with hormone receptors and agonists or antagonists thereof, with receptor-cytokine interactions, or with, for example, enzyme-substrate or receptor-drug interactions, whereby a linear part of the molecule is recognized as the binding site, and so on.
More often, however, such a protuberance or protuberances and depressions comprise various, distinct parts of the molecule in question, and the combined parts essentially form the binding site. Commonly, one names such a binding site comprising distinct parts of the molecule in question a discontinuous or conformational binding site or epitope. For example, binding sites laying on proteins having not only a primary structure (the amino acid sequence of the protein molecule), but also secondary and tertiary structure (the folding of the molecule into alpha-helices or beta-sheets and its overall shape), and sometimes even quaternary structure (the interaction with other protein molecules) may comprise in their essential protuberances or depressions amino acids or short peptide sequences that lay far apart in the primary structure but are folded closely together in the binding site.
Due to the central role binding molecules and their ligands play in life, there is an ever expanding interest in testing for or identification of the nature or characteristics of the binding site. Notably, the rapid developments in evolving biotechnology fields such as proteomics will result in the near future in the identification of more and more binding molecules and their corresponding ligands. The detection of protein-protein interactions and enzyme-substrate interactions (not only of protein enzymes but certainly also of for example catalytic RNA-based interactions), and the identification of protein-nucleic acid and of nucleic acid-nucleic acid pairs of binding molecule and corresponding ligand, will certainly result in generating more interest in where the exact interacting (binding) sites between these molecules lay and how one can develop compounds (agonists, antagonists, drugs) modulating the specific interaction.
Not only is one interested in the exact nature of the particular interaction between binding molecule and ligand in question, for example, in order to replace or supplement binding molecules or ligands when needed, but one is also interested in knowing approximating characteristics of the interaction in order to find or design analogues, agonists, antagonists or other compounds mimicking a binding site or ligand involved.
Versatile and rapid methods to test for or identify continuous epitopes or binding sites are known. Most, if not all, nucleic acid detection techniques, and molecular libraries using these, entail hybridization of an essentially continuous nucleic acid stretch with a complementary nucleic acid strand, be it DNA, RNA or PNA. Little attention has been paid to methods allowing rapid and straightforward identification of discontinuous binding sites of an essentially nucleic acid nature. Although plenty of such sites exist, think only of the lack of understanding surrounding ribosomal binding sites where ribosomal proteins bind to tRNA, of regulatory sites in promoter sequences, of interactions between polymerases and replicases between DNA and RNA, of catalytic RNA reactions, and so on, no molecular libraries exist that provide easy access to such sites.
An early work in the peptide field is disclosed in PCT International Publication No. WO 84/03564, related to a method of detecting or determining antigenically active amino acid sequences or peptides in a protein. This work, providing the so-called Pepscan technology, whereby a plurality of different peptides is synthesized by linking with a peptide bond a first amino acid to a second, and so on, and on a second position in the test format yet another first amino acid is linked to a second, and so on, after which the synthesized peptides are each tested with the binding molecule in question, allows the determination of every continuous antigenic determinant or continuous epitope of importance in a protein or peptide sequence. Pepscan technology taken in a broad sense also provides for the testing for or identification of (albeit linear) peptides essentially identical with, analogous to or mimicking binding sites or ligands of a various nature (mimotopes, Geyssen et al., Mol. Immunol. 23:709-715, 1986).
Pepscan technology allows identification of linear peptide sequences interacting with receptor molecules, enzymes, antibodies, and so on, in a rapid and straightforward fashion, allowing testing of a great many peptides for their reactivity with the binding molecule in question with relatively little effort. The order of magnitude of testing capability having been developed with Pepscan technology (e.g., also due to miniaturization of test formats; see, e.g., PCT International Publication No. WO 93/09872) furthermore allows at-random testing of a multiplicity of peptides, leading to automated combinatorial chemistry formats wherein a great many binding molecules are tested in a (if so desired at-random) pattern for their reactivity with a molecular library of synthetic peptides representing potential continuous binding sites or ligands, allowing the rapid detection of particularly relevant molecules out of tens of thousands of combinations of molecules tested.
However, for the testing of discontinuous or conformational binding sites to a binding molecule, no formats similar to or as versatile as Pepscan technology exist. Attempts to identify discontinuous epitopes by Pepscan technology are cumbersome. It does, in general, not suffice to merely extend synthesis of the test peptides by linking more amino acids to the existing peptide and hoping that some of the thus formed longer peptides will fold in such a way that at least two distinct parts are presented in a discontinuous fashion and are recognized by a binding molecule. In that case, there is no way of finding out in a rapid and straightforward fashion that the binding is indeed through a discontinuous binding site; it might be that just a longer single loop is responsible for the binding.
Some additional possibilities are provided by testing synthetic peptide sequences that have been designed to comprise two previously identified parts of a binding site, each part in essence being linear and being part of a larger linear peptide. Early work herein was done by Atassi and Zablocki (J. Biol. Chem 252:8784, 1977) who describe that spatially or conformationally contiguous surface residues (which are otherwise distant in sequence) of an antigenic site of egg white lysozyme were linked by peptide bonds into a single peptide which does not exist in lysozyme but attempts to simulate a surface region of it. However, their technique, called surface simulation synthesis, requires detailed knowledge of the three-dimensional structure of the protein under study and a full chemical identification of the residues constituting the binding site beforehand, as well as their accurate conformational spacing and directional requirements.
In the same fashion, Dimarchi et al. (Science 232:339-641, 1986) describe a 38 to 40 amino acid-long synthetic peptide consisting of two previously identified separate peptidyl regions of a virus coat protein. The peptide was synthesized using common peptide synthesis technology (Merrifield et al., Biochemistry 21, 5020, 1982) by adding subsequent amino acids with a peptide bond to an ever growing peptide resulting in a peptide wherein the two peptidyl regions were connected by a diproline spacer presumably functioning as indication of a secondary structural turn, thereby providing a two-part epitope or binding site.
However, it is clear that when one has to know beforehand the sequence of the (in this case only) two relevant parts in order to provide the desired discontinuous binding site, it excludes the feasibility of providing (desirably in a random fashion) a whole array of merely potential discontinuous binding sites for large scale testing. Furthermore, a major drawback of the above-mentioned strategies is that, again, only linear epitopes or dominant binding regions of discontinuous epitopes can be mimicked adequately. For the more complete synthesis of a discontinuous binding site, all the contributing parts have to be arranged in the proper conformation to achieve high-affinity binding. Therefore, single parts of discontinuous binding sites have to be linked.
Fifteen years after Dimarchi, Reineke et al. (Nature Biotechnology, 17:271-275, 1999) provided a synthetic mimic of a discontinuous binding site on a cytokine and a method to find such a discontinuous binding site that allowed for some flexibility and somewhat larger scale testing, wherein positionally addressable peptide collections derived from two separate regions of the cytokine were displayed on continuous cellulose membranes and substituted in the process to find the best binding peptide. After selection of the “best reactors” from each region, these were combined to give rise to another synthetic peptide collection (comprising peptides named duotopes) that again underwent several rounds of substitutions.
Reineke et al. thus provide synthesis of peptide chains comprising duotopes, however, again selected after previous identification of putative constituting parts with Pepscan technology, thereby still not allowing testing discontinuous binding sites in a rapid and straight forward fashion.
However, as indicated before, protein domains or small molecules that mimic binding sites are playing an increasing role in drug discovery, diagnostics and biotechnology. The search for particular molecules that bind to a binding site and mimic or antagonize the action of a natural ligand has been initiated in many laboratories. As indicated before, attempts to find such structures in synthetic molecular libraries often fail because of the essentially discontinuous nature and spatial complementarity of most binding sites.
Thus, for the many more cases where the binding site may essentially be discontinuous, improved means and methods to identify these sites are needed, and, in particular, means and methods are needed that allow testing for discontinuous binding sites whereby said parts need not necessarily first be selected by previous identification as a putative or even only tentative constituting part of the desired discontinuous binding site but bear only the potentiality of being part of that site by being a molecule with more or less distinct features per se.
BRIEF SUMMARY OF THE INVENTION
The invention provides a method for producing a molecular library comprising providing the library with a plurality of test entities wherein said entities have essentially been produced by segment spotting, that is, by spotting, placing, or attaching in close proximity at least two (di-, tri-, oligo- or multimeric) segments of, for example, nucleic acids or peptides directly or indirectly to a solid phase, such as an array surface, instead of by sequentially synthesizing test molecules and spotting one molecule, or several replicas of said one molecule, as a single entity, which is done traditionally. In theory, the segments can be sequentially synthesized in close proximity to each other, whereby in a repetitive fashion one monomer (e.g., a nucleotide or an amino acid) to another until a (in essence polymeric) molecule (segment) of the desired length has been obtained.
Essentially, existing nucleic acid libraries comprise nucleic acids that are synthesized sequentially by adding one nucleotide or nucleoside at a time to the growing stretch, and existing peptide libraries comprise peptides that are synthesized sequentially by adding one amino acid at the time to a growing stretch until the desired length has been reached. However, with existing libraries, no attention is given to synthesizing specific segments in close proximity to each other so that they together can represent a putative binding site. With nucleic acids, the monomers are essentially selected from a limited set of well known nucleotides. With peptides, the monomers are essentially selected from a well known set of amino acids. Not only naturally occurring monomers are used. Synthetic nucleotides, such as peptide nucleic acid (PNA) molecules, non-naturally occurring amino acids, or even D-amino acids, are routinely used as monomers by which the essentially polymeric molecules are generated or produced using a method that is essentially in conformity with the sequential synthesis of polymers from monomeric molecules in nature. Preferred, according to the invention, however, is synthesizing the segments before they are attached to the solid phase in close proximity, thereby it is easier to create the desired test entity, the putative binding site composed of two or more segments located in close proximity and attached to the solid phase, e.g., the array surface.
In close proximity herein reflects the possibility that a putative binding molecule can bind to at least two of the closely spotted segments or parts thereof and is defined in angstrom units, reflecting the generally molecular scale of the binding sites. It is preferred to attach the two or more segments that form the desired test entity at no more than 100 angstroms away from each other, however, obviating the need of long linkers, or when small segments are used, distances of smaller than 50, or preferably smaller than 30, or even smaller than 15 angstroms, are preferred, the smaller distances in general creating a better fit for binding sites. Minimal proximity is 1-2 angstroms, whereby the segments are, for example, linked to variously protected thiol groups only 1-2 atoms on the polymer away from each other. Furthermore, the length of a flexible linker should preferably be 10-100 angstroms, where the preferred length of segments is at about 5-100 angstroms and where the preferred distance between the tops of segments amounts to 0-30 angstroms.
For example, two segments can be coupled, preferably as loops, onto a (polycarbon)-polymer surface. With extra spaced building blocks (for example, phenylalanine amino acids) it is provided to obtain extended loops. On the (polycarbon)-surface, for example, two types (see FIG. 1 for suitable types) of protected cysteines (e.g., cys (trt) and cys (mmt)) and, for example, one spacing building block is coupled. The cys (mmt) is deprotected with 1% TFA while the cys (trt) remains protected. The first segment is coupled to the deprotected cys (mmt). Then, the second cys (trt) is deprotected with 95% TFA. Then, the second segment is coupled to the now deprotected cys (trt). If desired, segments can also be linked together using appropriate chemistry.
Alternatively, instead of directly linking the segments to the surface (albeit via linkage groups), the segments may be first linked to a template that itself is linked to the surface. In a preferred embodiment, such a template is, for example, a peptide. For example, two segments can be coupled onto a cyclic template that itself is coupled to the polymer surface. The cyclic template is, for example, a cyclic flexible peptide. The cyclic peptide contains, for example, reactive groups such as four lysines (mmt), two cysteines (trt) and two cysteines (butyl). The template is, for example coupled to the resin via a sulphur.
The invention thus provides a molecular library that, albeit also suited for detecting or screening for continuous binding sites, is now particularly well suited for detecting or screening for discontinuous binding sites, in particular in relation to binding molecule-ligand interactions such as, for example, protein-protein, protein-nucleic acid, and nucleic acid-nucleic acid interactions, now that at least two different segments, each of which may represent a part of a discontinuous binding site, are spotted as single entity, tentatively representing a possibly as yet unknown discontinuous binding site, herein also called a binding body.
As used herein, the term “binding body” is generally used for essentially all-peptide segment constructs, however, the technology, as described for all-peptide combinations, can of course also be used for nucleic acid combinations or combinations of an even more mixed nature. A binding body, which is in essence a synthetic molecule comprising a binding site identifiable or obtainable by a method according to the invention as described herein, is essentially a combination of random peptide segments (fixed into one molecule or represented as one molecule on a test s which acts as a binding molecule such as an antibody. Just as in the case of antibodies, the recognition may more or less be “degenerate,” i.e., the binding site on the target molecule need not always be optimal. The binding body may in principle bind to any part of the target molecule. For instance: to neutralize the action of TNF-alfa, one might develop a small molecule that specifically interacts with the receptor binding site on TNF-alfa; alternatively, one might develop an antibody that interacts with TNF-alfa at an as yet undefined place and neutralizes its action. This shows that sometimes small molecules are the solution and sometimes large antibodies. Unfortunately, both have their disadvantages: small molecules are difficult or impossible to make for large recognition sites, and large molecules like antibodies are much easier to develop but cannot be used intracellularly and have all sorts of pharmacological disadvantages like their immunogenicity and their inability to act inside the cell.
The advantageous properties of the binding body combine those of small and large molecules: binding bodies share advantages of both. A preferred binding body consists of random peptide segments, for example, slightly biased or shuffled to resemble CDRs or other binding domains. If needed or desired, CDRs may be mimicked by using, for example, 6 segments, each representing one possible CDR, however, combinations of 2, 3 or 4 segments will already provide diversity. The peptide segments preferably are linked at both sides to a scaffold or solid phase. Thus, binding bodies are made up of molecules with one, two or more peptide segments.
Highly diverse binding body libraries can be generated based on systematic combination of relatively small numbers of random peptide segments. A library of 100 binding bodies is easily produced using positionally defined peptide segment arrays as described herein. Screening of such a library with any given molecule is simple, fast and straightforward. Hits can be translated directly into the amino acid or segment make up of the binding body due to the positionally defined array. A library of 10,000 binding bodies can be easily generated by combining all peptides from smaller libraries with each other or by starting with a larger solid support surface. A library of 1,000,000 binding bodies can, for example, be easily generated by combining all peptides of smaller libraries into binding bodies that contain three segments. Thus, a large diversity of binding bodies can be generated starting with relatively small numbers of random peptides (for instance, 10) and multiple combinations of peptides combined into a single binding body (for instance, 6) to arrive at a diversity of 1,000,000 or even larger.
Alternatively, the same binding body diversity can be obtained starting with, for example, 1000 random peptides and using just two peptide segments for each binding body. Just like antibodies, binding bodies can “mature.” Based on hits obtained with an initial set of random binding bodies (above), new dedicated libraries can be generated that will contain a high number of improved combinations. The best ones can be selected or improved in an additional round using a second dedicated library, and so on. Development of high affinity binding bodies is thus provided by chemistry to bind peptides, preferably both ends, to a molecular scaffold or solid phase by using an array system in which each binding body is positionally defined, further by appropriate miniaturization and/or by appropriate bioinformatics to analyze the data and to design subsequent improved binding bodies or dedicated libraries of binding bodies.
The two or more different segments can, of course, each be selected at random from any set of di-, tri-, or oligomeric sequences, such as from di-, tri,- or oligonucleotides, or di-, tri-, or oligopeptides, but sometimes, it may be preferred to include at least one specific segment in the entity, specific in the sense that it has been selected from among known segments or distinct parts of biomolecules, such as parts of genes, proteins, enzymes, nucleic acids or unique fragments thereof, proteins involved in up- or down-regulation of translation, t-RNAs, SNRPs, antibodies, complementarity determining regions (CDRs), antigens, receptors, transport proteins, transcription factors or factors involved in up- or down-regulation of transcription, promoter sequences such as, but not necessarily restricted to, the well known TATA-box elements, repressor sites, operator sites and other control elements, polymerases, and replicases, in short, from among known segments or distinct parts of binding molecules known or suspected to be involved in binding via a discontinuous binding site.
Known segments or parts thereof spotted in close proximity may, of course, be already known as parts constituting a discontinuous binding site. However, previous identification as such is essentially not necessary, since screening for such sites with a molecular library according to the invention allows rapid and straightforward identification of the constituting segments or parts thereof.
Screening such a library can easily be envisioned when the library's molecules differ only in that constituting segments are chosen in an overlapping fashion, whereby a first segment from a distinct biomolecule is spotted next to a second, and to a third, and to a fourth segment, and a second is spotted next to a third, and to a fourth, and so on, if so required, until all possible segments of the biomolecule have been spotted in close proximity two-by-two (or three-by-three, or even more) together, which allows for a systematic screening of possible discontinuous binding sites present on the biomolecule.
However, an overlapping fashion is, of course, not required. Random segment combinations spotted in close proximity will provide valuable information about binding sites as well.
The invention thus provides a method for producing a molecular library for identification or detection of a binding site capable of interacting with a binding molecule, and, thus, for the identification of a molecule as a binding molecule, the method comprising providing the library with a plurality of segments derived from binding molecules or their ligands, further comprising spotting at least two of the segments in a pair, or three in a threesome, or more in the respective plurality, preferably a greater part of the pairs, threesomes on pluralities, most preferably essentially all of the pairs, threesomes or pluralities, by at least spotting a first segment next to a second segment, for example, a segment which comprises a dimer, trimer, oligomer or multimer.
Existing libraries, be they of, for example, nucleic acid (containing a repetitive back-bone of nucleotides, nucleosides or peptide nucleic acid, or combinations of these) or amino acid (containing a repetitive back-bone of amino acids) nature have in general in common that single molecules (or single segments) or a plurality of replicas of the single molecules are spotted and used as the entity representing the binding site. Such libraries comprise oligomeric or multimeric molecules, such as stretches of nucleic acids or amino acids, that have been produced by sequentially linking, in a repetitive fashion, one monomer (e.g., a nucleotide or an amino acid) to another, until a (in essence polymeric) molecule of the desired length has been obtained.
Essentially, existing nucleic acid libraries comprise nucleic acids that are synthesized sequentially by adding one nucleotide or nucleoside at a time to the growing stretch, and existing peptide libraries comprise peptides that are synthesized sequentially by adding one amino acid at the time to a growing stretch, until the desired length has been reached. With nucleic acids, the monomers are essentially selected from a limited set of well known nucleotides. With peptides, the monomers are essentially selected from a well known set of amino acids. Not only naturally occurring monomers are used. Synthetic nucleotides, such as peptide nucleic acid (PNA) molecules, non-naturally occurring amino acids, or even D-amino acids, are routinely used as monomers by which the essentially polymeric molecules are generated or produced using a method that is essentially in conformity with the sequential synthesis of polymers from monomeric molecules in nature. These single monomers are then spotted in a single fashion, one monomer thought to represent the full, or nearly the full, binding site, without taking into consideration the multiple parts of a binding site constituting a discontinuous binding site.
The invention provides the recognition that essentially using dimeric or even larger (tri-, oligo-, or multimeric) segments in combination, thus in pairs or threesomes or even more, offers distinct advantages. It not only provides a faster method to arrive at or recognize a molecule composed of various segments, it also provides for fast and efficient shuffling of segments to generate a molecule or test entity repertoire for the desired library. The invention for example provides a method wherein synthesis is started with a monomer in close proximity to which a second segment comprising a dimer, such as a dinucleotide or a dipeptide, is spotted. Herein, a segment comprising a dimer at least consists of a dimer but can also be, for example, a trimer or any-other multimer linking monomers of any nature, as required. Of course, once two segments have been spotted in close proximity, further segments can be added thereto.
In a preferred embodiment, to speed up further synthesis, or to be able to select distinct desired segments, the invention provides a method wherein the first segment also comprises a dimer, and in a yet even more preferred method, further segments comprise dimers as well. In a preferred embodiment, the dimer comprises a dinucleotide or dipeptide, but of course other dimers can be made also. The invention is further explained in the detailed description where several of the examples relate to libraries comprising molecules wherein each of the segments comprises a peptide, such as a tri-, a penta-, an octa-, or nonapeptide. It is, however, also provided by the invention to use longer segments, e.g., 10 to 15, 15 to 20, 20 to 30 or 30 to 40 amino acids or nucleic acids long or longer and to use of a varied nature, e.g. wherein one comprises a nucleic acid and another comprises a peptide, to better mimic binding sites that are found, for example, on nucleic acid-protein complexes.
In a preferred embodiment, as, for example, shown in the examples, the invention provides a method wherein the first segment is spotted or attached to the solid phase by a thioether bond next to the second segment; however, the invention is, of course, not limited thereto. Nucleotide/side segments can, for example, be covalently linked or ligated by splicing enzymes or ligases or by overlapping a first segment and the second segment with an in essence relatively short nucleotide strand that is partly complementary to both segments.
The invention thus provides a molecular library allowing testing for, identification, characterization or detection of a continuous or discontinuous binding site capable of interacting with a binding molecule, the library having been provided with pluralities (pairs, threesomes, foursomes, fivesomes, sixsomes) of segments, each plurality preferably comprising at least one first segment spotted in close proximity to a second segment, wherein at least the second segment previously existed as a dimer or a multimer. Preferably, each segment or part thereof having the capacity to be a potential single part of a discontinuous binding site, preferably wherein each of at least a first and a second segment or part thereof represents a potential single part of a discontinuous binding site. Such a library can, for example, comprise a synthetic molecular library made by chemical spotting of segments.
Preferably, such segments have distinct features, for example, by being in essence segments that are, comprise or mimic molecular components of living organisms, such as (combinations of) nucleotides, sugars, lipids, amino acids, nucleic acid molecules (DNA or RNA), peptide nucleic acid molecules (PNA), carbohydrates, fatty acids or fats.
Herewith, the invention provides synthesis of molecules comprising, separate segments potentially representing at least two distinct parts of a discontinuous binding site, the parts not necessarily first being selected after previous identification of potential constituting parts, thereby allowing testing for discontinuous binding sites in a rapid and straightforward fashion.
The invention thus now allows identifying discontinuous binding sites of receptor molecules that interact or bind at a contact site with a hormone, a peptide, a drug, an antigen, an effector molecule or with another receptor molecule, of enzymes that bind with their substrate, of antibody molecules that bind with a binding site on an antigen, nucleic acid that binds with protein, and so on. In a preferred embodiment of the invention, at least one of the segments comprises a peptide, another segment being, for example, DNA, RNA, PNA, carbohydrate, a fatty acid, a peptide, a hormone or an organic molecule altogether. In one embodiment of the invention, all segments comprise a peptide. In this way, a plurality of different binding bodies is synthesized by spotting a first segment next to a second, and so on, and on a second position in the test or library format yet another first segment is linked to a second, and so on, after which the synthesized binding bodies are each tested with the binding molecule in question, allowing the determination of a discontinuous antigenic determinant or discontinuous epitope of importance in, for example, a nucleic acid, a protein or peptide sequence.
The peptide segment comprises at least two amino acids and can, in principle, be as long as desired, e.g., containing a hundred amino acids or even more. In preferred practice, the peptide segment comprises from 3 to 30, preferably from 4 to 20, even more preferably from 5 or 6 to 12 to 15 amino acids, such as 9 or 12 amino acids. Separate segments, of course, do not necessarily have to be of equal length.
Furthermore, peptide segments to be spotted together, or at least in close proximity to each other, can be selected at random, or under guidance of (a) known protein or peptide sequence(s). Selection at random provides a random library according to the invention. Selection from known protein or peptide sequences is, for example, useful when it is desired to find out whether a discontinuous binding site is composed of distinct sites or parts present at distinct proteins or peptides, for example, in a protein complex to which a particular binding molecule can bind. Selection of various peptide segments from one known protein or peptide sequence is useful when it is desired to find out whether a discontinuous binding site is composed of distinct sites or parts present at one protein or peptide, for example, at a folded protein to which a particular binding molecule can bind. Selection of peptide segments can be done by selecting overlapping peptides from such a known sequence. Overlapping peptides can have, for example, all but one or two amino acids in common, preferably overlapping in a contiguous fashion, or can overlap with only one or several amino acids. For a quick scan for discontinuous binding sites on a known protein, it is, for example, useful to select nonapeptide segments from the protein sequence, of which one has, for example, a 5-amino acid-long overlap with another peptide segment. Equally useful, however, is to select tripeptide segments from the sequence having an overlap of only one amino acid and to use three, or even more, segments in constructing the putative binding site molecule to which the to-be-tested binding molecule can bind.
Of course, such selection strategies are equally applicable to segments of a different nature, nucleic acid segments comprising a certain number of nucleotides, such as 5, 7, 9, and so on, can be selected from known nucleic acid sequences comprising putative or sought-after discontinuous binding sites, each segment selected from a certain position in the known nucleic acid sequence, if desired also in an overlapping fashion. The nucleic acid segment comprises at least 2 nucleotides (be it DNA, RNA or PNA, or functional equivalents thereof), and can, in principle, be as long as desired, e.g., containing a hundred nucleotides or even more. In preferred practice, the nucleic segment comprises from 3 to 30, preferably from 4 to 20, even more preferably from 5 or 6 to 12 to 15 nucleotides, such as 9 or 12 nucleotides. Separate segments, of course, do not necessarily have to be of equal length, and, as the before, can even be of a different nature, e.g., peptide with DNA.
The segments can, for example, be chemically attached to the solid phase by chemical links or bonds. The links or bonds can be formed using many combinations of strategies of, for example, peptide or nucleotide chemistry and selective ligation reactions, as known in the art. Ligation chemistry has been published, for instance, by groups of Kent (Ph. E. Dawson et al., “Synthesis of Proteins by Native Chemical Ligation,” Science 266 (1994) 776-779), Tam (J. P. Tam et al., “Peptide Synthesis using Unprotected Peptides through Orthogonal Coupling Methods,” Proc. Natl. Acad. Sci. USA 92 (1995) 12485-12489); C. F. Liu et al., (“Orthogonal Ligation of Unprotected Peptide Segments through Pseudoproline Formation for the Synthesis of HIV-1 Protease Analogs,” J. Am. Chem. Soc. 118 (1996) 307-312); L. Zhang & J. P. Tam, (“Thiazolidone Formation as a General and Site-specific Conjugation Method for Synthetic Peptides and Proteins,” Analytical Biochemistry 233 (1996) 87-93), and Mutter (G. Tuchscherer & M. Mutter, “Protein Design as a Challenge for Peptide Chemists,” J. Peptide Science 1 (1995) 3-10); S. E. Cervigni et al., (“Template-assisted Protein Design: Chimeric TASP by Chemoselective Ligation, Peptides: Chemistry, Structure and Biology,” P. T. P Kaumaya & R. S. Hodges eds, Mayflower (1996) 555-557).
Possible strategies for the formation of links as preferably provided by the invention are, for example:
1. The link of a segment or segments with a solid phase is formed using a homo- or hetero-bifunctional linking agent (S. S. Wong: Chemistry of Protein Conjugation and Cross-Linking, CRC Press Inc, Boca Raton, Fla. USA 1991). In this construction, a reactive group in a segment is used to react with one part of the bifunctional linking agent, thus facilitating the second part of the linking agent to react with a reactive group from a solid phase, or visa versa. For instance, a linker like MBS (m-maleinimidobenzoic acid N-hydroxysuccinimide ester) can be used to react via its active ester (succinimide) with an amino group of one segment and via its maleinimide group with a free thiol group from a solid phase, or visa versa. In this strategy, when linking preferably no other free amino or thiol groups should be present in the segment. In order to accomplish this, the amino or thiol groups that should be involved in the reaction can be deprotected selectively, for instance, by using a side chain protecting group that can be cleaved by a mild reagent like 1% trifluoroacetic acid, which leaves other side chain protecting groups intact.
2. The link is formed by introduction of a modified amino acid in the synthesis of one or more segments. Amino acids can be modified, for instance, by introduction of a special group at the side-chain or at the alpha-amino group. A modification at the alpha-amino group leads to an amide or backbone modified peptide (see, e.g., Gillon et al., Biopolymers, 31:745-750, 1991). For instance, this group can be a maleinimido group at the side chain amino group of lysine. At the end of the peptide synthesis, this group will react fast and selective with a thiol group of a solid phase. Tam et al. (PNAS 92:12485-12489, 1995) described a synthesis of a peptide with a lysine residue that was modified in the side chain with a protected serine residue. After deprotection and selective oxidation using periodate, the alpha-amino, beta-hydroxy function of the serine is converted into an aldehyde function that can be ligated selectively with another thiol-bearing surface. Also, peptide backbone links, via groups attached to the amide groups of the peptide, can be used to spot segments (Bitan et al., J. Chem. Soc. Perkin Trans.1:1501-1510, 1997; Bitan and Gilon, Tetrahedon, 51:10513-10522, 1995; Kaljuste and Unden, Int. J. Pept. Prot. Res. 43:505-511, 1994).
3. Yet another way to form the link is to synthesize a segment, such as a peptide, with a modified N-terminus. For instance, an N-terminal alpha-haloacetamido group can be introduced at the end of the synthesis. This group reacts fast and selectively with a solid phase which contains a thiol group. For instance, the first segment is synthesized with an N-terminal bromoacetamide and the solid phase is provided with a cysteine. Although most alpha-haloacetamide groups, like chloro-, bromo-, or iodoacetamide, will react with thiol groups, in those cases where speedy assembling is required, the bromoacetamide group is preferred because of its ease of introduction and fast and selective reaction with thiol groups.
Furthermore, the invention provides the possibility to address the link in every position of the first and/or the second or consecutive segment. For instance, for peptide segments, sets of peptides are synthesized in which a cysteine or a side-chain modified lysine (both amino acid residues, in a preferred embodiment, being able to ligate selectively with another segment) shifts from the N-terminal amino acid position one by one to the C-terminal amino acid position. Combinations of these possibilities will, again, lead to libraries as provided by the invention.
In another preferred embodiment, the segments are linked at least twice in close proximity to the solid phase, preferably by linking the respective ends of the segments to the surface, so that, so-to-speak, looped segments are attached to the solid phase. In such a preferred embodiment, pairs (or larger pluralities) of looped segments are attached to the solid phase, presenting themselves as binding bodies.
In a preferred embodiment, the invention provides a library wherein the pluralities are positionally or spatially addressable, e.g., in an array fashion, if desired aided by computer directed localization and/or recognition of a specific pair or threesome (or larger plurality) or set of pluralities within the dimensions (e.g., plane or surface) of the support or solid phase of the library used. In an array, the pluralities are, for example, addressable by their positions in a grid or matrix.
A preferred embodiment of the invention further allows upscaling of the synthesis concerning the number of constructs on, for example, a solid support per square centimeter. To facilitate generation of a great many possible constructs, containing, for example, test entities (pairs, threesomes or larger pluralities) comprising at least two peptide segments of a protein, many thousands of peptide constructs are made. For instance, when all constructs in which both segments are, for instance, twelve amino acids long are derived from a small protein with a length of 100 amino acid residues are needed, already 89×89=7,921 peptide constructs are made if the segments are only linked to the solid phase, for instance, via the C-terminus for the first segment and the N-terminus of the second segment, or visa versa, or both, using only one type of link. For a protein with a length of 1,000 amino acid residues, at least 989×989=978,121 constructs are made. For efficient ELISA testing of these numbers of constructs, high construct densities on the solid support are preferred. High densities of constructs on a solid support are provided by the invention, wherein, for instance, (a layer of) a first segment with a bromoacetamide group at the N-terminus is synthesized on a surface of, for instance, 1 cm 2 . On yet another part of the surface, another first-segment may be applied. On each of such a peptide-functionalized surface of the support, a set of, for instance, 10, preferably 50, preferably 100, or more second, peptide segments containing a free thiol group are spotted or gridded in a positionally or spatially addressable way, giving, after coupling, so many different peptide pairs. Spotting can, for instance, be done using piezo drop-on-demand technology, or by using miniature solenoid valves. Gridding can, for instance, be done using a set of individual needles that pick up sub-microliter amounts of segment solution from a microtiter plate containing solutions comprising the second segments. After the linking reaction, subsequent deprotection and extensive washing of the support to remove uncoupled peptide gives at least a peptide construct pair density as large as 10 to 50, or even 100 to 200, or up to 50 to 1000 spotted pairs per square centimeter. This density allows the screening of a great many possible peptide pairs or binding bodies derived from the proteins for binding with an antibody. For example: in a preferred embodiment 20,000 to 100,000 constructs are made on 1000 cm 2 . Typically, the surface is then screened for binding in ELISA with 100 ml of antibody s 1-10 μg of antibody/ml. For example, indirect or direct fluorescence detection allocates antibody binding constructs. Direct fluorescence detection with confocal scanning detection methods, for example, allows antibody detection on spots generated with droplets of peptide-solution in the sub-nanoliter range, making even higher construct densities feasible. Of course, nucleic acid libraries can be made in a similar fashion.
Furthermore, the invention provides a solid support comprising a library according to the invention, the solid support allowing presentation of a potential discontinuous or conformational binding site or epitope to a binding molecule, the solid support having been provided with a plurality of test entities, each pair or threesome or larger plurality of the test entities or binding bodies being a possible representative of the binding site or epitope and, for example, comprising at least one first peptide or nucleotide, for example, covalently linked to a solid phase and a second peptide or nucleotide.
In a preferred embodiment, the solid support comprises at least a spot or dot (e.g., putative binding site, test entity, or pair of segments) density as large as 10, 20, or 50, or even 100, 200, or up to 500 or even 1,000 spots per cm 2 , preferably wherein the spots or dots are positionally or spatially addressable.
The invention further provides a method to screen for, i.e., test, identify, characterize or detect a discontinuous binding site capable of interacting with a binding molecule, comprising screening a library as provided by the invention with binding molecules, such as there are, for instance, antibodies, soluble receptors, which contain a Fc-tail or a tag for detection, receptors on cells, biotinylated molecules or fluorescent molecules.
Alternative segments could comprise, for instance, carbohydrates, non-natural amino acids, PNAs, DNAs, lipids, or molecules containing peptide bond mimetics. In particular, the invention provides a method to screen for a discontinuous binding site capable of interacting with a binding molecule, comprising screening a library according to the invention with at least one test entity and detecting binding between a member of the library and the test entity. In a preferred embodiment, the binding is detected immunologically, for example, by ELISA techniques.
By detecting binding to a specific test entity (herein also called a binding body) of the library, the invention provides the member or binding body a synthetic molecule comprising the binding body or test entity or pair or larger plurality of (looped) segments comprising a discontinuous binding site identifiable or identified or obtainable or obtained by a method according to the invention. Thus, the invention provides use of a library according to the invention, use of a solid support or solid phase or array surface provided with one or more binding bodies or test entities according to the invention, or use of a method according to the invention for identifying or obtaining a synthetic molecule comprising a discontinuous binding site or a binding molecule capable of binding therewith. Because discontinuous binding sites are now provided, such a synthetic molecule can advantageously be used in vitro or in vivo for finding a binding molecule and for effecting and/or affecting binding to a binding molecule, for example, to interact or bind with receptor molecules that normally interact or bind with a hormone, a peptide, a drug, an antigen, with an effector molecule, with an agonist, with an antagonist, or with another receptor molecule, with enzymes that normally bind with their substrate, with antibody molecules, with nucleic acid, with protein—in short—with biomolecules. The invention is further explained in the detailed description without limiting the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 : six different cysteines that can be used in coupling of bromine under different conditions.
FIG. 2 : (spotting with dark coloring) Analysis of two different peptides for showing the advantageous effect of two-sided linking and the formation of loops. On the left, the peptide has an amino-terminal Br. On the right the peptide has an amino-terminal Br and a C-terminal Lysine-Br (synthesized as described in legend FIG. 4B ). Test was carried out in a miniwell setup (3 ul each well). Surface is functionalized with thiol groups (—SH groups). Peptides were coupled to the surface using the bromine- (Br—) group of the peptide. Different concentrations of peptide were used for coupling to the surface. Two sets of peptides were used, one with one Br-group and the other (differs only from the previous peptide by an extra lysine+Br-acetyl moiety on the C-terminal site of the peptide) with two Br-groups. Binding was determined using differed antibody concentrations in an ELISA setup.
FIG. 3 : Proximity of segments after coupling on solid-support. On the left side: on a minimal distance of 2 angstrom, linkers of 15 angstrom are coupled. The segments are coupled to these linkers. The flexibility of the linkers allows the termini of the two segments to move within distances of 0 to 30 angstroms. On the right side: the distances between the linkers can be varied from 2 to 50 or more. As an example, 9 angstrom is shown. This allows the termini of the two segments to move within distances of 0 to 40 angstroms.
FIG. 3B : Schematic representation of how the two segments are linked as loops to the poly-carbon polymer surface. The preferred distances, at least in the case of CDR-derived binding bodies, between the tops of the loops are 0 to 30 angstroms, which is similar to that of the CDRs in an antibody.
FIG. 4 : Schematic representation of how two segments can be coupled onto the (polycarbon)-polymer surface. The drawing shows four examples. In Example-1, two linear segments are coupled. In Example-2, two looped segments are coupled. In Example-3, two segments are coupled as loops. In Example-4, two segments are coupled as loops. With extra spaced building blocks (e.g., phenylalanine amino acids) two obtain extended loops. On the (polyearbon)-surface, two types of protected cysteines (cys (trt) and cys (mmt) ) and, for example, one spacing building block is coupled. The cys (mmt) is deprotected with 1% TFA, while the cys (trt) remains protected. The first segment is coupled to the deprotected cys (mmt). Then, the second cys (trt) is deprotected with 95% TFA. Then, the second segment is coupled to the now deprotected cys (trt).
FIG. 4B : Schematic representation of how two segments can be coupled onto a cyclic template that itself is coupled to the polymer surface. The cyclic template is a cyclic flexible peptide. The cyclic peptide contains four lysines (mmt), two cysteines (trt) and two cysteines (butyl). The peptide is coupled to the resin via a sulphur that is sensitive to 1% TFA. At the amino-terminus, a bromine is attached as described previously. The procedure is as follows: The synthesized peptide is treated with 1% TFA. This results in deprotection of the lysines and de-coupling of the peptide from the resin. The cysteines remain protected. After raising the pH to 8, the N— and C-terminus of the peptide are linked through the S and Br. Then, the —NH 2 on the deprotected lysines is coupled to Br. The resulting cyclic peptide, with four Br and still four protected cysteines, is coupled to the linkers via the Br. To the cyclic template coupled to the linker-cysteines, two peptide segments are coupled. First, the two cysteines (trt) are deprotected with 95% TFA. Then, the first segment is coupled. Second, the two cys (butyl) are deprotected with NaBH 4 . Then, the second segment is coupled.
FIG. 4C : Schematic representation of how two segments can be coupled onto two other segments that are coupled to the polymer surface. With free —SH on the surface, two segments are coupled to the surface via a N— and C-terminal Br. The N-terminal Br is synthesized as described previously. The C-terminal Br is linked to a C-terminal Lysine as described in FIG. 4B . Both segments contain protected cysteines on which two other segments are also coupled, as described in FIG. 4B .
FIG. 5 : Schematic representation of matrix-scan with two segments. On the polymer surface, a mixture of cys (mmt) and cys (trt) are coupled. After 1% TFA, the cys (mmt) is deprotected. Then, in each square one peptide is coupled via one or two terminal Br. Thus, peptide-1 in square-1, peptide-2 in square-2, etc., to peptide-100 in square-100. Then, the cys(trt) is deprotected with 95% TFA. Then, 100 different peptides are spotted in each square. Thus, peptide-1 to 100 in square-1, peptide 1 to 100 in square-2, etc., to peptide-1 to peptide-100 in square-100.
FIG. 6 : Binding-assay of all overlapping 30-mers covering the linear sequence of hFSHR with the biotinylated synthetic 40-mer hFSH-peptide biotin-EKEEARFCISINTTWAAGYAYTRDLVYKDPARPKIQKTAT-CONH2 (SEQ ID NO: 1). The 30-mer peptides were spotted as described, and the 40-mer peptides were synthesized using standard FMOC-chemistry. The various 30-mer peptides were incubated with 1 microgram/ml hFSH-peptide. After washing, the peptides were incubated with streptavidin-peroxidase, and subsequently after washing, with peroxidase substrate and H 2 O 2 .
FIG. 7 : Schematic representation of the development of synthetic mimics of discontinuous binding sites on the hTSHR and hTSH. On thyroid cells, the hTSH-receptor binds hTSH. The autoimmune antibodies from Graves and Hashimoto patients also bind the hTSH-receptor. Through screening of all overlapping 30-mers of hTSH, segments of the discontinuous binding site for hTSHR are identified (as described for FSH, see legend FIG. 6 ). Through screening of all overlapping 30-mers of hTSHR, segments of the discontinuous binding sites for Graves and Hashimoto antibodies are identified. Through modeling and usage of synthetic templates, the individual segments are combined into one discontinuous synthetic mimic.
FIG. 8 : Schematic representation of an array comprising synthetic mimics of discontinuous binding sites or binding bodies. Binding bodies are selected and improved by making arrays that contain a multiplicity of spatially addressable binding bodies on the solid surface (or, alternatively, on a separate molecular scaffold). The arrays can be incubated with target to screen for binding bodies that bind the target of interest. Lead binding bodies can be improved by making follow-up arrays composed of multiple variants of the lead binding bodies, e.g., by sequence shuffling. If the desired specificity and/or affinity is reached, the binding bodies can be produced onto a scaffold and produced and used in bulk.
FIG. 9 : Schematic representation of the development of synthetic mimics of discontinuous binding sites or binding bodies derived from CDR sequences. Binding bodies are constructed by positioning on a solid phase or array surface (preferably a (polycarbon)-polymer surface) or on predefined scaffolds or templates. Binding bodies can be derived from the Complementarity Determining Regions (CDRs) of antibodies or any other protein motif that is known to bind other molecules, preferably with high affinity.
FIG. 10 : Standard linear Pepscan on all overlapping synthetic 12-mers covering the linear sequence of hTNF with monoclonal antibody 210 (R&D Systems, MAB210, clone 1825.12, through ITK Diagnostics Uithoorn, The Netherlands). A small peak with the sequence IKSPCQRETPEG (SEQ ID NO: 2) was identified. The y-axis are optical density values (OD) obtained using a ccd-camera system. Rampo, rabbit-anti-mouse peroxidase (DAKO).
FIG. 11 : Partial listing of peptides synthesized for loop-loop 15-mer Matrix-scan (1. +AVRSSSRTPSDKPVZ (SEQ ID NO: 3); 2. +VRSSSRTPSDKPVAZ (SEQ ID NO: 4); 3. +RSSSRTPSDKPVAHZ (SEQ ID NO: 5); 4. +SSSRTPSDKPVAHVZ (SEQ ID NO: 6); 5. +SSRTPSDKPVAHVVZ (SEQ ID NO: 7); 145. +FAESGQVYFGIIALZ (SEQ ID NO: 8)). All overlapping 15-mer loop-peptides covering the linear sequence of human tumor necrosis factor (hTNF) were synthesized, i.e., 145 hTNF loop-peptides in total. Z is a Cys-butyl. The amino terminus of all peptides contain a bromo-group (+).
FIG. 12 : Configuration of the loop-loop 15-mer Matrix-scan. Schematic representation of matrix-scan with two loop segments. On the polymer surface, a mixture of cys (mmt) and cys (trt) are coupled. After 1% TFA, the cys (mmt) is deprotected. Then, in each square, one peptide is coupled via its N-terminal Bromo-group (+). Thus, peptide-1 in square -1, peptide-2 in square-2, etc., until peptide-145 in square-145. Then, the cys(trt) is deprotected with 95% TFA. Then, in each square, 145 different peptides are spotted simultaneously. Thus, peptide-1 to 145 in square-1, peptide 1-145 in square-2, etc., to peptide-1 to peptide-145 in square-145. Some extra squares were used for controls (linear epitopes).
FIG. 13 : Result of the loop-loop 15-mer Matrix-scan with anti-hTNF mAb 210 (10 ug/ml). The result obtained with all 145 squares is plotted. Squares 66, 67 and 92 to 96 are clearly labeled (firstly coupled loop-peptides). On top of these and other squares spots are labeled as well (spots represent first peptide coupled next to second loop peptide). Identified squares and spots: Sq-65:+FKGQGCPSTHVLLTZ (SEQ ID NO: 9); Sq-66:+KGQGCPSTHVLLTHZ (SEQ ID NO: 10); Sq-67:+GQGCPSTHVLLTHTZ (SEQ ID NO: 11); Sq-87:+SYQTKVNLLSAIKSZ (SEQ ID NO: 12); Sq-88:+YQTKVNLLSAIKSPZ (SEQ ID NO: 13); Sq-94:+LLSAIKSPCQRETPZ (SEQ ID NO: 14); Sq-95:+LSAIKSPCQRETPEZ (SEQ ID NO: 15); Sq-127:+LEKGDRLSAEINRPZ (SEQ ID NO: 16); Sq-128:+EKGDRLSAEINRPDZ (SEQ ID NO: 17); Peptide-65:+FKGQGCPSTHVLLTZ (SEQ ID NO: 18); Peptide-70:+CPSTHVLLTHTISRZ (SEQ ID NO: 19); Peptide-72:+STHVLLTHTISRIAZ (SEQ ID NO: 20); Peptide-77:+LTHTISRIAVSYQTZ (SEQ ID NO: 21); Peptide-94:+LLSAIKSPCQRETPZ (SEQ ID NO: 22); Peptide-95:+LSAIKSPCQRETPEZ (SEQ ID NO: 23); Peptide-99:+KSPCQRETPEGAEAZ (SEQ ID NO: 24); Peptide-126:+QLEKGDRLSAEINRZ (SEQ ID NO: 25); Peptide-129:+KGDRLSAEINRPDYZ (SEQ ID NO: 26). The y-axis is in arbitrary units.
FIG. 14 : Result of the loop-loop 15-mer Matrix-scan with mAb 210 (10 ug/m) with details of squares 65 and 127. Combination of loop-peptide 65 with loop-peptides 94, 95, combinations of loop-peptide 65 with 126-127, combinations of loop-peptide 127 with loop-peptides 65-77 and combinations of loop-peptide 127 with loop-peptides 94-96 are labeled. The y-axis is in arbitrary units.
FIG. 15 : Three dimensional representation of the identified binding loop-loop peptides with mAB-210 (10 ug/ml). Shown are the three regions identified (peptides 65-69, 94-96 and 1-26-127): GQGCPSTHVLLTHTIS (SEQ ID NO: 27) (VLLT are labeled); SAIKSPCQRE (SEQ ID NO: 28) (KSPC are labeled); KGDRLSAEINR (SEQ ID NO: 29) (SA are labeled).
FIG. 16 : Result of the loop-loop 15-mer Matrix-scan of loop-loop CDR-regions of antibodies with lysozyme-biotin (100 ug/ml, in triplo). Using 1 μg/ml lysozyme-biotin no binding is observed (not shown). Controls of only streptavidin-peroxidase in between the tests were negative (not shown). Peptides A, B, C, D, E and F: Peptide-A: +ARERDYRLDYZ (SEQ ID NO: 30) (HCDR3 of 1fdl.pdb); Peptide-B: +ARGDGNYGYZ (SEQ ID NO: 31) (HCDR3 of 1mlb.pdb); Peptide-C: +LHGNYDFDGZ (SEQ ID NO: 32) (HCDR3 of 3hfl.pdb); Peptide-D: +ANWDGDYZ (SEQ ID NO: 33) (HCDR3 of 3hfm.pdb); Peptide-E: +ARRYGNSFDYZ (SEQ ID NO: 34) (HCDR3 of 1qfw.pdb); Peptide-F: +ARQGTAAQPYWYZ (SEQ ID NO: 35) (HCDR3 of 1qfw.pdb) (1 fdl.pdb, 1 mlb.pdb, 3hfl.pdb and 3hfm.pdb are antibodies that bind lysozyme; 1 qfw.pdb are two antibodies that bind human choriogonadotrophin). All peptides have an amioterminal bromo-group (+) and a carboxyterminal lysine-mmt (Z).
Peptides 1 to 27:Peptide-1:+RASGNIHNYLAZ (SEQ ID NO: 36) (LCDR1 of 1fdl.pdb); Peptide-2:+RASQSISNNLHZ (SEQ ID NO: 37) (LCDR1 of 1mlb.pdb); Peptide-3:+SASSSVNYMYZ (SEQ ID NO: 38) (LCDR1 of 3hfl.pdb); Peptide-4:+RASQSIGNNLHZ (SEQ ID NO: 39) (LCDR1 of 3hfm.pdb); Peptide-5:+RASESVDSYGNSZ (SEQ ID NO: 40) (LCDR1 of 1qfw.pdb); Peptide-6:+ASESVDSYGNSFZ (SEQ ID NO: 41) (LCDR1 of 1qfw.pdb); Peptide-71:+SESVDSYGNSFMZ (SEQ ID NO: 42) (LCDR1 of 1qfw.pdb); Peptide-8:+ESVDSYGNSFMQZ (SEQ ID NO: 43) (LCDR1 of 1qfw.pdb); Peptide-9:+RASESVDSYGNSFZ (SEQ ID NO: 44) (LCDR1 of 1qfw.pdb); Peptide-10:+ASESVDSYGNSFMZ (SEQ ID NO: 45) (LCDR1 of 1qfw.pdb); Peptide-11:+SESVDSYGNSFMQZ (SEQ ID NO: 46) (LCDR1 of 1qfw.pdb); Peptide-12:+RASESVDSYGNSFMZ (SEQ ID NO: 47) (LCDR1 of 1qfw.pdb); Peptide-13:+ASESVDSYGNSFMQZ (SEQ ID NO: 48) (LCDR1 of 1qfw.pdb); Peptide-14:+RASESVDSYGNSFMQZ (SEQ ID NO: 49) (LCDR1 of 1qfw.pdb); Peptide-15:+KASETVDSFVSZ (SEQ ID NO: 50) (LCDR1 of 1qfw.pdb); Peptide-16:+LLVYYTTTLADGZ (SEQ ID NO: 51) (LCDR2 of 1fdl.pdb); Peptide-17:+LLIKYVSQSSSGZ (SEQ ID NO: 52) (LCDR2 of 1mlb.pdb); Peptide-18:+RWIYDTSKLASGZ (SEQ ID NO: 53) (LCDR2 of 3hfl.pdb); Peptide-19:+LLIKYASQSISGZ (SEQ ID NO: 54) (LCDR2 of 3hfm.pdb); Peptide-20:+LLIYRASNLESGZ (SEQ ID NO: 55) (LCDR2 of 1qfw.pdb); Peptide-21:LLIFGASNRESGZ (SEQ ID NO: 56) (LCDR2 of 1qfw.pdb); Peptide-22:+QHFWSTPRTZ (SEQ ID NO: 57) (LCDR3 of 1fdl.pdb); Peptide-23:+QQSNSWPRTZ (SEQ ID NO: 58) (LCDR3 of 1mlb.pdb); Peptide-24:+QQWGRNPTZ (SEQ ID NO: 59) (LCDR3 of 3hfl.pdb); Peptide-25:+QQSNSWPYTZ (SEQ ID NO: 60) (LCDR3 of 3hfm.pdb); Peptide-26:+QQSDEYPYMYTZ (SEQ ID NO: 61) (LCDR3 of 1qfw.pdb); Peptide-27:+GQTYNHPYTZ (SEQ ID NO: 62) (LCDR3 of 1qfw.pdb) (1 fdl.pdb, 1 mlb.pdb, 3hfl.pdb and 3hfm.pdb are antibodies that bind lysozyme; 1 qfw.pdb are two antibodies that bind human choriogonadotrophin). All peptides have an amioterminal bromo-group (+) and a carboxyterminal lysine-mmt (Z).
The loop-loop peptide pair, +LHGNYDFDGZ (SEQ ID NO: 32) +SESVDSYGNSFMQZ (SEQ ID NO: 46) (loop of HCDR3 of 3hfl.pdb with loop of LCDR1 of 1qfw.pdb) that has the highest binding activity is indicated by arrow.
FIG. 17 : Result of Pepscan ELISA with two different antibodies on single or double peptide loops coupled to Pepscan minicards, as described above. Coupled to square-A: Loop peptide-1; Coupled to square-B: first Loop peptide-1 followed by Loop peptide-2; Coupled to square-C: Loop peptide-2; Coupled to square-D: first Loop peptide-2 followed by Loop peptide-1. Loop peptide-1:+KSYNRVTVMGGFKVEZ-conh2 (SEQ ID NO: 63); Loop peptide-2:+LQENPFFSQPGAPILZ-conh2 (SEQ ID NO: 64). The y-axis are optical density values (OD) obtained using a ccd-camera system. Both loop-peptides are derived from human Follicle-Stimulating Hormone (hFSH).
DETAILED DESCRIPTION OF THE INVENTION
Synthesis of Peptide Constructs
A polypropylene or polyethylene support, or of other suitable material, was grafted with, for instance, polyacrylic acid. As an example: a polypropylene support in a 6% acrylic acid solution in water containing CuSO 4 was irradiated using gamma radiation at a dose of 12 kGy. The grafted solid support containing carboxylic acid groups was functionalized with amino groups via coupling of t-butyloxycarbonyl-hexamethylenediamine (Boc-HMDA) using dicyclohexylcarbodiimide (DCC) with N-hydroxybenzotriazole (HOBt) and subsequent cleavage of the Boc groups using trifluoroacetic acid. Subsequently, the surface is functionalized with (when preferred, a mixture of differently protected) Cys amino acids using standard Fmoc chemistry. Examples of differently protected Cys groups are Cys (Trt) and Cys (mmt). After removal of the FMOC, the amino group is acetylated. Side chain deprotection can be done as described. Standard Fmoc peptide synthesis chemistry was used to link peptides (segments) on to the amino functionalized solid support. After cleavage of the Fmoc group of the last amino acid and washing, bromoacetic acid was coupled using DCC or DCC/HOBt. A second bromoacetic acid (in the same step) can be coupled to the surface when, for example, a lysine (Lys) residue is present in the peptide: The side chain protection chemistry of Lys (using FMOC-Lys(MTT)-OH) allows that only the amino group of the Lys-side chain is liberated (with 1% trifluoracetic acid in dichloromethane), while the other amino acids still stay protected. Subsequently, if only DCC was used, the peptide did contain a thiol reactive bromoacetamide group. However, if DCC/HOBt was used to couple bromoacetic acid, the peptide essentially did not contain the bromo group, but another reactive group capable of reacting efficiently with thiol groups, thus forming the same thioether link between the segments. Coupling/ligation of a second peptide next to a peptide coupled or synthesized on a solid support: Bromo functionalized peptides can be coupled to the solid support (when a thiol is present) in an aqueous solution containing a sodium bicarbonate buffer at about ph 7-8. Peptides were synthesized at polyethylene pins grafted with poly-hydromethylmethacrylate (poly-HEMA). This graft polymer was made by gamma irradiation of polyethylene pins in a 20% HEMA solution in methanol/water 80/20 or 70/30 at a dose of 30-50 kGy. The functionalized support can be used for the synthesis of 1 μmol of peptide/cm 2 after coupling of β-alanine and an acid labile Fmoc-2,4-dimethoxy-4′-(carboxymethyloxy)-benzhydrylamine (Rink) linker. The peptides were synthesized using standard Fmoc chemistry, and the peptide was deprotected and cleaved from the resin using trifluoroacetic acid with scavengers. The cleaved peptide containing a cysteine residue at a concentration of about 1 mg/ml was reacted with the solid support described above in a water/sodium bicarbonate buffer at about pH 7-8, thus forming a partially protected construct of two peptides each at least once covalently bound via a thioether bond to the solid support. The construct described above was deprotected following standard procedures using trifluoroacetic acid/scavenger combinations. The deprotected constructs on the solid support were extensively washed using disrupting buffers containing sodium dodecylsulphate and β-mercaptoethanol and ultrasonic cleaning and were used directly in ELISA. Subsequent cleaning in the disrupt buffers allows repeated testing against antibodies in ELISA.
According to these methods, a library of constructs, for example, consisting of a dodecapeptide segment coupled via its C-terminally added cysteine residue next to a N-terminally bromoacetylated second segment, allowing scanning a protein sequence, for example, by steps of a single amino acid residue. The bromoacetamide peptide was covalently bound to a functionalized polypropylene/polyacrylic acid solid support in 3 μl wells, as described above. The cysteine-containing sequences are synthesized on and cleaved from functionalized polyethylene pins, as described above. Peptides are synthesized on a surface of a solid support, as described above. On this peptide functionalized support, a second peptide segment containing a free thiol group was spotted using piezo drop-on-demand technology using a microdosing apparatus and piezo autopipette (Auto Drop-Micropipette AD-K-501) (Microdrop Gesellschaft fur Mikrodosier Systeme GmbH). Alternatively, spotting or gridding was done using miniature solenoid valves (INKX 0502600A; the Ice Company) or hardened precision ground gridding pins (Genomic Solutions, diameters 0.4, 0.6, 0.8 or 1.5 mm). Subsequent deprotection of the construct and extensive washing to remove uncoupled peptide gave binding body constructs at the spotted area. Peptide constructs generated with peptide solution droplets in the nanoliter-range bind enough antibody for detection, in this case using indirect fluorescence detection. Spots generated with 0.25 nl-50 nl are smaller than 1 mm. Thus, in this set-up, binding body density can be as large as 100-1000 spots per square centimeter. When using smaller equipment, densities can even be higher.
In short, a thiol fuction is introduced on an amino-functionalized solid support. This can be made by a direct reaction of the amino groups with, for instance, iminothiolane or by coupling of Fmoc-Cys(Trt)-OH, followed by Fmoc cleavage using piperidine, acetylation, and trityl deprotection using TFA/scavenger mixtures. This thiol-functionalized solid support can be reacted with, for instance, a bromoacetamide-peptide containing a protected cysteine residue. After coupling of the first peptide, the cysteine can be deprotected using, for instance, a TFA/scavenger mixture. As yet unused free thiol groups can be used to couple a second bromoacetamide-peptide, again containing a protected cysteine. This procedure can be repeated to make segment constructs. Several types of scans can be used in combination with this multi-segment scan.
EXAMPLES OF USE
Proteins and peptides can be screened using any type of binding molecule, e.g., biomolecules such as antibodies, soluble receptors (which contain a Fc-tail or a tag for detection), biotinylated molecules or fluorescent molecules. Alternative segments could be, for instance, carbohydrates, non-natural amino acids, PNAs, DNAs, lipids, and molecules containing peptide bond mimetics.
TSH Example
The design and synthesis of synthetic mimics of discontinuous binding sites of large proteins such as TSH or TSHR is currently desired. Toward this aim, template based mimics of proteins have provided a powerful new tool for basic research. Technology provided herein enables one to map discontinuous binding sites, couple these onto a synthetic template and monitor in detail the structural and functional characteristics.
Pivotal to this approach is the possibility of synthesizing and testing of 100,000s of synthetic peptides in array-format. This is possible with the technologies provided herein. These include peptide-array synthesis and new methodology in template chemistry. Through chemistry, all kinds of synthetic groups are coupled on two or more different positions on these templates, allowing reconstruction of the discontinuous binding sites and the synthesis of mimics. The development of methods that allow mapping of discontinuous binding sites between large proteins is a major research target. Various strategies have been adopted with moderate success. The most successful techniques to date include X-ray crystallography, Combinatorial libraries and Mass-Spectrometry.
We provide a new approach involving peptide-arrays. Peptide array technology has long been used to identify short linear peptides involved in binding. All overlapping linear peptides (12-15-mers) of a given protein are synthesized on a solid-support such as plastic or paper and incubated with the target protein, most often an antibody. Those peptides that are recognized are so-called linear epitopes. Discontinuous epitopes could not be detected. Nevertheless, the early peptide-array technology laid the foundation for methods that identify discontinuous epitopes in a systematic fashion. This made it possible to couple on an array surface any part of a protein (for instance, a peptide of 15 amino acids long) next to any other part of a protein (for instance, a peptide of 15 amino acids long) in any orientation. These arrays, with all possible combinations of peptides, showed in our hands to allow accurate definition of discontinuous epitopes ( FIG. 2 ).
We now focus on discontinuous epitopes involved in Graves disease and Hashimoto disease, but others are as well within reach. The thyroid diseases are autoimmune diseases against the thyroid. The antibodies bind discontinuous epitopes on the thyrotropin receptor on the thyroid gland. Overactivation (Graves) or blockage (Hashimoto) of the thyroid gland leads to serious health problems. Mapping of both the antibody binding regions as well as the TSH binding region greatly contributes to the understanding of both diseases. Subsequently, hTSH and hTSHR mimics of these discontinuous epitopes will be used in new diagnostic tools allowing early discovery of Graves and Hashimoto disease. Studies on human Follicle-Stimulating Hormone (hFSH) and its receptor (hFSHR) have revealed discontinuous binding sites. Biotinylated 40-mers covering various regions of hFSH were tested in a peptide-array binding-assay as herein provided on all overlapping 30-mers covering the linear sequence of hFSHR.
One of the 40-mers clearly bound to a receptor region ( FIG. 1 ). Based on these results a similar study on the hTSH/hSHR couple hTSHR, a hormone-receptor couple that is structurally very similar to the hFSH/hFSHR couple, provides peptides that can be used as diagnostic tools for Graves and/or Hashimoto disease. Patients with Graves or Hashimoto disease develop antibodies against their own thyroid receptors which leads to hyper- or hypothyroidism, respectively. Although the population of antithyrotropin receptor antibodies is heterogeneous, most Graves antibodies bind the N-terminus of the receptor, whereas most Hashimoto antibodies bind the C-terminus of the receptor. In our study, panels of Graves and Hashimoto sera are tested a) for binding in a peptide-array to the set of overlapping 30-mers covering the hTSH-receptor; b) in a competition-assay in which the binding of biotinylated 40-mer TSH-peptides to hTSH-receptor is competed with Graves and Hashimoto sera. In this way, discontinuous binding sites are mapped.
After mapping the discontinuous binding sites, synthetic mimics are designed and synthesized. A primary strategy for synthesis of this kind of synthetic mimics is the synthesis of templates onto which the discontinuous epitope can be reconstructed. The use of templates facilitates the possibility to add various parts of the discontinuous epitope. In this way, hardly any specific binding information will be lost by a high flexibility of the peptide constructs. Attachment of peptides to template structures will closely mimic the native discontinuous epitopes. Recently, much progress has been made in this field. By using stable templates as a framework on which to couple recognition fragments, peptides can be obtained with desired activity.
Further Examples
Examples of Use:
Mapping Discontinuous Epitope on Human Tumor Necrosis Factor (hTNF) ( FIGS. 10-15 ).
The monoclonal antibody mAb-210 raised against hTNF was tested on linear and loop peptides (mAb-210 was bought from R&D Systems, MAB21O, clone 1825.12, through ITK Diagnostics Uithoorn, The Netherlands). Firstly, it was tested in Pepscan on all overlapping linear 12-mers covering hTNF. This resulted in a, minor peak around sequence IKSPCQRETPEG (SEQ ID NO: 2) ( FIG. 10 ). Secondly, it was tested in Pepscan matrix-scan on double 15-mer loop-loop peptides (as described in FIGS. 3 and 4 and explained through FIGS. 11-12 ). Two loop-regions were labeled: peptide sequence GQGCPSTHVLLT (SEQ ID NO: 65) (squares 65 to 67) and SAIKSPCQRE (SEQ ID NO: 28) (squares 92 to 96) ( FIGS. 13 , 14 ). In addition in various squares loop peptide spots were identified corresponding to sequence GQGCPSTHVLLT (SEQ ID NO: 65) (spots 65-67); SAIKSPCQRE (SEQ ID NO: 28) (spots 92-96) and KGDRLSAEINR (SEQ ID NO: 29) (spots 126-129) ( FIG. 14 ). These three regions, illustrated in FIG. 15 on the three-dimensional model of hTNF, are located on one side of the hTNF molecule and form one large discontinuous epitope region.
Identification of Synthetic Mimics of Antibodies (Binding Bodies) ( FIG. 16 ).
From six different antibodies, the HCDR3-region (complementary determining region three of the antibody heavy chain) was synthesized as synthetic loop-peptides. As an example, four different anti-lysozyme antibodies and two different anti-choriogonadotrophin antibodies were selected: 1fdl.pdb (D1.3), 1 mlb.pdb (D44.1), 3hfl.pdb (HyHel-5), 3hfm.pdb (HyHel-10) all anti-lysozyme, and 1qfw.pdb, two anti-human choriogonadotrophin, one anti-alpha and one anti-beta. The synthetic loop peptides were coupled to the minicards as described above. The three-dimensional coordinates (pdb-files) were extracted from the Protein Data Bank (PDB) at www.rcsb.org (RCSB, Research Collaboratory for Structural Bioinformatics) (Berman et al., 2000, The Protein Data Bank. Nucleic Acids Research, 28 pp. 235-242; Bernstein et al. 1977, The protein data bank: A computer-based archival file for macromolecular structures. J. Mol. Biol. 112 :535-542).
Together with each of the six peptides, 27 different other loop peptides were coupled to the minicard as described in FIG. 3B : thus, group-1 was a loop of HCDR3 of 1fdl.pdb coupled next to 27 different loops covering LCDR1, LCDR2 or LCDR3, group-2 was a loop of 1mlb.pdb coupled next to 27 different loops covering LCDR1, LCDR2 or LCDR3, etc. (LCDR, complementary determining region three of the antibody light chain). The 27 different loop peptides represented LCDR1, LCDR2 or LCDR3 of the same antibodies described above (1 fdl.pdb, 1 mlb.pdb, 3hfl.pdb, 3hfm.pdb or 1qfw.pdb).
The result is shown in FIG. 16 (6 groups with 27 loop-loop coupled peptides). The six loop-loop coupled peptides with the highest binding activity were: +LHGNYDFDGZ (SEQ ID NO: 32) +SESVDSYGNSFMQZ (SEQ ID NO: 46) (loop of HCDR3 of 3hfl.pdb and loop of LCDR1 1qfw.pdb, respectively) (see FIG. 16 ); +LHGNYDFDGZ (SEQ ID NO: 32) +RASESVDSYGNSFMQZ (SEQ ID NO: 49) (loop of HCDR3 of 3hfl.pdb and loop of LCDR1 1qfw.pdb, respectively); +LHGNYDFDGZ (SEQ ID NO: 32) +RASESVDSYGNSFZ (SEQ ID NO: 44) (loop of HCDR3 of 3hfl.pdb and loop of LCDR1 1qfw.pdb, respectively); +LHGNYDFDGZ (SEQ ID NO: 32) +ASESVDSYGNSFMZ (SEQ ID NO: 45) (loop of HCDR3 of 3hfl.pdb and loop of LCDR1 1qfw.pdb, respectively); +LHGNYDFDGZ,(SEQ ID NO: 32) +ASESVDSYGNSFZ (SEQ ID NO: 41) (loop of HCDR3 of 3hfl.pdb and loop of LCDR1 1qfw.pdb, respectively); +LHGNYDFDGZ (SEQ ID NO: 32) +LLVYYTTTLADGZ (SEQ ID NO: 51) (loop of HCDR3 of 3hfl.pdb and loop of LCDR2 1fdl.pdb, respectively).
The loop-loop peptide pair, +LHGNYDFDGZ (SEQ ID NO: 32) +SESVDSYGNSFMQZ (SEQ ID NO: 46) (loop of HCDR3 of 3hfl.pdb with loop of LCDR1 of 1qfw.pdb, respectively) that has the highest binding activity is indicated by an arrow ( FIG. 16 ). This loop-loop peptide pair is derived from an anti-lysozyme antibody and an anti-human choriogonadotrophin antibody. The results shown in FIG. 16 shows that particular pairs of synthetic CDRs show better binding to lysozyme than other pairs, especially group-C. Therefore, loop-loop combinations of synthetic loops representing different CDRs of (different) antibodies, not necessarily derived from the original antibody which in this example is an anti-lysozyme antibody, can be used to identify lead synthetic compounds that mimic antibodies.
Construction of a Double-Loop Mimic of a Discontinuous Epitope ( FIG. 17 ).
Two peptides that constitute two separate parts of a discontinuous epitope were coupled to the surface of a minicard as described above in the legend of FIG. 12 (cf FIG. 3A and FIG. 4 (example-4)). A cys(mmt) was coupled alone or in combination with a cys(trt) (in a 1:1 ratio) and/or val(mmt) (the cys and val in a 1:1, 1:3, 1:9 etc. ratio). In this way one peptide was coupled (squares A and C) or two peptides with increasing valines in between the cysteines were coupled (squares B and D) (cf FIG. 4B (example-4), FIG. 17 ). These four configurations were incubated with two different antibodies.
Antibody-1 recognized, when the individual loop peptides are coupled as a single loop, only loop peptide-2. Antibody-2 recognized, when the individual loop peptides are coupled as a single loops, only loop peptide-1. When the two loop peptides are combined, antibody-1 showed a higher binding activity with peptide-1 as coupled first. When the two loop peptides are combined, antibody-2 showed not a higher binding activity.
The results shown in FIG. 17 show that particular pairs of synthetic loops of a discontinuous epitope show improved binding to a particular antibody. Therefore, combinations of synthetic loops that are part of a discontinuous epitope can be used to identify lead synthetic compounds that mimic discontinuous epitopes. | The invention relates to the field of molecular recognition or detection of discontinuous or conformational binding sites or epitopes corresponding to a binding molecule, in particular, in relation to protein-protein, protein-nucleic acid, nucleic acid-nucleic acid or biomolecule-ligand interactions. The invention provides a synthetic molecular library allowing testing for, identification, characterization or detection of a discontinuous binding site capable of interacting with a binding molecule, the library having been provided with a plurality of test entities, each test entity comprising at least one first segment spotted next to a second segment, each segment having the capacity of being a potential single part of a discontinuous binding site. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation-in-Part of application Ser. No. 12/949,730, entitled “Alarm System Having An Indicator Light That Is External To An Enclosed Space For Indicating An Intrusion Into The Enclosed Space And A Method For Installing The Alarm System,” and filed on Nov. 18, 2010, incorporated herein by reference in its entirety.
This application is also related to application Ser. No. 12/949,734, entitled “Alarm System Having An Indicator Light That Is External To An Enclosed Space For Indicating The Time Elapsed Since An Intrusion Into The Enclosed Space And A Method For Installing The Alarm System,” and filed on Nov. 18, 2010, which is also a Continuation-in-Part of application Ser. No. 12/949,730, entitled “Alarm System Having An Indicator Light That Is External To An Enclosed Space For Indicating An Intrusion Into The Enclosed Space And A Method For Installing The Alarm System,” and filed on Nov. 18, 2010.
FIELD
The invention relates generally to systems and methods for intruder detection, and more particularly to notification of an intruder detection event.
BACKGROUND
Security systems for protecting buildings and other structures from intrusion are well known in the art. Such security systems generally include one or more alarms to notify others of an attempted or actual intrusion. These alarms can include audible signals and/or lights to indicate when a breach or attempted breach of a structure, such as the prying open of a door or window, has occurred. Such security systems can help to protect building owners and/or inhabitants from would-be intruders and actual intruders, such as burglars.
While many of these systems activate alarms to notify others of attempted or successful intrusions, these systems typically do not provide information as to whether there was merely an attempted intrusion, or an actual intrusion. Other systems may activate an alarm only to indicate an actual intrusion, but the alarm may deactivate or may be deactivated before the user of the system arrives upon the scene of the intrusion.
Furthermore, without sound, the alarms of known alarm systems are not easily noticeable from outside an enclosed space that was intruded upon. For example, the alarms of some systems are small, inconspicuous, and silent panels of information about an intrusion. Still other alarms that do provide sound do not clearly identify and locate the enclosed space that was intruded upon. Even though a loud alarm may be activated upon intrusion, the general location of the enclosed space being intruded upon may be unclear or ambiguous to observers outside the enclosed space.
SUMMARY
An alarm system with an indicator light that is external to an enclosed space for indicating an intrusion into an enclosed space and the specific location of the intrusion into the enclosed space, and a method of installing such a system, are claimed. For example, the alarm system will show that the intrusion occurred at a specific wall or corner of the enclosed space, and/or a specific door or a specific window of the enclosed space, and/or some other specific portion of the enclosed space.
The system can be purchased and installed inexpensively and easily, and it can provide a signal that does not expire over time, and is easily recognizable and locatable to the user of the system upon the user's arrival at the enclosed space or the structure. The signal indicates the specific location of an intrusion into the enclosed space, thereby providing information to others regarding where an intruder might be lurking and perhaps lying in wait, within the enclosed space, and/or possibly where the intruder might exit as well.
Upon detecting an intrusion into the enclosed space, the alarm system employs an indicator light that is located within an outer perimeter zone that surrounds the enclosed space. Upon activation, the indicator light emits light that extends beyond the outer perimeter zone of the enclosed space as an intrusion alert, thereby reducing the need of a user to enter the outer perimeter zone of the enclosed space to determine the specific location of the intrusion. The alert is conspicuous and easily recognizable to anyone who approaches the outer perimeter zone of the enclosed space for which the external light alert is activated. An indicator light alarm is typically also easier for people to trace to its source than is a sound alarm, particularly if the enclosed space is situated close to other enclosed spaces with which it could be confused. The enclosed space can be a building, or a particular section or room of a building, for example.
The alarm system provides alerts regarding the specific location of an intrusion into an enclosed space and/or structure, in addition to alerting a user of an intrusion event generally. The alert provides specific location information regarding only successful intrusions into an enclosed space, as opposed to mere attempted intrusions.
The indication of the specific location of an intrusion into an enclosed space is information that can provide an observer with insight as to the nature of the intrusion, without requiring that the observer enter the enclosed space, or even enter the outer perimeter zone of the enclosed space. An alert indicating the specific location of an intrusion can therefore be helpful in a variety of ways, such as enhancing the decision-making process for the user or others investigating the intrusion, regarding how they would respond to the alert.
For example, information regarding the specific location of an intrusion can affect the decision-making process of someone investigating the intrusion, such as the police, on how to further investigate or respond to the intrusion.
The present alarm system having an indicator light that is external to an enclosed space for indicating the location of an intrusion into an enclosed space, can benefit from use with the invention disclosed in patent application Ser. No. 12/949,734, entitled “Alarm System Having An Indicator Light That Is External To An Enclosed Space For Indicating The Time Elapsed Since An Intrusion Into The Enclosed Space And A Method For Installing The Alarm System,” and filed on Nov. 18, 2010.
In one embodiment, the invention is an alarm system for providing an indication of a specific location of an intrusion into an enclosed space, the enclosed space being surrounded by an outer perimeter zone, the indication enabling an observer situated outside the outer perimeter zone to learn the specific location of the intrusion, the alarm system comprising: at least one interior sensor located within an enclosed space, the interior sensor being configured to generate a specific intrusion location signal in response to an intrusion into the enclosed space; a light control system responsive to the specific intrusion location signal, the light control system being configured to control light emitted from an indicator light so as to indicate the specific location of the intrusion; and an indicator light capable of indicating the specific location of the intrusion, the indicator light being responsive to the light control system, the indicator light being located within an outer perimeter zone of the enclosed space, the indicator light being capable of emitting light that is visible from outside the outer perimeter zone of the enclosed space.
In another embodiment, the invention is a method of installing an alarm system for providing an indication of a specific location of an intrusion into an enclosed space, the enclosed space being surrounded by an outer perimeter zone, the indication enabling an observer situated outside the outer perimeter zone to learn the specific location of the intrusion, the alarm system comprising: mounting at least one interior sensor located within an enclosed space, the interior sensor being configured to generate a specific intrusion location signal in response to an intrusion into the enclosed space; installing a light control system responsive to the specific intrusion location signal, the light control system being configured to control light emitted from an indicator light so as to indicate the specific location of the intrusion; and mounting an indicator light capable of indicating the specific location of the intrusion, the indicator light being responsive to the light control system, the indicator light being located within an outer perimeter zone of the enclosed space, the indicator light being capable of emitting light that is visible from outside the outer perimeter zone of the enclosed space.
In some embodiments, the at least one interior sensor is capable of detecting intrusion into the enclosed space in proximity to a peripheral window of the enclosed space, a peripheral door of the enclosed space, a chimney of the enclosed space, and/or a general internal area of the enclosed space. In some embodiments, the indicator light is capable of directing light towards the specific location of the intrusion. In other embodiments, the indicator light is capable of directing light towards at least one of an external side of the enclosed space, an outer corner of the enclosed space, a door, a window, and/or a chimney. In other embodiments, the indicator light is located in immediate proximity to the specific location of the intrusion. In some of these embodiments, indicator light surrounds the specific location of the intrusion.
In some embodiments, the light is a focused light beam, a beacon light, a blinking light, and/or a rotating light. In other embodiments, the indicator light is a light display that is capable of producing a readable output of the specific location of the intrusion.
In some embodiments, the specific intrusion location signal is also received on a mobile device. In other embodiments, the system can be activated by a keypad installed near an entrance of the enclosed space, a keypad installed within the outer perimeter zone of the enclosed space, a manual key configured to fit a manual lock, a remote control device dedicated to activation of the system, a personal mobile communication device.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood by reference to the detailed description, in conjunction with the following figures, wherein:
FIG. 1A is a block diagram showing the main elements of an embodiment of the alarm system;
FIG. 1B is an elements diagram showing the interaction between the main elements of an embodiment of the alarm system wherein the main elements are hard wired together;
FIG. 1C is an elements diagram showing the interaction between the main elements of an alternative embodiment of the alarm system wherein the main elements are connected together via wireless communication;
FIG. 2A is an aerial view of a house equipped with an installed version of an embodiment of the alarm system, showing the light output indicating a specific location of an intrusion;
FIG. 2B is an aerial view of a house equipped with an installed version of the embodiment shown in FIG. 2A , showing the light output indicating a more general location of an intrusion;
FIG. 3 is an aerial view of a house equipped with an embodiment of a combination of indicator lights of the alarm system;
FIG. 4 is an aerial view of a house equipped with an alternative embodiment of a combination of indicator lights of the alarm system;
FIG. 5 is an aerial view of a house equipped with another alternative embodiment of a combination of indicator lights of the alarm system;
FIG. 6 is side view of a house equipped with another alternative embodiment of a combination of indicator lights of the alarm system;
FIG. 7 is an illustration of a component of an embodiment of the alarm system, wherein a specific intrusion location message is produced on a mobile device;
FIG. 8 is an illustration of a room within a building employing an embodiment of the alarm system;
FIG. 9A depicts a keypad configured to control activating system for an embodiment of the alarm system;
FIG. 9B depicts a manual key and lock configured to control an activating system for an embodiment of the alarm system;
FIG. 9C depicts a remote dedicated device and receiver configured to control an activating system for an embodiment of the alarm system;
FIG. 9D depicts a personal mobile device and receiver configured to control an activating system for an embodiment of the alarm system; and
FIG. 10 is a flowchart depicting a sequence of events related to an embodiment of the alarm system in use.
DETAILED DESCRIPTION
FIG. 1A is a block diagram showing the main elements of an embodiment of the alarm system. In the embodiment represented by the diagram of the system elements 100 , several interior sensors are placed within an interior space of a building, which in this case is a house.
The enclosed space to be equipped with the alarm system can be any building or enclosed portion of a building (such as a section or room of the building) for which a user of the system wishes to receive notice of the intrusion by another into the enclosed space. Such enclosed space can include rooms, sections, levels, or entire internal areas of buildings such as houses, apartments, schools, dorm rooms, office buildings, factories, or any other buildings apparent to one of ordinary skill in the art of intrusion alert systems.
In the embodiment shown, the sensors are placed in such a manner so as to detect intrusion of the building. In alternative embodiments, sensors can be strategically placed so as to detect intrusion of a certain particular enclosed space of the building, such as a particular room or group of adjacent rooms, or an entire floor level of the building, for example. The exemplary sensors shown include a door sensor 102 , a window sensor 104 , a chimney sensor 106 , and an internal area sensor 108 .
Sensors can be placed in proximity to access points to the building or an enclosed portion of the building, so as to detect intrusion of the enclosed space through the access point. Such access points which the sensor may be placed near can include a door 102 , window 104 or chimney 106 , for example. Another sensor can be placed within a general internal area of an enclosed space 108 , so as to detect movement inside the enclosed space, or so as to employ any other means of detecting intrusion apparent to one of ordinary skill in the art of intrusion detection.
The sensors can be any kind of sensor configured to detect intrusion, such as a heat sensor or infrared sensor, for example. One skilled in the art will appreciate and readily acknowledge other possible sensors which can be used. If an intrusion occurs, a sensor will detect the intrusion and send a specific intrusion location signal to a control unit 110 . The control unit 110 will send the specific intrusion location signal to an indicator light located outside the enclosed space and in an outer perimeter zone of the enclosed space. The control unit 110 can serve as a light control system, configured to control the light so as to indicate the location of intrusion.
The indicator light will emit light so as to indicate that an intrusion has occurred, and to indicate the location of the intrusion. Other sensors positioned and configured to detect movement within the enclosed space for which intrusion is to be detected will be readily apparent to one ordinarily skilled in the art of intrusion detection. A light control system controls light emitted by the indicator light so as to indicate the location of the intrusion.
FIG. 1B is an elements diagram showing the interaction between the main elements of an embodiment of the alarm system, wherein the main elements are hard wired together with electrical wiring. A house 120 equipped with an embodiment of the alarm system is shown, containing a door sensor 122 , window sensor 124 , chimney sensor 126 , and internal area sensor 128 .
As depicted in this diagram, the sensors are hard wired to a common control unit 130 , which in turn is in hard wire communication with an indicator light 132 . In the embodiment shown, the control unit 130 is located outside the structure of the house 130 . Upon receiving a specific intrusion location signal from any of the sensors, the control unit 130 can propagate the signal to the indicator light 132 located in the outer perimeter zone of the enclosed space, which emits light that is visible beyond the outer perimeter zone of the enclosed space, thereby alerting others to an intrusion and the location of the intrusion. In this embodiment, the indicator light 132 is located outside the house but within a curtilage of the house 120 , and produces light that is visible beyond the curtilage.
In the embodiment shown, the indicator light 132 emits a light beam 133 that is directed towards the location of the intrusion, so as to indicate the location of the intrusion. In this example, the light 133 is directed towards the front door of the house, so as to indicate that the house was intruded via the front door.
FIG. 1C is an elements diagram showing the interaction between the main elements of an alternative embodiment of the alarm system wherein the main elements are connected together via wireless signaling. A house 120 equipped with an embodiment of the alarm system is shown, containing a door sensor 122 , window sensor 124 , chimney sensor 126 , and internal area sensor 128 .
As depicted in this diagram, the sensors are linked via wireless connection to a common control unit 140 , which in turn is in wireless communication with an indicator light 132 . In the embodiment shown, the control unit 140 is located inside the structure of the house 120 . Upon receiving a specific intrusion location signal from any of the sensors, the control unit 130 can propagate the signal to the indicator light 132 located in the outer perimeter zone of the enclosed space, which emits light that is visible beyond the outer perimeter zone of the enclosed space, thereby alerting others to an intrusion and the location of the intrusion. In this embodiment, the indicator light 132 is located outside the house but within a curtilage of the house 120 , and produces light that is visible beyond the curtilage.
In the embodiment shown, the indicator light 132 emits a light beam 133 that is directed towards the location of the intrusion, so as to indicate the location of the intrusion. In this example, the light 133 is directed towards the front door of the house, so as to indicate that the house was intruded via the front door.
FIG. 2A is an aerial view of a house equipped with an installed version of an embodiment of the alarm system, showing the light output indicating a specific location of an intrusion. In this embodiment, the house 200 is equipped with an indicator light 202 that emits a continuous light beam 203 .
In the embodiment shown in this figure, the light beam 203 is a window light 113 directed at a window through which the house has been intruded upon. Therefore, in this embodiment the indicator light 202 indicates the location of intrusion by directing the light beam 203 towards the specific intrusion location.
FIG. 2B is an aerial view of a house equipped with an installed version of the embodiment shown in FIG. 2A , showing the light output indicating a more general location of an intrusion. In this embodiment, the house 200 is equipped with an indicator light 202 that emits a continuous light beam 204 .
In the embodiment shown in this figure, the light beam 204 is a general area light 115 directed at a corner section of the house. The light beam 204 indicates that intrusion occurred within one of the entry points illuminated by the light beam 204 , including a front-facing window and a side-facing window. Such general information can be the result of an internal area sensor 108 , for example. The specific intrusion location signal will therefore provide more general information, than a specific intrusion location signal sent by a sensor dedicated to detecting intrusion of a specific access point, such as the embodiment shown and discussed in FIG. 2A .
FIG. 3 is an aerial view of a house equipped with an embodiment of a combination of indicator lights of the alarm system. A house 200 is equipped with an indicator light 202 that emits a continuous light beam 300 . In addition, this embodiment also includes a light display 302 capable of producing a readable output of the location of the intrusion, wherein the light control system is configured to control the readable output that is produced by the light display 302 . In the embodiment shown, the light display 302 is located on a wall near a doorway into the house 200 . The light display 302 is indicating that intrusion occurred through a kitchen window of the house 200 .
FIG. 4 is an aerial view of a house equipped with an alternative embodiment of a combination of indicator lights of the alarm system. A house 200 is equipped with an indicator light 400 that emits a beacon light 400 , such as light emitted omni-directionally from a bulb, as opposed to a focused beam. The beacon light 400 can be light of continuous output, or alternatively, it can be light of non-continuous output, such as a blinking light. The beacon light 400 is installed at the top of the house 200 .
In addition, this embodiment also includes a light display 402 capable of producing a readable output of the location of the intrusion, wherein the light control system is configured to control the readable output that is produced by the light display 402 . In the embodiment shown, the light display 402 is located on a wall around the corner from a doorway into the house 200 . The light display 402 is indicating that intrusion occurred through a kitchen window of the house 200 .
FIG. 5 is an aerial view of a house equipped with another alternative embodiment of a combination of indicator lights of the alarm system. In this embodiment, the house 200 is equipped with a rotating light beam 500 , which is installed at the top of the house 200 . The light beam 500 is projected substantially horizontally from a rotating light source. In the embodiment shown, the rotating light beam 500 is a focused light beam which rotates about the vertical axis of its light source. This rotating light 600 can potentially alert others in all directions beyond the curtilage of the house 400 , potentially including those located within neighboring dwellings.
In addition, this embodiment also includes a light display 500 capable of producing a readable output of the location of the intrusion, wherein the light control system is configured to control the readable output that is produced by the light display 500 . In the embodiment shown, the light display 500 is located on a walkway towards a doorway of the house 200 . The light display 500 is indicating that intrusion through a kitchen window of the house 200 .
FIG. 6 is side view of a house equipped with another alternative embodiment of a combination of indicator lights of the alarm system. In the embodiment shown, a house 600 includes a light display 602 comprised of a plurality of lights surrounding the perimeter of a possible location of intrusion. In the embodiment shown, a series of lights surround the perimeter of a window. The lights are illuminated, thereby alerting others that the house 200 has been intruded upon, via the window that is illuminated by the light display 602 .
FIG. 7 is an illustration of a component of an embodiment of the alarm system, wherein a specific intrusion location message is produced on a mobile device. In the embodiment shown, a mobile device 700 receives a specific intrusion location message 702 , in addition to an indicator light signal being projected from the outer perimeter zone of the enclosed space with which the indicator light is associated. Such a mobile device specific intrusion location message 702 can supplement the indicator light, providing an enhancement to the alarm system. For example, if an intrusion is detected, the alarm system can alert those for whom the intruded enclosed space is in sight. In addition, a user of the alarm system can receive an alert 702 on their mobile device 700 , which can be an important and useful supplemental alert if and when they are not near or approaching the enclosed space. In the embodiment shown, the specific intrusion location message 702 indicates that intrusion occurred through a kitchen window of the house.
FIG. 8 is an illustration of a room within a building employing an embodiment of the alarm system. In this embodiment, the alarm system is configured to alert others of the location of an intrusion into an enclosed space within a building, in this instance the enclosed space being a room of a house. In this embodiment, a room 800 adjacent to the intruded room is equipped with an indicator light 802 . The indicator light in this example is a light display 802 which indicates readable output concerning the location of the intrusion.
The light display 802 shown is capable of producing a readable output of the location of the intrusion, wherein a light control system is configured to control the readable output that is produced by the light display. In the embodiment shown, the light display 802 is located above a doorway 804 which leads from the adjacent room 800 into the intruded room. The light display 802 is indicating that intrusion occurred through the door.
The indicator light 802 is located within the outer perimeter zone of the room equipped with the alarm system, and the light display 802 is visible and readable beyond the outer perimeter zone of the room equipped with the alarm system. For example, someone in the adjacent room 800 could easily see the light display and read the output. In some embodiments, several such indicator lights 802 may be placed at various locations within the outer perimeter zone of the enclosed space equipped with the alarm system, so as to alert others in various neighboring rooms, for example.
If an unexpected intrusion occurs in one room, the indicator light 802 can alert others in adjacent rooms 800 of the intrusion, for example. In other embodiments, the enclosed space under surveillance may be a group of rooms, or some other portion of a building, for example. The indicator light 802 is located in the outer perimeter zone immediately outside the enclosed space under surveillance. In this case, the outer perimeter zone includes the doorway 804 and wall of an adjacent room 800 . The indicator light 802 is therefore mounted on the adjacent wall of the doorway 804 connecting the intruded room with the adjacent room 800 .
The alarm system can be activated through a variety of techniques, some of which are discussed explicitly in this specification, while still others will be readily apparent to one of ordinary skill in the art. FIG. 9A depicts a keypad 900 configured to control an activating system in an embodiment of the alarm system. Such a keypad can be installed on an outer wall of a house, near an entrance into the house for example, or somewhere near the house and within the curtilage of the house, for example. The keypad is connected to and capable of communicating with an activator 902 which can activate the system.
FIG. 9B depicts a manual key and lock configured to control an activating system for an embodiment of the alarm system. In this embodiment, a manual key 904 can fit into a manual keyhole 906 , and whereupon the key 904 is inserted into the keyhole 906 and turned, the alarm system can be activated and/or deactivated via communication with an activator 902 .
The alarm system can also be activated via remote devices. FIG. 9C depicts a dedicated remote device 908 and a receiver 910 , which in combination are configured to control an activating system in an embodiment of the alarm system. A user of the system can activate the system using a remote control 908 which communicates with a receiver 910 , which in turn is linked to an activator 902 . FIG. 9D depicts a personal mobile device 912 and reception tower 913 in communication with a receiver 914 , which in turn is linked to an activator 902 and configured to control an activating system for an embodiment of the alarm system. Still other activation systems will be readily apparent to one of average skill in the art.
FIG. 10 is a flowchart depicting a sequence of events related to an embodiment of the alarm system in use, in relation to a structure. First, a potential intruder attempts to breach and/or intrude a structure or other enclosed space equipped with the system 1000 , with intent to intrude the structure or enclosed space. In this embodiment, the entire structure is equipped with the system, while in alternative embodiments only a sub-enclosure, such as a room within the structure, might be so equipped.
If the intruder succeeds in intruding the structure 10002 , an interior sensor will detect the intrusion 1004 and generate an intrusion signal 1006 , which in the present invention is a specific intrusion location signal indicating the location of the intrusion. If the system includes for the specific intrusion location signal to be sent to a user's mobile device 1008 , then the mobile device can be alerted 1010 . The specific intrusion location signal is sent to an indicator light 1012 , which then activates and outputs an alarm light 1014 upon receiving the information regarding the intrusion time signal. The indicator light indicates the location of intrusion. This completes the main operation of the system 1016 .
Other modifications and implementations will occur to those skilled in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the above description is not intended to limit the invention except as indicated in the following claims. | An alarm system for indicating the specific location of an intrusion into an enclosed space, as well as a method for installing the alarm system, are disclosed. The intrusion causes illumination of an indicator light outside the enclosed space and within the outer perimeter zone of the enclosed space, thereby indicating the specific location of the intrusion. At least one interior sensor located within the enclosed space generates a specific intrusion location signal in response to movement therein. A control system responsive to the specific intrusion location signal causes the indicator light to emit light that is visible from outside the outer perimeter zone of the enclosed space. The emitted light can indicate the specific location of an intrusion by directing light towards the specific intrusion location, and/or by surrounding the specific intrusion location, and/or by activating a light display that produces readable output of the specific intrusion location. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/353,679 filed Jun. 11, 2010, which is incorporated herein in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present invention relates generally to a wind turbine system for generating electricity and more specifically to a wind turbine system for generating electricity that includes two up-wind rotors and one down-wind rotor structure.
BACKGROUND OF THE INVENTION
[0003] Existing large scale wind turbine systems for utilizing wind energy to generate electricity have certain disadvantages.
[0004] For example, when the diameter of a wind turbine rotor exceeds twelve (12) meters, the wind input at its center has no effect on the rotation of the rotor thereby creating “an aerodynamic dead zone.” Accordingly, a large scale wind turbine system has its corresponding large aerodynamic dead zone.
[0005] Another disadvantage involves the coupling the rotational forces of two or more rotors with different RPMs, where the force generated is limited by the gear ratio of each rotor's RPM and the total rotational force is decreased by the drag force created between the rotors of different tip speed rotor.
[0006] Furthermore, when the input wind speed is above the rated wind speed, a mechanical stress can be created that exceeds the point where the wind turbine system can operate safely without breaking.
[0007] Another challenge to a developer of a wind turbine system is avoiding aerodynamic interference between the counter-rotating rotors.
SUMMARY OF THE INVENTION
[0008] Accordingly, it is an object of the present invention to provide an improved wind turbine system for generating electricity.
[0009] Another object of the present invention is to provide a high speed small control rotor placed in front of auxiliary rotor in an up-wind position to create an aerodynamic dead zone-less system.
[0010] The control rotor increases the rotational speed of both auxiliary rotor in the up-wind position and main rotor in the down-wind position during low wind speed as well as during rated wind speed.
[0011] Another object of the present invention is to provide a flexible electromagnetic torque coupling where the rotational force of two or more rotors of different RPM is not limited by the gear ration of the RPMs of each rotors.
[0012] When the tip speed ratio of each rotors are different, rotation of one rotor acts as a drag force on each other thereby decreasing the total rotational force. Coupling of electromagnetic torque of the current invention is flexible and is not dependent on the gear ratio of the rotors and the drag force created by the different tip speed is avoided.
[0013] Further, the present invention is can operate under variable system capacity (i.e. variable load) corresponding to different input wind energy.
[0014] The variable system capacity improves the generators efficiency through the load share ratio of a large-sized generator in accordance with the magnitudes of the energy caused by the variation of input wind speed.
[0015] Other objects and the scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION THE DRAWINGS
[0016] The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not (imitative of the present invention, and wherein:
[0017] FIG. 1 is a perspective view of a wind turbine system embodying the present invention.
[0018] FIG. 2 is a side view of the annual stream tube depicting in detail the present invention.
[0019] FIG. 3 is a side view of gear box with its twins generators.
[0020] FIG. 4 is a detailed view of the section along the A-A′ or C-C′ line of the dual input gear box shown in FIG. 7 .
[0021] FIG. 5 is a side view of the auxiliary generator.
[0022] FIG. 6 is a cross sectional view along B-B′ line shown in FIG. 5 .
[0023] FIG. 7 is a side view of the dual axis inputs gear box.
[0024] FIG. 8 is a detailed view of the section along the D-D′ line shown in FIG. 7 .
[0025] FIG. 9 is a side view of the rotor hub, the control rotor, and the auxiliary rotor.
DETAILED DESCRIPTION OF THE INVENTION
Triple Rotor System
[0026] FIG. 1 shows overall system of the present invention. The present invention can be divided into seven parts. Part 1 in a down wind position comprises of main rotor 11 (“MR”) and its hub 1 . Part 2 comprises of a gear box 2 which increases the speed of MR 11 . Part 3 comprises of a gear box 3 which combines the rotational forces of control rotor 81 (“CR”), auxiliary rotor 71 (“AR”) and MR 11 .
[0027] Part 4 comprises of twin generators 4 , 4 - 1 . Part 5 comprises of the auxiliary generator 5 which combines rotational forces of CR 81 and AR 71 . Part 6 comprises of dual axis input gear box 6 which combines the rotational forces of CR 81 and AR 71 . Part 7 comprises of CR hub 7 and AR hub 8 in a up wind position.
Aerodynamic Dead Zone
[0028] A wind turbine obtains its power input by converting the force of the wind into a torque on the rotor blades. The amount of energy which the wind transfers to the rotor depends on the density of the air, the rotor area, and the wind speed.
[0029] The kinetic energy of a moving body is proportional to its mass or weight. The kinetic energy in the wind thus depends on the density of the air. In other words, the “heavier” the air, the more energy is received by the turbine.
[0030] At normal atmospheric pressure and at 15 Celsius air weighs some 1.255 kg per cubic meter. The greater the diameter of a wind turbine rotor, the greater the effect of tip speed to limit and reduce revolutions per minute (“RPM”). This creates an “aerodynamic dead zone” in part of the hub where no lift force is generated due to its low RPM.
[0031] More specifically, the aerodynamic dead zone is about 30% of the blade from the center axis, which no wind energy can be converted into mechanical energy.
[0032] Fast spinning CR 81 is placed directly in front of AR 71 blade extender hubs so that the wind inputs into this aerodynamic zone of the AR blades extenders is diverted outside of the dead zone thereby increasing the air density and directing this increased air density to the tips of the AR blade where the sweeping speed is the greatest.
[0033] FIG. 2 shows an air stream line 107 of AR 71 according to Betz's disk analogy model. Then an annular stream tube 104 with increased air density is created between an air stream line 107 of AR 71 and air stream line 106 of MR 11 . Then, this increased air density of annular stream tube 104 is applied to the outer tips of MR 11 blades.
[0034] This phenomenon depends on the diameter of CR 81 , the distance between CR 81 and AR 71 , the diameter of AR 71 , and the distance between AR 71 and MR 11 . This phenomenon has been tested and proved numerous times with smaller model in a experimental field tests as well as actual sized scaled model field tests.
[0035] FIG. 1 shows the direction of rotation of each part indicated by the big arrows, and the direction of rotational force indicated by the small arrows. Keeping CR 81 , AR 71 and MR 11 rotational force combining gear box 3 as the point of reference, will describe in order the upwind portion starting with FIG. 9 toward the gear box 3 , then downwind portion starting with MR 11 towards the gear box 3 .
[0036] When there is wind speed 1.8-2.2 m/s, CR 81 rotates in the direction as shown in FIG. 1 . As shown in FIG 9 , when CR 81 rotates, it causes the hollow shaft 76 - 3 , the coupling plate 76 - 4 and the spline coupling 76 - 2 to rotate in the same direction.
[0037] Then in FIG 7 , this rotational force of CR 81 further extends and rotates rotational shaft 76 and spline coupling 76 - 1 . This rotational force is transferred then to the CR-AR dual axis input gear box 6 where it rotates the input rotation shaft 66 and the Input member planet gear carrier 67 .
[0038] As shown in FIG. 8 , the second sun gear 62 - 2 attached to the input member planet gear carrier 67 will also rotate. This will rotate the second planet gears 62 - 3 and the second ring gear 62 - 4 in the opposite direction.
[0039] As CR 81 starts to rotate the second sun gear 62 - 2 attached to the input member planet gear carrier 67 also rotates. This sun gear 62 - 2 rotation will cause to counter rotate the second ring gear 62 - 4 which is attached to the second ring gear cylinder 62 - 5 . Since the second ring gear cylinder 62 - 5 is coupled to AR 71 , CR 81 rotation will eventually make AR 71 rotating in the opposite direction of CR 81 .
[0040] Hence, the rotational force of CR 81 transfers to AR 71 adds to the direct natural wind input and assist AR 71 rotate more easily. The inverse rotational forces of these two rotors CR 81 and AR 71 creates the air stream tube 105 as shown in FIG. 2 with its increased the air density. This increased air density is directed at the tips of MR 11 and assist MR 11 rotate even at a low wind speed.
Dual Axis Inputs GearBox
[0041] As shown in FIG. 7 , when the difference in the rotational force of CR 81 and AR 71 spinning in opposite direction is inputted into the dual axis inputs gearbox 6 , then the ring gear 63 and the planet gear carrier 67 rotating in opposite direction will rotate the sun gear 61 in clockwise direction according to the given gear ratio.
[0000] CR 81 Input RPM: N1 X {1+(ZR1/ZS1)} (1)
[0000] AR 71 Input RPM: N2 X (ZR2/ZS2) (2)
[0000] Total RPM of Sun Gear output shaft 61 - 1 :
[0000] Tn1n2=[N1 X {1+(ZR1/ZS1)}]+N2 X (ZR2/ZS2) (3)
[0000] ZS1: number of first sun gear teeth
[0000] ZS2: number of second sun gear teeth
[0000] ZR1: number of first ring gear teeth
[0000] ZR2: number of second ring gear teeth
[0042] Above equation ( 1 ) only applies when the RPMs of the sun gear 61 and the ring gear 63 , and the input torque are same. Based on the characteristic of dual axis gearbox 6 , the larger torque AR 71 s rotational speed and CR 81 s rotational speed are determined by the the gear ratio of the second sun gear 62 - 2 and the second ring gear 62 - 4 .
[0043] In order to make CR 81 and AR 71 s tip speed ratio the same, the size of the CR 81 , and the gear ratio of the second sun gear 62 - 2 and the second ring gear 62 - 4 are adjusted so that the speed of AR 71 rotation is optimized to increase the efficiency of the system at the dual axis inputs gearbox 6 .
[0044] However, since CR 81 performs the pitch control at the wind speed greater than the rated wind speed, rotational speed of CR 81 acts as a drag force on the rotational speed of AR 71 through the second planetary gear assembly shown in FIG. 8 of the dual axis inputs gearbox 6 .
[0045] This slows down the rotational speed of the rotor 53 of auxiliary generator 5 , and weakens the electromagnetic torque of the rotating stator 51 thereby decreasing the rotational speed of the MR 11 allowing the overall system to operate more safely.
Electromagnetic Torque
[0046] The rotational force of CR 81 and AR 71 combined at the dual axis inputs gearbox 6 is transferred via the high speed output shaft 61 - 1 , the connection plate 62 - 6 , and the connection plate 59 - 1 of the auxiliary generator 5 to the rotor 52 attached to the rotor shaft 53 thereby rotating the rotor 52 clockwise as shown in FIG. 6 and generating rated RPM in accordance with the pole numbers of the auxiliary generator 5 .
[0047] Then the electromagnetic coupling torque of the load is created. This causes the slow rotating stator 51 that is rotating in the same direction as the high speed rotating rotor 52 to rotate in the same direction, thereby increasing the rotational speed of the MR 11 .
[0048] This mechanism is summarized as follows:
[0000] Torque of CR 81 +Rotational Torque of AR 71 =generation power of the auxiliary generator 5
[0000] Electromagnetic torque from the load between the rotor 52 of the auxiliary generator 5 and the rotation stator 51 +rotational torque of MR 11 =generation power of the twins generators 4 , 4 - 1
[0049] The general principle behind the generators is based on the rotational force created between the stator and the rotor. Energy is generated when one or other rotates or when they rotate in opposite direction to one another.
[0050] However, the generator of the present invention generates energy even though both the rotor and the stator are rotating in the same direction. The number of poles of auxiliary generator has a prescribed RPM's.
[0051] It is the difference of this prescribed RPM's in effect acts as though either the stator 51 or the rotor 52 is in a fixed position thereby generating energy. If the RPM of the rotor 52 is defined as V1, RPM of the stator 51 rotating in same direction is defined as V2, and the prescribed RPM of the number of poles of the auxiliary generator 5 is defined as V0:
[0000] V0=V1−V2 (4)
[0052] RPM of V2 is accelerated by predetermined number of rotation of MR 11 's gearbox 2 . This RPM V2 inputs to a horizontal input shaft 39 of CR-AR rotational force combining gearbox 3 which is coupled to the rotation stator 51 . The energy generated from the auxiliary generator 5 is drawn out by the slip ring 54 . And this energy also rotates the bearings 58 , 55 which are mounted on the drive train pad 17 of the auxiliary generator 5 .
Total Rotational Force Integrating Gearbox
[0053] Rotational force generated by MR 11 and rotational force generated by the electromagnetic coupling torque created between rotor 52 and stator 51 of the auxiliary generator 5 by the load combined at the gearbox 3 . As shown in FIG. 1 , the rotational force of MR 11 is inputted into the gearbox 2 and generates energy based on a prescribed number of rotation.
[0054] In FIG. 5 , the rotational force generated by the combined electromagnetic coupling torque in the auxiliary generator 5 is transmitted via rotation shaft 56 and rotational plate 57 . Then it is sent to the rotational force connection plate 39 - 2 . Finally, these rotational force are combined at the horizontal input shaft 39 of the twins planetary gear of the gearbox 3 as shown in FIG. 3 .
[0055] Such sun gear and planetary gear assembly is known from the Applicant's U.S. Pat. No. 5,876,181, the contents of which are hereby incorporated in their entirety.
[0056] In FIG. 3 , the right-sided bevel gear 37 - 1 and left-sided bevel gear 38 - 1 rotates in the direction as indicated by the arrow. This causes the bevel gear 38 and the bevel gear 37 to rotate in opposite direction to one another.
[0057] Further, the bevel gear 38 is attached to the planet gear input shaft 36 on each twin planetary gear system. In each twin planetary gear system, the planet gear carrier 36 - 1 , the ring gear cylinder input shaft 35 and the ring gear cylinder 35 - 1 are attached to the ring gear 33 .
[0058] The ring gear 33 rotates in the opposite direction to the planet gears 32 as indicated by the arrows as shown in FIG. 4 thereby obtaining the gear ratio and the RPM as follows:
[0000] Z0={(1+ZR/ZS)+(ZR/ZS)}X n (5).
[0000] Z0 is the total output RPM
[0000] ZS is the number of sun gear teeth
[0000] ZR is the number of ring gear teeth
[0000] n is the input RPM
Variable Load Capacity System
[0059] The sun gear 31 accelerated to the rated output RPM rotates the output shaft 34 , thereby rotating the twin generators 4 , 4 - 1 . The gearbox 3 is a twin planetary gearbox system with symmetrical gearbox on either side of horizontal input shaft 39 .
[0060] The rotational forces of MR 11 , AR 71 and CR 81 are combined at this horizontal input shaft 39 . Depending on the variable forces of the input wind energy, one or both generators can be operated.
[0061] When the input wind energy from cut-in wind speed is up to 10 m/s, about 60% of the full system is operated where the auxiliary generator 5 and the twin generator 4 operates. When the wind speed ranges from 10.1 m/s to rated wind speed of 12 m/s, the twins generator 4 - 1 is added to the auxiliary generator 5 and the twin generator 4 .
[0062] Accordingly, the present invention includes the auxiliary generator's electromagnetic coupling torque, the triple rotor-irtegrating force, and aerodynamic dead zone-less wind power generating system, thereby increasing the system's potential capacity to a maximum degree and providing high efficiency aerodynamic operation.
[0063] No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the sprit and scope of the claims appended hereto. | The present invention relates to an aerodynamic dead zone-less triple-rotor integrated wind power driven system wherein control rotor 81 disposed at up-wind is rotated at a high speed. It induced the air flowing into the hub of extenders 71 of the auxiliary rotor 71 to the outside of the extenders 71 - 1 of the auxiliary rotor 71 , thereby forming an aerodynamic annular stream tube zone and increasing the air density therein, the main rotor 11 disposed at down-wind, is aerodynamically accelerating and improving the system efficiency. In addition, the rotor 52 and stator 51 of the electromagnetic attraction dragging rotational torque of the auxiliary generator by the load assists to rotate main rotor 11 , thereby the triple rotors integrating rotational torque generates the twin generators 4 and 4 - 1 ″ of the wind turbine. | 8 |
FIELD OF THE INVENTION
The field of this invention is lock open devices for sub-surface safety valves (SSSV) and related techniques for gaining access to the pressurized control system for subsequent operation of an inserted replacement.
BACKGROUND OF THE INVENTION
SSSVs are normally closed valves that prevent blowouts if the surface safety equipment fails. Conditions can arise where the SSSV fails to function for a variety of reasons. One solution to this situation has been to lock open the SSSV and to gain access into the pressurized control system that is used to move the flow tube to push the flapper into an open position against the force of a closure spring that urges the valve into a closed position. Thereafter, a replacement valve is delivered, normally on wireline, and latched into place such that the newly formed access to the control system of the original valve is now straddled by the replacement valve. This allows the original control system to be used to operate the replacement valve.
There have been several variations of lock open devices in the past. U.S. Pat. No. 4,577,694 assigned to Baker Hughes teaches the use of a flapper lock open tool (FLO) which delivers a band of spring steel to expand when retaining sleeves on the FLO tool are retracted. The tool latches inside the SSSV and with the flow tube in the flapper-closed position the band is released. This design offered the advantages of the lockout device not being integral to the SSSV. Instead it was only introduced when needed through a wireline. Another advantage was that the release of the band did no damage to the SSSV or the FLO tool. The band expanded into a recessed area so as to allow full-bore through-tubing access. The flow tube did not have to be shifted so that no spring forces acting on the flow tube had to be overcome to actuate the FLO tool. Subsequently, when the SSSV was retrieved to the surface, the band was easily removed by hand without special tools. The FLO tool had safety features to prevent premature release or incorrect placement. The FLO tool did not require fluid communication with the control system, as its purpose was solely flapper lock out.
The FLO tool did have some disadvantages. One was that the band could become dislodged under high gas flow rates. The tool was complicated and expensive to manufacture. The expanding ring presented design challenges and required stocking a large variety to accommodate different conditions. The running method required two wireline trips with jar-down/jar-up activation.
U.S. Pat. No. 4,574,889 assigned to Camco, now Schlumberger, required latching in the SSSV and stroking the flow tube down to the valve open position. The flow tube would then be outwardly indented in the valve open position so that the indentations would engage a downwardly oriented shoulder to prevent the flow tube from moving back to the valve closed position. This design had some of the advantages of the Baker Hughes FLO design and could accomplish the locking open with a single wireline trip. The disadvantages were that the flow tube was permanently damaged and that the flow tube had to be forced against a closure spring force before being dimpled to hold that position. This made disassembly of the SSSV with the flow tube under spring pressure a potentially dangerous proposition when the valve was later brought to the surface.
U.S. Pat. No. 5,564,675 assigned to Camco, now Schlumberger, also involved forcibly pushing the flow tube against the spring to get the flapper into the open position. In fact, the flow tube was over-stroked to push the actuator piston out of its bore in the pressurized control system, at which point the piston would have a portion splay out preventing its re-entry into the bore, thereby holding the flow tube in the flapper open position. This design had the safety issues of disassembly at the surface where the flow tube was under a considerable spring force. Additionally, fluid communication into the control system was not an option when locking open using this tool.
U.S. Pat. No. 6,059,041 assigned to Halliburton uses a tool that forces the flow tube down to get the flapper in the open position. It then releases a band above the flow tube that lodges on a downwardly oriented shoulder to hold the flapper open. This system has the risk of a flow tube under a spring force causing injury when later disassembled at the surface. This tool is fluid activated and must overcome the spring force to get the flow tube to the flapper open position. Finally, the tool is fluid pressure actuated, which will require a long fluid column to eventually communicate with the formation, a particular disadvantage in gas wells.
Also of interest in the area of lock open devices for SSSVs are U.S. Pat. Nos. 4,624,315; 4,967,845 and 6,125,930 (featuring collet fingers on the end of the flow tube that engage a groove in the SSSV body).
The present invention addresses these shortcomings by providing a technique to use a tool to get the flapper open without shifting the flow tube. In the preferred embodiment the flapper base is shifted with the flapper in the open position to trap the flapper in the open position. The closure spring that normally biases the flow tube into the flapper closed position is employed after the flapper base is liberated to bias the held-open flapper into its retaining grove. The lock open feature can be combined with stroking an oriented penetrating tool into the control system conduit for access to operate a subsequently installed valve to replace the locked open SSSV. The penetration step is not required to obtain the lock open state. Optionally the flapper base can be retained in its normal operating position by a shearable thread to allow taking advantage of a metal-to-metal sealing feature of the thread. These and other advantages of the present invention will become more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the claims appended below.
SUMMARY OF THE INVENTION
A lock open device for a flapper is disclosed. The tool engages in the sub-surface safety valve (SSSV) body and rotates the flapper to the open position, without shifting the flow tube. The flapper base is preferably held by a shearable thread and has a groove for engagement by the tool. The tool jars down on the flapper base to shear the thread and force the held open flapper into a retaining groove. Optionally, a penetrating tool can be connected so that, in a single trip, the flapper can be locked open and the pressurized control system can be accessed. Shearing the thread allows the flow tube spring to bias the held open flapper into its retaining groove.
DETAILED DESCRIPTION OF THE DRAWINGS
FIGS. 1 a - 1 e are a section view of the SSSV in the closed position;
FIGS. 2 a - 2 e are a section view of the SSSV with the lock open tool latched;
FIGS. 3 a - 3 e show the collets freed at the base of the tool to push the flapper into the fully open position;
FIGS. 4 a - 4 e are a section view showing the flapper base engaged by the tool just before the threads shear;
FIGS. 5 a - 5 e are a section view with the flapper base sheared and the flow tube spring acting on the flapper base to retain the flapper in the lock open recess;
FIGS. 6 a - 6 e show the SSSV in section with the lock open tool removed;
FIGS. 7 a - 7 c shows the addition of the penetrating tool above the lock open tool;
FIG. 8 is the penetrating tool after rotation;
FIG. 9 is the penetrating tool after penetration;
FIG. 10 shows the flapper in the normal operating closed position with an enlarged hinge diameter; and
FIG. 11 is the view of FIG. 10 with the enlarged hinge diameter forced down into interference with an adjacent reduced bore diameter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The sub-surface safety valve is illustrated in the closed position for the flapper 12 , in FIG. 1 . Spring 16 bearing on shoulder 18 biases the flow tube 14 upwardly. Flapper 12 is secured to flapper base 20 at pivot 22 . Spring 24 biases flapper 12 to the closed position shown in FIG. 1 d . Flapper base 20 is secured by sleeve 26 to body 28 . That connection is preferably by a thread 30 . Thread 30 is designed to release under a predetermined force applied to flapper base 20 . Other retainers that selectively release such as shear pins or collets can be used instead of thread 30 as contemplated in alternative forms of the present invention. A piston 32 sees pressure from a control line extending from the surface (not shown) and connected to port 34 . Piston 32 engages groove 36 to push the flow tube 14 down against the force of spring 16 . Grooves 38 and 40 are for locating the lock open tool T as shown in FIG. 2 b . FIG. 1 d shows an enlargement of the area around thread 30 .
FIGS. 2 a - 2 e illustrate the initial insertion of the tool T. Tool T has a mandrel 42 made up of a top sub 44 connected to segment 46 at thread 48 . Segment 50 is connected to segment 46 at thread 52 with the connection held locked by screws 54 . Segment 56 is held to segment 50 at thread 58 with the connection locked by screws 60 . Segment 56 further comprises a tapered shoulder 62 . Collet retainer 64 is secured by thread 66 to segment 56 by screws 67 . Collet retainer 64 comprises an extension segment 68 that defines an annular groove 70 in which the lower ends 71 of the collets 82 are disposed. The outer assembly 72 fits over the mandrel 42 and comprises a top sub 74 retained to segment 46 of mandrel 42 by a shear pin or pins 76 . Segment 75 is retained to top sub 74 at thread 77 . Projections 79 and 81 latch respectively into grooves 38 and 40 of body 28 due to the flexible nature of segment 75 . Segment 78 is retained to segment 75 by a shear pin or pins 80 . Collets 82 are secured to segment 78 by shear pin or pins 84 . Collets 82 have an internal shoulder 86 for jarring down and an external shoulder 88 to engage groove 90 on flapper seat 20 . Flapper seat 20 can be made of several interconnected parts. Spring 16 bears on flapper seat 20 for reasons to be explained below. Insertion of tool T results in a partial rotation of the flapper 12 toward the fully open position. The flapper is in the fully open position when in alignment with groove 92 in body 28 as shown in FIGS. 3 d - 3 e.
The significant components now having been described, the operation of the tool will be reviewed in detail. The tool T is lowered into the valve 10 until projections 79 and 81 spring into grooves 38 and 40 for latching contact. This position is shown in FIGS. 2 a - 2 b . The collets 82 still have their lower ends 71 held by collet retainer 64 , but the insertion itself has resulted in partial rotation of flapper 12 towards its fully open position. Actuating the mandrel 42 downwardly with a wireline operated jarring tool (not shown) connected to top sub 44 forces down the mandrel 42 . Initially, shear pin or pins 76 break as the mandrel moves with respect to the outer assembly 72 , which is supported to body 28 at grooves 38 and 40 . Downward movement of the mandrel 42 moves collet retainer 64 away from lower ends 71 of collets 82 , allowing them to spring radially outwardly so that shoulder 88 engages groove 90 in flapper seat 20 . This is shown in FIG. 3 d . The mandrel 42 continues moving down until shoulder 51 on segment 50 engages shoulder 53 on segment 78 of the outer assembly 72 . At this time shear pin or pins 80 will break after the application of a predetermined force. When shear pin or pins 80 break, segment 78 of the outer assembly 72 is driven down until lower end 83 engages shoulder 86 on collets 82 . By this time the collets 82 have pushed the flapper 12 into the fully open position so that it is in alignment with groove 92 in body 28 . Movement of the lower end 83 of segment 78 breaks shear pin or pins 84 , as shown in FIG. 4 d . When a predetermined force is applied to shoulder 86 from lower end 83 the thread 30 holding flapper base 20 to sleeve 26 shears or otherwise fails and the flapper base 20 is driven down, now also with the help of spring 16 until the flapper 12 has entered groove 92 . Spring 16 retains flapper 12 in groove 92 . Collets 82 insure the alignment of flapper 12 with groove 92 as the flapper is driven down from the force of the jarring tool on the wireline (not shown) acting on mandrel 42 and from spring 16 . The tool T can now be removed by an upward force on the wireline (not shown) and the flapped remains locked in groove 92 under the force of spring 16 , as shown in FIGS. 6 a - 6 e . The downward movement of flapper base 20 can be purely translation, as described for the preferred embodiment, or rotation or a combination of both movements to get the flapper 12 into groove 92 .
Referring to FIGS. 7 a - 7 c , the penetration tool P can be added above the lock open tool T. The lock open tool terminates near shoulder 51 at thread 95 . The assembly of the tool T and the tool P are initially suspended in grooves 38 and 40 as collet 94 springs outwardly. Collet 94 comprises an internal shoulder 96 and a lower end 98 , which covers window 100 . Mandrel 102 is connected to the jarring tool (not shown). Shear pin 104 secures sleeve 106 to mandrel 102 so that the entire assembly is initially supported by collet 94 . Outer housing 108 has an exterior shoulder 110 near its upper end 112 . Window 100 is in outer housing 108 . At its lower end 114 , outer housing is attached by shear pin 80 to segment 78 , as previously described. Guide pin 114 is biased by spring 116 but lower end 98 of collet 94 holds in pin 114 until shear pin 104 is broken. When mandrel 102 is advanced after shear pin 104 is broken, pin 114 is pushed out by spring 116 to contact spiral ramp 118 that is part of the SSSV. Such contact coupled with advancement of the mandrel 102 creates rotation as pin 114 advances along spiral ramp 118 and toward longitudinal groove 120 . Eventually, all rotational movement is complete as pin 114 in groove 120 and shoulder 110 hits shoulder 96 . This is the position in FIG. 8 . Now shear pin 122 can break as mandrel 102 and wedge surface 124 push penetrator assembly 126 through window 100 and into control system 128 above piston 32 (see FIG. 9 ).
While the rotation to get alignment for penetration is going on, the tool T is opening the flapper 12 and latching into groove 90 as shown in FIGS. 2 e - 4 e . When the penetration occurs the shear out of thread 30 occurs and the flapper 12 is displaced into groove 92 . Thus both steps can occur in a single trip or either step can be done individually without the other.
FIGS. 10 and 11 show a variation of holding the flapper 12 in the open position. It can be held open with a combination of groove 92 , as previously described as well as an enlarged diameter hinge 130 that is forced down into a reduced diameter segment 132 for an interference fit. FIG. 11 shows that groove 92 can be eliminated and the interference fit between hinge 130 and reduced diameter segment 132 can be the sole mechanism to insure the flapper 12 stays open after the thread 30 is sheared out.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention. | A lock open device for a flapper is disclosed. The tool engages in the sub-surface safety valve (SSSV) body and rotates the flapper to the open position, without shifting the flow tube. The flapper base is preferably held by a shearable thread and has a groove for engagement by the tool. The tool jars down on the flapper base to shear the thread and force the held open flapper into a retaining groove. Optionally, a penetrating tool can be connected so that, in a single trip, the flapper can be locked open and the pressurized control system can be accessed. Shearing the thread allows the flow tube spring to bias the held open flapper into its retaining groove. | 4 |
[0001] This application claims the benefit of the Patent Korean Application No. 10-2006-0007834, filed on Jan. 15, 2006, which is hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to laundry dryers, more particularly, to a laundry dryer which enables selective mounting/dismounting of a control panel on an upper or lower side of a front of the laundry dryer, as well as easy dismounting of a heater assembly out of the laundry dryer.
[0004] 2. Discussion of the Related Art
[0005] In general, laundry finished with washing is moved to and dried at a drying stand, naturally. However, in a case the weather is irregular, or in a rainy season, the natural drying of the laundry is delayed, such that the busy modern people experience much inconvenience.
[0006] Consequently, an appliance for drying the laundry regardless of the weather is required, to develop the laundry dryer.
[0007] Recently, it is a trend that demands on the laundry increases rapidly for the busy modern people.
[0008] The laundry dryer generates hot air with heating means and blows the hot air toward a drum, to vaporize moisture from a drying object.
[0009] In the laundry dryer, there are a condensing type laundry dryer, and an exhaust type laundry dryer depending on a system for processing humid air.
[0010] A related art exhaust type laundry dryer will be described with reference to FIG. 1 attached hereto.
[0011] Referring to FIG. 1 , the laundry dryer is provided with a body case 10 , a drum 20 , a fan 30 , and a heater assembly 40 .
[0012] The body case 10 forms an exterior of the laundry dryer. The body case 10 has a laundry opening 11 in a front for introducing laundry into the drum 20 .
[0013] Mounted on an upper side of the body case 10 , there is a control unit 12 for controlling operation of the laundry dryer, having an inside with a circuit board 12 a connected to various electric outfits mounted thereon, and an outside mounted with operation buttons 12 b and a display window (not shown) connected to the circuit board 12 a mounted thereon.
[0014] The drum 20 is mounted in the body case 10 , with an opening aligned with the laundry opening 11 . There is a door D at one side of the laundry opening 11 for selective opening/closing of the laundry opening 11 .
[0015] Mounted under the drum 20 , there is the heater assembly 40 , and there is the fan 30 on a position different from the heater assembly 40 for blowing the hot air to an outside of the laundry dryer through an inside of the drum 20 .
[0016] However, the related art laundry dryer has the following problems.
[0017] First, in a case the circuit board 12 a that controls the laundry dryer is out of order, or the various operation buttons 12 b on the control unit 12 are broken, it has been very inconvenient in repairing or replacing the circuit board 12 a or the operation buttons 12 b.
[0018] That is, since the control unit 12 is fixedly secured to the body case 10 , the servicemen experience substantial inconvenience in repairing.
[0019] Second, at the time the heater assembly 40 under the drum 20 is out of order, in order to repair or replace the heater assembly 40 , there is difficulty of removing various components mounted above the heater assembly 40 .
SUMMARY OF THE INVENTION
[0020] Accordingly, the present invention is directed to a laundry dryer.
[0021] An object of the present invention is to provide a laundry dryer which enables selective mounting/dismounting of a control panel on an upper or lower side of a front of the laundry dryer, as well as easy dismounting of a heater assembly out of the laundry dryer without disassembly of an entire body case.
[0022] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0023] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a laundry dryer includes a body case forming an exterior of the laundry dryer, a drum in the body case for holding a drying object, a heater assembly in the body case for heating air to supply hot air to the drum, a panel frame on a front of the body case, having an opening in communication with a space having the heater assembly mounted therein, and a control panel mounted to the panel frame selectively, having buttons for making various operation.
[0024] Preferably, the panel frame includes an upper panel frame on an upper side of the front of the body case, and a lower panel frame on a lower side of the front of the body case.
[0025] Preferably, the heater assembly is mounted in the body case at a lower portion thereof.
[0026] Preferably, the lower panel frame has an opening.
[0027] In this instance, preferably, the opening and the heater assembly are arranged on a straight line.
[0028] Preferably, the opening has a size enough to take out the heater assembly.
[0029] Preferably, the control panel can be mounted to the upper panel frame or the lower panel frame, selectively.
[0030] Preferably, the laundry dryer further includes a cover panel for covering the other panel frame if the control panel is mounted to one of the upper panel frame and the lower panel frame.
[0031] Thus, the laundry dryer of the present invention has the following advantages.
[0032] As described, since the control panel can be detachable from the body case, replacement or repair of the operation buttons and the display window on the control panel can be very convenient.
[0033] Since the control panel can be mounted to the upper side or lower side of the front of the laundry dryer selectively, the user's handling of the operation buttons on the control panel is convenient even if two or more than two laundry dryers are arranged in any type.
[0034] The opening in the panel frame permits easy taking out, and repair of the heater assembly.
[0035] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
[0037] FIG. 1 is a longitudinal section illustrating a related art laundry dryer.
[0038] FIG. 2 is an exploded perspective view illustrating a laundry dryer in accordance with a first preferred embodiment of the present invention.
[0039] FIG. 3 is a longitudinal section illustrating the laundry dryer in FIG. 2 in an assembled state.
[0040] FIG. 4 is a front view illustrating the laundry dryers of the present invention arranged in an up/down direction.
[0041] FIG. 5 is a front view illustrating the laundry dryers of the present invention arranged side by side.
DETAILED DESCRIPTION OF THE INVENTION
[0042] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0043] A laundry dryer in accordance with a first preferred embodiment of the present invention will be described with reference to FIGS. 2 and 3 .
[0044] Referring to FIG. 2 , the laundry dryer includes a body case 100 , a heater assembly 200 , a panel frame, and a control panel 400 .
[0045] The body case 100 , an exterior of the laundry dryer, includes a top plate 110 which is a top portion of the laundry dryer, a cabinet 120 which is opposite sides thereof, a back cover 130 which is a rear thereof, and a cover cabinet 140 which forms a portion of a front thereof.
[0046] The cover cabinet 140 has a laundry opening 150 for putting in/taking out laundry, and there is a door D at one side of the cover cabinet 140 having the laundry opening 150 formed therein for selective opening/closing of the laundry opening 150 .
[0047] It is preferable that the back cover 130 has a plurality of air inlets 131 for smooth drawing of external air.
[0048] The heater assembly 200 heats the air introduced into the body case 100 , and preferably is mounted under the drum Dr.
[0049] This is because a lower space of the body case 100 is the most suitable place for mounting the heater assembly 200 therein in view of arrangement of various components in the body case 100 .
[0050] Referring to FIG. 3 , the heater assembly 200 and the drum Dr are connected with an inlet duct Id to each other.
[0051] The inlet duct Id is a hot air passage from the heater assembly 200 to the drum Dr.
[0052] There is an outlet duct Od connected to the other side of the drum Dr. The outlet duct Od is a passage for discharging air and steam that dried the laundry from the drum.
[0053] Mounted on an inside of the outlet duct Od, there is the fan F for generating suction force for drawing external air into the drum Dr, and discharging steam from the drum Dr to an outside of the laundry dryer.
[0054] The panel frame is mounted to an upper side and a lower side of the cover cabinet 140 for mounting the control panel 400 or the cover panel to be explained later, respectively.
[0055] The panel frame includes an upper panel frame 500 mounted to the upper side of the cover cabinet 140 , and a lower panel frame 300 mounted to the lower side of the cover cabinet 140 .
[0056] In the lower panel frame 300 , there is an opening 310 for taking the heater assembly 200 out of the body case 100 .
[0057] The opening 310 is in communication, and arranged on a straight with a space of the body case 100 wherein the heater assembly 200 is mounted.
[0058] The opening 310 has a size enough to take out the heater assembly 200 .
[0059] It is preferable that the opening 310 has a shape similar to an outline of the heater assembly 200 for taking out the heater assembly, easily.
[0060] In the meantime, it is preferable that the opening 310 is formed only in the lower panel frame 300 in a case the heater assembly 200 is mounted in a lower portion of the body case 100 like the first embodiment.
[0061] The control panel 400 enables the user to control operation of the laundry dryer, and has various operation buttons required for the control mounted thereon.
[0062] For this, there is a circuit board 410 on an inside of the control panel 400 having various circuitry components mounted thereon.
[0063] The control panel 400 is designed to be mounted on the upper panel frame 500 or the lower panel frame 300 , selectively.
[0064] Referring to the first embodiment of the present invention, the control panel 400 is mounted on the lower panel frame 300 of the body case 100 .
[0065] In the meantime, the circuit board 410 has a cable (not shown) exposed to the lower panel frame 300 for transmission of operation of the laundry dryer to the various components.
[0066] That is, the cable has one end connected to a connector, and the other end connected to the circuit board 410 , electrically.
[0067] Mounted on an outside surface of the control panel 400 , there are the various operation buttons 420 and the display window 430 connected to the circuit board 410 electrically.
[0068] The various operation buttons 420 controls operation of the laundry dryer and the display window 430 displays operation progress of the laundry dryer.
[0069] The control panel 400 is designed to be mounted on the lower panel frame 300 of the laundry dryer selectively.
[0070] In the meantime, the upper panel frame has the cover panel mounted there on for covering the upper panel frame from an outside of the laundry dryer.
[0071] The cover panel is mounted to the other panel frame if the control panel is mounted to one of the upper panel frame and the lower panel frame.
[0072] Owing to this, the laundry dryer causes no problem in view of exterior thereof even if the control panel is mounted to either position.
[0073] It is preferable that the cover panel 600 has a shape identical to an outer shape of the control panel 400 so that the cover panel 600 can form a portion of a whole exterior of the laundry dryer.
[0074] A mounting structure of the cover panel 600 to the panel frame 300 or 500 is identical to a mounting structure of the control panel 400 to the panel frame 300 or 500 .
[0075] A mounting/dismounting state of the control panel to the lower panel frame of the laundry dryer, and a taking out state of the heater assembly will be described.
[0076] The upper panel frame 500 and the lower panel frame 300 are mounted to the upper side and the lower side of the cover cabinet of the laundry dryer, respectively.
[0077] The opening 310 in the lower panel frame 300 is on a straight line with a position of the heater assembly 200 in the body case 100 .
[0078] Then, since the cable (not shown) connected to the various components in the body case is exposed from an outside of the lower panel frame 300 , the cable connected to the circuit board 410 of the control panel 400 is electrically connected to the cable connected to the components in the body case 100 .
[0079] Then, as the control panel 400 is mounted to the lower panel frame 300 , a process for mounting the control panel 300 to the laundry dryer is finished.
[0080] Along with this, the cover panel 600 is mounted to the upper panel frame 500 by a method the same with a method of mounting the control panel 400 to the lower panel frame 300 .
[0081] In the meantime, a process for taking out the heater assembly out of the body case will be described.
[0082] At first, a process of mounting the control panel 400 to the lower panel frame 300 is progressed reversely, to dismount the control panel 400 from the lower panel frame 300 .
[0083] Then, a series of work for detaching the heater assembly 200 mounted on an inside of the body case 100 is progressed through the opening 310 of the lower panel frame 300 .
[0084] Upon finish of the work, the worker can take the heater assembly 200 out of the body case through the opening 310 , easily.
[0085] A work for mounting the heater assembly 200 in the body case 100 is progressed in a process reverse to above process, of which detailed description will be omitted.
[0086] In the meantime, it is described that the control panel can be mounted/dismounted to the upper side or the lower side of the cover cabinet 140 , selectively.
[0087] This is for easy operation of the operation buttons on each of the control panels even if two or more than two laundry dryers are arranged in any type.
[0088] States of the control panels arranged different from one another depending on states of two or more than two dryers arranged different from one another will be described with reference to FIGS. 4 and 5 .
[0089] FIG. 4 illustrates a state in which another dryer 2 (hereafter called as ‘a second dryer’) is stacked on a dryer 1 (hereafter called as ‘a first dryer’) supported on a floor.
[0090] In this case, it is preferable that the control panel 400 of the second dryer 2 is mounted to the lower panel frame 300 of the second dryer 2 .
[0091] This is for enabling the user to use the operation buttons 420 and the display window 430 of the control panel 400 conveniently, taking a general height of the user into account.
[0092] In this instance, the cover panel 600 is mounted to the upper panel frame 20 a of the second dryer 2 .
[0093] On the other hand, FIG. 5 illustrates a state the second dryer 2 is arranged on a side (a right side) of the first dryer 1 .
[0094] In this case, it is preferable that the control panel 400 of the second dryer 2 is mounted to the upper panel frame 500 of the second dryer 2 .
[0095] Referring to FIG. 4 , it is for preventing the user from bending the body or squatting down for operation of the operation buttons 420 on the control panel 400 in a case the control panel 400 of the second dryer 2 is mounted to the lower panel frame 300 of the second dryer 2 .
[0096] By enabling to vary a position of the control panel 400 according to an arrangement of the laundry dryer, the user can handle the operation buttons on the control panel, conveniently.
[0097] eventually, at the time the operation buttons 420 or the circuit board 410 of the control panel 400 is replaced or repaired, not only the control panel 400 can be dismounted from the laundry dryer and perform an appropriate work, but also the heater assembly 200 can be taken out of through the opening 310 easily and perform an appropriate work when the heater assembly 200 is out of order.
[0098] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | Laundry dryer including a body case forming an exterior of the laundry dryer, a drum in the body case for holding a drying object, a heater assembly in the body case for heating air to supply hot air to the drum, a panel frame on a front of the body case, having an opening in communication with a space having the heater assembly mounted therein, and a control panel mounted to the panel frame selectively, having buttons for making various operation, thereby permitting easy handling of the operation buttons on the control panel even if two or more than two dryers are arranged in any type, and improving workability of replacement or repair of the heater assembly. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention demonstrates the method of fabricating porous silicon metal-semiconductor-metal planar photodetector.
2. Description of the Prior Art
Photodetector is a device that can convert light signal into electrical signal. It is widely used in various areas like communication, computer, control, and medical applications. Since silicon cannot emit light efficiently, optoelectronics is developed in the area of compound semiconductor. So far high illumination light emitting diode has been developed from porous silicon, therefore if there is a corresponding planar photodetector, then silicon integrated optoelectronic circuit can be developed. Metal-semiconductor-metal planar photodetector (M-S-M) is of great potential to be applied in optoelectronics integrated circuit since (1) it's structure is planar, (2) no minority carrier storage and the distance between electrodes is short so that the response is fast, (3) simple to fabricate, low cost, (4) high electro-optics conversion efficiency, and also high stability photodetector is demanded by the market widely.
There are four advantages to apply porous silicon in photodetector: (1) since it is direct bandgap, so the elector-optics conversion efficiency is high, (2) porous surface can increase the absorption rate of light (3) it has high gain due to avalanche effect, (4) simple to fabricate, low cost, so porous silicon is a good photodetecting material. The present invention fabricates a high gain and low leakage current porous silicon metal-semiconductor-metal planar photodetector.
Silicon is the most matured semiconductor material developed so far. well The integrated circuit technology of silicon is well developed. Optoelectronic integrated circuit is the future integrated circuit which has faster speed, since it transmits signal with the speed of light. Photodetector is the necessary device of optoelectronic integrated circuit in the respect of function and structure. Metal-semiconductor-metal photodetector is planar photodetector, specially suitable to be used in optoelectronic integrated circuit. Furthermore, since it has no minority carrier storage and the distance between electrodes is short so the response is fast.
Porous silicon differs from bulk silicon, according to the report of L. T. Canham in Appl. Phys. Lett ., Vol. 57, pp.1046 (1990), after the silicon surface is etched by the current in electrolytic solution and becomes porous, the energy band is folded and its indirect energy gap becomes direct bandgap, so that the electro-optics conversion efficiency is increased, therefore the quantum coefficient of photon is increased. At the same time since the surface of porous silicon is porous which can eliminate the secondary reflection of light, so the absorption rate of light is increased, we can obtain better photocurrent and photosensitivity without antireflection coating.
Additionally, the wire size of the porous silicon is very narrow, and it is in complete depletion, so the avalanche effect in the local region will occur due to bias and amplify the optical signal, and thereby the photodetector will have high gain.
From the above, there are five advantages to apply porous silicon in photodetector: (1) since it is direct bandgap, so the electro-optics conversion efficiency is high, (2) porous surface can increase the absorption rate of light (3) it has high gain due to avalanche effect, (4) directly formed on silicon wafer so that it is totally matched with silicon integrated circuit. (5) its fabrication process and structure are simple and the cost is low, so porous silicon is a good photodetector material.
But as-grown porous silicon photodetector has several disadvantages: (1) optical and electrical characteristics are not stable, (2) photocurrent and photosensitivity is not high enough, (3) dark current is not low enough, which limits the application of photodetector.
The following depicts the problems hereby resolved by the present invention.
So far the development of metal-semiconductor-metal porous silicon photodetector still has the following problems: (1) photocurrent and photosensitivity is not high enough, (2) dark current is not low enough, which limits the application of planar metal-semiconductor-metal photodetector in optoelectronic integrated circuit.
SUMMARY OF THE INVENTION
The present invention applies the method of rapid thermal oxidation (RTO) and rapid thermal annealing (RTA) to fabricate high gain and low leakage current porous silicon metal-semiconductor-metal planar photodetector. The photocurrent and photosensitivity of the present invention is raised high, and the dark current of the present invention is reduced, which makes the application of planar metal-semiconductor-metal photodetector in optoelectronic integrated circuit to be more widespread.
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 shown the structure of the aluminum electrode of planar metal-semiconductor-metal photodetector on the front side.
1. Bonding pad
2. Finger type light absorption area
FIG. 2 shown the photocurrent response and the I-V characteristics of dark current after the processing of rapid thermal oxidation (RTO) for 60 sec at 850° C. of porous silicon metal-semiconductor-metal planar photodetector
FIG. 2 ( a ) shown the I-V characteristics of dark current.
FIG. 2 ( b ) shown the I-V characteristics of photocurrent under the illumination of 0.85 mW 675 nm laser diode.
FIG. 2 ( c ) shown the I-V characteristics of photocurrent under the illumination of 24 mW/cm 2 tungsten lamp.
FIG. 3 shown the photocurrent as a function of the oxidation time of rapid thermal oxidation (RTO) of porous silicon metal-semiconductor-metal planar photodetector
(i) The variation of photocurrent with respect to the oxidation time of rapid thermal oxidation (RTO) under the illumination of 24 mW/cm 2 tungsten lamp at −10V
(ii) The variation of photocurrent with respect to the oxidation time of rapid thermal oxidation (RTO) under the illumination of 0.85 mW 675 nm laser diode at −10V.
FIG. 4 shown the I-V characteristics of dark current after being processed by rapid thermal oxidation (RTO) for 90 sec at 850° C. (without being processed by rapid thermal annealing).
FIG. 5 shown the I-V characteristics of dark current of the porous silicon metal-semiconductor-metal planar photodetector after being processed by rapid thermal oxidation (RTO) at 850° C. for 90 sec, and then processed by rapid thermal annealing (RTA) at 850° C. for 60 sec.
FIG. 6 shown the I-V characteristics of photocurrent of the porous silicon metal-semiconductor-metal planar photodetector after being processed by rapid thermal oxidation (RTO) for 90 sec at 850° C. (without being processed by rapid thermal annealing).
(i) I-V characteristics of dark current.
(ii) I-V characteristics of photocurrent under the illumination of 0.85 mW 675 nm laser diode.
(iii) I-V characteristics of photocurrent under the illumination of 24 mW/cm 2 tungsten lamp.
FIG. 7 shown the I-V characteristics of photocurrent of the porous silicon metal-semiconductor-metal planar photodetector after being processed by rapid thermal oxidation (RTO) at 850° C. for 90 sec, and then processed by rapid thermal oxidation (RTO) at 850° C. for 60 sec.
(i) I-V characteristics of dark current.
(ii) I-V characteristics of photocurrent under the illumination of 0.85 mW 675 nm laser diode.
(iii) I-V characteristics of photocurrent under the illumination of 24 mW/cm 2 tungsten lamp.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The goal of the present invention is to fabricate planar porous silicon metal-semiconductor-metal photodetector, and applies the method of rapid thermal oxidation (RTO) and rapid thermal annealing (RTA) to improve the photocurrent and photosensitivity of the porous silicon metal-semiconductor-metal photodetector, and also to improve the dark current of the present invention so that the application of planar metal-semiconductor-metal photodetector in optoelectronic integrated circuit is even more widespread.
The goal of the present invention is to fabricate the structure of planar porous silicon metal-semiconductor-metal photodetector. The structure of the present invention from top to bottom is: aluminum finger type electrode/porous silicon/silicon substrate/aluminum ohmic contact.
Said the method of fabricating porous silicon metal-semiconductor-metal planar photodetector of the present invention, which includes the following steps:
(1) Plate one layer of conducting material on the back side of the silicon substrate;
(2) Anneal the silicon substrate which is plated with conducting material on the back side in inert gas for some time;
(3) Apply one layer of anti-corrosion coating on the conducting material on the back side of the silicon substrate;
(4) Soak the silicon substrate into the aqueous solution of HF with appropriate concentration, apply proper amount of current, and etch the silicon surface for a proper duration to form porous silicon;
(5) Remove the anti-corrosion coating on the back side of the silicon substrate;
(6) Oxidize the porous silicon in rapid thermal oxidation furnace for a proper duration at a proper temperature to increase carrier lifetime, improve the photocurrent and photosensisitivity of the porous silicon photodetector;
(7) Put the porous silicon substrate into rapid thermal annealing furnace, do rapid thermal annealing for a proper duration at a proper temperature to remove the defect, so that very good photocurrent response and very low dark current of the porous silicon photodetector can be obtained;
(8) Plate finger type electrode on porous silicon to obtain high quality planar porous silicon metal-semiconductor-metal photodetector.
Said the method of fabricating porous silicon metal-semiconductor-metal planar photodetector in the present invention, wherein said the conducting material is aluminum, wherein said the anti-corrosion coating is black wax, wherein said the structure of the finger type electrode is as shown in FIG. 1, wherein said the condition to form porous silicon is: current density 20 mA/cm 2 , HF concentration 5%, etching time 15 min, the temperature and duration of rapid thermal oxidation and rapid thermal annealing are in the range of 600° C.˜950° C. and 15˜180 sec.
The following is the technical details and the special feature of the present invention:
Said the process of fabricating porous silicon metal-semiconductor-metal photodetector in the present invention is: (1) Plate aluminum on the back surface of the silicon wafer after ultracleaning, anneal to form ohmic contact, then apply black wax for protection. (2) The condition to form porous silicon is: current density 20 mA/cm 2 , HF concentration 5%, etching time 15 min and then remove the black wax. (3) Plate aluminum electrode on the front surface of silicon wafer, the structure is as shown in FIG. 1 . (4) cut the sample into 5×5 cm 2 dies, then package with TO-5, then porous silicon metal-semiconductor-metal photodetector is formed.
According to the report of V. Petrova-Koch et al. in Appl. Phys. Lett ., Vol. 61, pp. 943 (1992), the surface of porous silicon is filled with imperfect native oxide and according to the report of J. Yan et al in Appl. Phys. Lett ., Vol. 64, pp. 1374 (1993), recombination centers will form on the unstable hydrogen-passivated surface to reduce the lifetime of carrier, increase the dark current, and then reduce the photocurrent and photosensitivity, make the porous silicon photodetector unstable. This can be improved by RTO (rapid thermal oxidation) which can replace the imperfect native oxide with stable oxide and remove the unstable hydrogen-passivated surface, i.e. remove the recombination center, increase the carrier lifetime, and reduce the dark current, thus improve the photocurrent and photosensitivity of the porous silicon photodetector. Additionally, a structure of non-stoichiometric silicon oxide will form on the porous silicon surface due to the rapid oxidation and will form tunneling centers, which will increase the dark current of the photodetector at the same time, this can be improved by RTA (rapid thermal annealing) to remove the structure of non-stoichiometric silicon oxide, and improve the dark current.
The condition to form porous silicon is: current density 20 mA/cm 2 , HF concnentration 5%, etching time 15 min, and then processed by rapid thermal annealing at 850° C. for 60 sec. The structure of the porous silicon photodetector is shown in FIG. 1 . FIG. 2 is the photocurrent response and the I-V characteristics of dark current. FIG. 2 ( a ) is the I-V characteristics of dark current. At −10V the dark current is 38.2 μA, at +10V the dark current is 65.2 μA, FIG. 2 ( b ) is the I-V characteristics of photocurrent under the illumination of 0.85 mW 675 nm laser diode. At −10V the photocurrent is 485 μA, at +10V the photocurrent is 365 μA, FIG. 2 ( c ) is the I-V characteristics of photocurrent under the illumination of 24 mW/cm 2 tungsten lamp. At −10V the photocurrent is 3.81 mA, at +10V the photocurrent is 3.71 mA. The photocurrent will increase with voltage, and gradually reach saturation when the voltage is larger than 2V. The illustration in FIG. 2 is the detailed plot of dark current. From the figure, the fabrication process can actually make a planar porous silicon metal-semiconductor-metal photodetector.
The photocurrent with respect to the oxidation time of rapid thermal oxidation (RTO) of porous silicon metal-semiconductor-metal planar photodetector is shown in FIG. 3 . FIG. 3 (i) is the variation of photocurrent with respect to the oxidation time of rapid thermal oxidation (RTO) under the illumination of 24 mW tungsten lamp at −10V FIG. 3 (ii) is the variation of photocurrent with respect to the oxidation time of rapid thermal oxidation (RTO) under the illumination of 0.85 mW 675 nm laser diode at −10V. The photocurrent will increase with the oxidation time of RTO when the oxidation time is less than 150 sec. The maximum photocurrent is 15.9 mA in FIG. 3 (i), 1.83 mA in FIG. 3 (ii). From the figure, the RTO process can actually improve the photocurrent of the photodetector. For the case of 120 sec, the photosensitivity under the illumination of 0.85 mW 675 nm laser diode is 2.15 A/W after conversion. The corresponding quantum efficiency is 400%, this comes from the avalanche effect inside the porous silicon, and the latter is generated by the voltage drop in porous silicon which is intrinsic and as narrow as silicon wire. When the oxidation time is lager than 150 sec, the thickness of oxidation layer is so thick that the series resistance is too large, so the photocurrent will decrease with the RTO time.
Dark current is a very important characteristics of photodetector. FIG. 4 is the I-V characteristics of dark current after being processed by rapid thermal oxidation (RTO) at 850° C. for 90 sec (without being processed by rapid thermal annealing) of the planar porous silicon metal-semiconductor-metal photodetector. At −10V the dark current is 18.4 μA, the corresponding photocurrent is shown in FIG. 6, the photocurrent is 0.4 mA at −10V under the illumination of laser diode. At +10V the photocurrent is 0.5 mA as shown in FIG. 6 (ii). Under the illumination of 24 mW/cm 2 tungsten lamp, at −10V the photocurrent is 5.61 mA, at +10V the photocurrent is 4.31 mA as shown in FIG. 6 (iii). FIG. 5 is the I-V characteristics of dark current of the porous silicon metal-semiconductor-metal planar photodetector after being processed by rapid thermal oxidation (RTO) at 850° C. for 90 sec, and then processed by rapid thermal oxidation (RTO) at 850° C. for 60 sec. At −10V the dark current is decreased to 1.8 μA, the corresponding photocurrent is shown in FIG. 7, the photocurrent is 0.58 mA at −10V under the illumination of laser diode. At +10V the photocurrent is 0.73 mA as shown in FIG. 7 (ii). Under the illumination of 24 mW/cm 2 tungsten lamp, at −10V the photocurrent is 5.98 mA, at +10V the photocurrent is 8.52 mA as shown in FIG. 7 (iii). From the figure, RTO and RTA can actually improve the characteristics of the planar porous silicon metal-semiconductor-metal photodetector.
The planar porous silicon metal-semiconductor-metal planar photodetector fabricated by the present invention has 400% high gain. The photosensitivity of the present invention is much more improved than the other photodetector. The characteristics of the present invention is much improved, no matter in that of photocurrent or photosensitivity. | A high gain and low leakage current porous silicon metal-semiconductor-metal planar photodetector was fabricated through rapid thermal oxidation (RTO) and rapid thermal annealing (RTA). A high responsivity of 2.15 A/W can be obtained under a 0.85 mW 675 nm laser diode illumination. The gain is 400%. It shows high potential as a device applied in optoelectronics and optoelectronic integrated circuits. | 7 |
REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of a patent application entitled "WAFER HANDLING SYSTEM WITH BERNOULLI PICK-UP", assigned Ser. No. 048,630 and filed on May 11, 1987 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to wafer handling apparatus for use in a semiconductor processing system and, more particularly, to a pick up wand for lifting wafers without contact with the top or bottom surfaces of the wafer.
2. Description of the Prior Art
Many different types of semiconductor processing systems require the use of wafer handling systems or wafer transport mechanisms. The more widely used processing systems will be briefly described below. Chemical Vapor Deposition (CVD) is the formation of a stable compound on a heated substrate, such as a wafer, by the thermal reaction or deposition of various gaseous compounds. Epitaxial deposition is the deposition of a single crystal layer on a substrate (often of the same composition as the deposited layer), whereby the layer is an extension of the crystal structure of the substrate. Another example of CVD is generally classified as metallization wherein the processed silicon substrates have the metal connectors and the like deposited thereon. In an ion implantation process, selected ions of a desired dopant are accelerated using an electrical field and then scanned across the surface of a wafer to obtain a uniform predeposition. Batch processing systems involve the deposition of more than one substrate or wafer at a time.
In the batch processing, the wafers are carried in boats and the boats are usually loaded and unloaded as by use of tweezers, hand-held vacuum pick ups and the like. Loading robots may be used to transfer multiple wafers simultaneously. While batch processing systems have been used extensively, the modern trend is toward the use of single wafer transport systems in order to process ever larger semiconductor wafers having diameters of over 30 centimeters. These larger wafers can contain many more circuits and much more complex circuits than were heretofore possible. While single wafer systems have less throughput than batch processing systems, attempts are being made to speed up the single wafer processes, to develope higher yields, to avoid problems such as particle contamination and to increase uniformity and quality.
Most known single wafer transport mechanisms can be adapted for use in various types of semiconductor processing systems. Such transport mechanisms include the following. In a gravity feed transport system, the wafers are stacked in a supply receptacle, which receptacle is supported in an elevator at an angle to vertical; the wafer within the receptacle is free to slide out and along an inclined ramp to a vacuum mandrel. A second inclined ramp is provided to permit a processed wafer to slide down the second ramp into a receiving receptacle. The disadvantages of this type of mechanism include the lack of positive feed; the material placed onto the wafer can come off on contact with the ramps; contaminating particles may be generated by the ramps; and, it may be limited to a single size wafer. Another type of semi-automatic mechanism for transporting wafers utilizes air bearings. The wafers are maintained horizontal and are transported to and from the processing area upon a cushion of air. This type of mechanism has proven to be highly unreliable and includes many moving parts subject to breakage and maintenance down time. Foreign material may enter and damage the air bearings or reduce their effectiveness. Other transport mechanisms utilize air cushion guidance devices where the problem of cleanliness of the air and of the turbulence produced by the air cushion are quite significant. The settling of airborne particles onto the top surface of the wafers is difficult to avoid in air cushion systems. Further, lateral guard rails must be used, and contact between the edges of the wafer and the guard rails occurs frequently and may result in unacceptable contamination or damage to the wafers. Finally, only one size of wafer can be handled without significant modification and down time occurs when the wafer receptacles are being replaced manually.
Various mechanical transport systems have been used. One system uses a rotating carousel in combination of supply and receiving slides. Another system uses a belt drive transport to discharge the wafers from a supply cassette and at various other transfer points. As the cassettes are discharged successively from the bottom and loaded in reverse order, impurities often drop from the bottom of one wafer onto the top of the wafer beneath it. Additional problems arise at the transfer points because the transport motion of the wafers is terminated by stoppers which can result in previously deposited layers being spalled off or chipped off to further contaminate the wafer surfaces. Other wafer handling systems utilize a spatula or shovel type pick up to slide under the wafers or move under the wafers and come up through the cassette track spaces to pick up the wafers and carry them to the next location.
An arm type system utilizes a vacuum chuck positionable under a wafer for attachment to the underside of the wafer by producing a vacuum at the point of contact. The wafer is lifted out of the cassette and carried to a processing station or the like; this system cannot place a wafer on a flat continuous surface. Damage often results from the mechanical contact between the vacuum chuck and the wafer.
In summary, the trend of the prior art is toward single wafer processing systems. A key factor in automating such systems lies in improving the wafer transport mechanism. Furthermore, the critical problems presented by particle contamination become ever more important as wafers become larger and larger and as circuits become more and more complex. None of the known systems are sufficiently clean to enable their use in a completely automated processing system, nor do they avoid touching the top and/or bottom surfaces of the wafer.
SUMMARY OF THE INVENTION
A pick up wand assembly of the present invention utilizes the Bernoulli Principle for effecting a contactless pick up or lifting of the wafer. The wand assembly is mounted at the front of a robot arm, which arm includes passageways for receiving and distributing a gas to the pick up wand assembly. A plurality of gas outlets in a bottom plate of the pick up wand assembly produces an area of relatively low pressure between the top surface of the wafer and the bottom surface of the pick up wand assembly (with respect to the pressure existing beneath the wafer) for lifting the wafer without physical contact between the wafer and the pick up wand assembly. The plurality of gas outlets are oriented or slanted substantially radially outward from a central portion of a geometric pattern to produce an outward gas flow across the top surface of the wafer to be picked up. The gas flow: (1) establishes a zone of relatively low pressure between the bottom plate and the top surface of the wafer (relative to the pressure normally existing beneath the lower surface of the wafer) to enable a pick up from above the wafer without any physical contact between the wafer and the bottom plate; (2) provides a continuous outward sweeping action which sweeps the top surface of the wafer free of particles which might otherwise accumulate; (3) provides a uniform gap between the bottom plate and the top surface of the wafer; (4) exerts a soft gentle horizontal force on the wafer for moving it toward stops; and (5) avoids abrasion and damage to the wafer.
A primary object of the present invention is to provide a wafer transport mechanism employing a wafer pickup wand utilizing the Bernoulli Principle.
Another object of the present invention is to provide a wafer handling system utilizing a pick up wand for lifting a wafer without physical contact therebetween.
Yet another object of the present invention is to provide a wafer transport mechanism which greatly reduces particulate generation.
Still another object of this invention is to protect the top surface of a wafer from particulate contamination during pick up, transport, and drop off.
A further object of this invention is to provide a pattern of gas outlets on the bottom of a pick up wand for substantially, radially outwardly, directing the gas flow to provide for the creation of a low pressure area between the lower surface of the pick up wand and the upper surface of the wafer to enable the wafer to be picked up from above and without physical contact therewith while simultaneously providing an outward flow of air which flow continually sweeps the surface of the wafer to prevent contamination from particles.
A further object of the present invention is to provide a pick up wand which, by means of a particular pattern of outwardly oriented gas outlets, creates an outward gas flow at all points on the wafer perimeter to avoid drawing in particulate contaminants from the surroundings onto the wafer while creating a force to lift the wafer.
These and other objects of the invention will become apparent to those skilled in the art as the description thereof proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the wafer transport mechanism of the present invention as utilized in a semiconductor processing system;
FIG. 2 is a partially sectional top plan view of the wafer transport mechanism shown in FIG. 1;
FIGS. 3A-3P show a series of illustrations depicting the movements of the robot arms shown in FIG. 1;
FIG. 4 is an assembly drawing of the drive system;
FIG. 5 is an assembly drawing of the fluidic drive portion of the drive system shown in FIG. 4;
FIG. 6 is a sectional top view of the gear drive portion of the drive system shown in FIG. 4;
FIG. 7 is a top view of the robot arms shown in FIG. 1;
FIG. 8 is a side view of one of the robot arms shown in FIG. 7;
FIG. 9 is a perspective view of the pick up wand assembly shown in FIG. 1;
FIG. 10 is a sectional side view of the front end of the robot arms shown in FIG. 9;
FIG. 11 is an assembly drawing illustrating the front end of the robot arms the pick up wand assembly shown in FIG. 9;
FIG. 12 is a bottom view of the gas distribution plate shown in FIG. 9;
FIG. 13 is a sectional end view of the gas distribution plate shown in FIG. 12;
FIG. 14 is a sectional side view of the gas distribution plate shown in FIG. 12;
FIG. 15 is a top plan view of the plate shown in FIG. 9;
FIG. 16 is a sectional side view of one of the gas outlets shown in FIG. 15;
FIG. 17 is a sectional side view of a gas outlet shown in FIG. 15;
FIG. 18 is a partial sectional side view showing an apparatus for further reducing particle contamination; and
FIG. 19 is a partial sectional side view showing apparatus for particle elimination.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The wafer transport mechanism described herein may be used in an epitaxial deposition system but it can be used in other types of semiconductor processing systems.
Referring to FIGS. 1 and 2, substrate transport mechanism 21 includes a laminar flow envelope or enclosure 23 having a substantially hollow interior 25. Preferably, the enclosure is made of a non-contaminating material, such as anodized aluminum. The epitaxial deposition system in which substrate transport mechanism 21 is usable includes a reactor oven, reaction chamber, or reactor 27 having an access slot 83 to provide communications between hollow interior 25 with hollow interior 63 of the reactor. A gate valve (not shown) is provided for selectably opening or sealably closing access slot 83.
The epitaxial deposition system includes at least two purge boxes or stations 29, 31 for supplying wafers 81 to be processed and for storing the wafers after they are processed, respectively. Each of stations 29, 31 includes a hollow interior and one of access slots 35, 37, respectively, for communication with enclosure 23. Each of stations 29, 31 also includes a cassette 33 which sits on an indexing elevator. Each cassette includes a plurality of vertically stacked tracks for horizontally supporting the substrates or wafers on their outermost peripheral edges. Each wafer may be a six inch circular silicon wafer which is to have additional silicon deposited thereon. Each station 29, 31 also has an access door (not shown) on the side opposite the respective slot for human operator access to load and unload the cassettes.
The specific structures of stations 29, 31, cassettes, wafers, elevators, elevator indexing mechanisms, purging system and the like, are not critical to an understanding of the present invention and will not be described in any greater detail.
An arm mounting plate assembly 39 is disposed in a central recess in floor 45 of enclosure 23 and is used to operatively mount the rear end of a pair of robot arms 41 thereto. The combination of plate assembly 39 and individual shaft drives to the rear end of robot arms 41 enables the robot arms to be extended and retracted toward and away from the plate assembly and to be angularly repositioned from location to location, such as from station 29 to reactor 27, or the like. A pick up wand assembly 43 is operatively mounted to the front end of robot arms 41 for actually picking up or lifting wafers 81 for transport purposes.
Enclosure 23 includes a floor 45, a top surface 47, a first longitudinal side 49, a second longitudinal side 51, a first end side 53, a second end side 55, and a rear end side 57. Plate assembly 39, together with articulated robot arms 41 and the wand assembly 43, are all housed within the hollow interior of enclosure 23. Plate assembly 39 is mounted in a recess in floor 45 and driven by a drive assembly which is vacuum-sealed on the opposite side of the floor, as hereinafter described. Hollow interior 25 is adapted to provide a controlled clean atmosphere and the atmosphere is preferably one of hydrogen, nitrogen or argon.
FIG. 2 particularly illustrates robot arms 41 in various positions of extension and retraction from plate assembly 39. In a first position, the robot arms are designated by the reference numeral 65 and the wand assembly by reference numeral 67. In this position, wand assembly 67 is at its closest position to plate assembly 39 and this is referred to as the home position since it is only in this position that the plate assembly rotates to rotatably position the wand assembly from location to location. Reference numeral 69 illustrates the robot arms in a second position that the wand assembly 71 would occupy. A third position is indicated by reference numeral 73 which positions wand assembly 75 just inside of access slot 83 of reactor 27. Lastly, robot arm position 77 shows the pair of robot arms fully extended to position wand assembly 79 within hollow interior 63 of reactor 27 and over the susceptor for delivering wafer 81 thereto.
FIGS. 3A-3P illustrate the various positions of robot arms 41 with respect to wand assembly 43 and plate assembly 39. In each of these figures, a portion of enclosure 23 will be shown with at least one of stations 29, 31 or reactor 27. Directional arrows are provided to show either the direction of extension, the direction of retraction, or the direction of rotation during any one step, as represented by the individual figures.
In FIG. 3A, robot arms 41 are shown in their home position with wand assembly 43 facing station 29 and containing at least one wafer 81 to be picked up. In FIG. 3B, robot arms 41 have begun to extend away from plate assembly 39 and toward wafer 81. Directional arrow 85 shows the linear direction of movement during the wafer pick up operation. FIG. 3C shows robot arms 41 in their fully extended position with wand assembly 43 positioned through access slot 35 and into purge box 29 for picking up wafer 81 from a cassette on an elevator housed therein. FIG. 3D shows robot arms 41 in an intermediate position of retraction (as indicated by the directional arrow 87) after pick up of wafer 81, toward the home position shown in FIG. 3E. In FIG. 3E, robot arms 41 are again in the home position and ready for the rotational movement indicated by the rotational direction arrow 89 shown in FIG. 3F. In this position, the robot arms are in the home position and plate assembly 39 is rotated counterclockwise from station 29 toward the reactor 27.
In FIG. 3G, robot arms 41 are still in the home position but wand assembly 43 now faces access slot 83 of reactor 27. In FIG. 3H, the robot arms are again shown in an intermediate position while moving wafer 81 toward reactor 27, as indicated by directional arrow 91 showing the linear direction of movement from this position. FIG. 3I shows robot arms 41 in a fully-extended position such that wand assembly 43 can position or deposit wafer 81 onto the susceptor within reactor 27. FIG. 3J shows robot arms 41 at an intermediate position of retraction, as indicated by the directional arrow 93 and FIG. 3K shows the robot arms returned to their home position.
In FIG. 3L, plate assembly 39 again rotates counterclockwise, as indicated by directional arrow 92, to rotationally reposition wand assembly 43 and processed wafer 81 from reactor 27 and toward the access slot 37 of station 31. In FIG. 3M, robot arms 41 are in the home position with wand assembly 43 facing access slot 37 of station 31. In FIG. 3N, the robot arms are shown in an intermediate position of extension as they move toward access slot 37 of station 31, as indicated by directional arrow 94. In FIG. 30, the robot arms are fully extended into station 31 to deposit wafer 81 on the tracks of a cassette located therein. In FIG. 3P, the robot arms are shown in an intermediate retracted position as they once again return to the home position shown in FIG. 3M, as reflected by directional arrow 96.
FIG. 4 illustrates drive assembly 101 for extending and retracting robot arms 41 and rotating plate assembly 39. Rotatable plate 131 is a generally flat, circular plate which is operatively disposed within a cylindrical recess (not shown) located in floor 45 of enclosure 23. A pair of screw members (not shown) pass through apertures 140, 142 and secure plate 131 to the drive mechanisms therebelow while a pair of shafts 133 and 135 extend vertically above the plane of plate 131.
Shaft 133 is adapted to engage an aperture 144 in rear end connector 145 of robot arm segment 139 while the upper end of shaft 135 engages aperture 146 of end connector 147 at the rear end of second robot arm segment 141. Each of the lower robot arm segments is shown as being a generally elongated member having a conduit 143 for gas flow therethrough.
Drive assembly 101 includes a shaft drive motor 103 which is a conventional DC, digital, micro-stepping motor (such as Model No. M062-FC03E manufactured by Superior Electric Co. of Bristol, Conn.). Robot arm drive motor 105 is a digital DC micro-stepping motor (such as Model No. M092-FC08E manufactured by the Superior Electric Co. of Bristol, Conn.). Drive motor 103, which is used for the extension and retraction of robot arms 41, drives a flex shaft coupler, 124 (397 FIG. 5) which drives the ferrofluidic feedthru 409 which has a gear 167 and collar 171 attached to the gear box end (FIG. 6) of the feedthru shaft. Gear 167 then drives gear 165 (shaft assembly 135) which through shaft 135 drives gear 163 which then drives countershaft 133 by way of gear 161 in the opposite direction of shaft 135. Drive motor 105, which is used for the rotation of robot arms 41 and having a shaft 109 which has a drive pulley 111 mounted to it, drives belt 113 which drives pulley 115. Pulley 115 is attached to drive tube 122 which has motor 103, flange 123 mounted on the bottom and feedthru 409 and the gear box assembly (FIG. 6) mounted on the other (top) end. This drive tube is then mounted in the hollow shaft of feedthru 125. Pulley 115 has a collar 117 extending from the top surface; a channel 119 passes through the collar and the pulley. Drive shaft 121 of drive motor 103 (extension, retraction motor) extends vertically upwardly therefrom through internally-threaded collar 123 disposed on the upper surface of the housing of drive motor 103, a nut 128, channel 119, collar 117, through the interior of a vertically downwardly extending tubular stem 120 having an externally-threaded end portion 122 and into ferrofluidic drive housing 125 connecting to 409 (FIG. 5).
Ferrofluidic drive housing 125 will be more extensively described with joint reference to FIGS. 5 and 6. Gear housing 127 is coupled through a vacuum seal to interior 25 of enclosure 23. Robot arms 41, via the shaft extensions 133 and 135, are driven to extend and retract via the operation of the gears cooperating with ferrofluidic drive shaft 409, 121. The rotation of plate 131 of plate assembly 39 will no be described. The externally-threaded end 122 of stem 120 is inserted through channel 119, through nut 128, and threaded into collar 123. Nut 128 can be used as an adjustment or lock nut. Once end 122 is screwed into collar 123, pulley 115 is securely clamped to stem 120 and may be pinned by a pin extending through aperture 118 of collar 117 and a corresponding aperture (not shown) in stem 120. As motor 105 drives pulley 115, stem 120, which is fixedly secured to the bottom center of housing 125, rotates housing 127 supported by bearings in feedthru 125.
Ferrofluidic base plate 390 is shown in FIG. 5 a being attached to a metal bellows assembly 393 over which is mounted plate 132. Plate 132 includes a ring 395, an aperture 400 and a pair of elongated members 396. A motor-mounting plate 399 is disposed on elongated members 396 extending from ring 395. A hollow tubular stem or ferrofluidic drive tube assembly 401 includes stem 120 and an annular flange 405. Intermediate connector 397 passes inside of the threaded end of stem 120 and the base of tube assembly 40 is operatively disposed within the hollow central drive channel 388 of base plate 390. A ferrofluidic drive shaft 172 extends from the top surface of annular flange 405, through a ferrofluidic collar 409 to a pinion gear 167 and its shaft 171 disposed in housing 127. Shaft 172, tube assembly 401 and collar 409 comprise a ferrofluidic feedthrough mechanism 407 which brings about extension and retraction of robot arms 41.
The ferrofluidic drive apparatus described above is a commercially available conventional unit adapted herein to enable extension and retraction of the robot arms and rotational movement of plate assembly 39. Connector 397 passes through aperture 400 of mounting plate 132 and channel 384 of bellows assembly 393 to engage channel 388 in base plate member 390. Channel 388 is surrounded by a collar 386 that is housed within a larger channel 384. Plate 399 is disposed on elongated members 396.
Tube assembly 401 includes a shaft 403 and annular flange 405. A threaded end 404 connects connector 397 inside the threaded end of shaft 403 and the base of tube assembly 401 is operatively disposed within the channel of plate member 390. Tube assembly 401 passes shaft 171 through the top surface of annular flange 405 which is surrounded by a threaded end 411 and an outer collar 409.
FIG. 6 illustrates the gear assembly within housing 127. The gear assembly includes an outer cylindrical wall 151 mounted onto mounting plate 132. The mounting plate is attached by means of bolts 157 to the top portion of housing 125. Interior 153 of wall 151 receives drive shaft 171 from housing 125 and drives pinion gear 167. Pinion gear 167 engages with the teeth of gear 165 which gear is coupled via shaft 135 to drive gear 163. The teeth of drive gear 163 mesh with the teeth of gear 161 mounted on shaft 133. Shafts 133 and 135 each have an upper extending end which extends through the upper surface of plate 131 into enclosure 23 to engage the rear end of a corresponding one of arm segments 139 and 141, as shown in FIG. 4. In this manner, extension and retraction of the arms are accomplished by the respective rotation of shafts 133 and 135 and via the rotation of gears 161 and 163, respectively.
FIG. 7 shows robot arm 41 in greater detail. Rear end 175 of each of the pair of robot arms includes a member 181 having an aperture 177 for engaging the extending portions of shafts 133 and 135. Rear end 175 includes a hex head self-locking clamp mechanism with a head 183 having an elongated, externally-threaded stem 185 for engaging a hollow, internally-threaded retainer drum clamp 187 to tighten or loosen the grip of member 181 about respective shaft 133 or 135. Furthermore, each of rear ends 175 of arm segments 139 and 141 includes a gas inlet comprising an elongated cylindrical stem 189 and an interior channel 191 communicating with hollow interior 186 of arm segments 139, 141. Inlet channel 191 is connected to a source of gas, such as hydrogen or nitrogen.
Each intermediate portion of arm segments 139 and 141 includes a generally cylindrical wall 188 and each has a hollow interior 186 or at least a hollow interior gas-conducting passage within the hollow interior. An arm mid-connector 193 includes shaft 197 for engaging an opposing mid-connector 195 of upper arm assemblies 199 and 201, respectively. Each of the upper arm assemblies has a substantially hollow interior 203 and a cylindrical wall 205. At each end of upper arm assemblies 199 and 201 is disposed an end plate 207, 209, respectively. Each of end plates 207, 209 is connected to a Bernoulli mounting plate 211 through gear segment 213 and gear segment 215, respectively. The teeth of the gear segments mesh at a point designated by numeral 217. A retainer bushing 219 includes a gas passageway 221 and a pair of apertures 223.
FIG. 8 shows a side view of one of robot arms 41. Rear end 175 includes drum clamp 187 having a threaded internal aperture 227 extending therethrough. The rear end also includes a gas flow inlet, stem 189 having an inlet channel 191 for communicating with an external source of gas. The front end of arm segment 139 is connected via mid-connector 193 and shaft 197 to mid-connector 195; bearings 223 are retained about shaft 197 and by a nut 231.
An intermediate portion of arm assembly 201 includes a filter 229 operatively disposed within interior 203 for filtering particles from the flow of gas passing therethrough. The gas is channeled through end plate 209 and then upwardly through a bearing 219 via passageway 221 to mounting plate 211. FIG. 9 illustrates the front end of robot arms 41, mounting plate 211 and wand assembly 43. Arm assemblies 199 and 201 are coupled to mounting plate 211 via end plates 207 and 209, respectively. The wand assembly is connected to the under surface of mounting plate 211 by a wand retainer plate 299. The wand assembly includes a gas distribution plate 293 and a gas outlet plate 295 which may be referred to collectively as the head unit. Each of the plates 293 and 295 is substantially flat or planar and is adapted to have one surface mounted flush against a surface of the other. Gas distribution plate 293 has a flat upper surface 296 and gas outlet plate 295 has a flat or planar top or upper surface 298. Preferably, plates 293 and 295 are made of fused quartz and acid-etched with hydrofluoric acid to greatly reduce a tendency to produce or attract particles which might contaminate or damage the wafers.
FIG. 10 shows a sectional side view of arm assembly 201 of one of the pair of robot arms 41, including end plate 209 and mounting plate 211. Interior 203 of the robot arm includes a gas-conducting passageway which communicates with a smaller diametered cylindrical gas inlet passageway 245 in the front of end plate 209. End plate 209 includes a metal, preferably stainless steel or some similar structural material, body 241 secured within the interior walls of arm assembly 201. O-ring gaskets 267 are housed in annular slots 265 to prevent the escape of gas. Arm assembly 201 is connected to end plate 209 and body 241 of the end plate 209 via fastener 269.
A relatively narrow, cylindrical gas-conducting conduit 247 communicates with passageway 245 and a vertical gas passageway 249. Passageway 249 is surrounded by a lower retainer 277 and an upper retainer 279. A collar 291 and bearing 275 surrounds passageway 249 and are connected via threaded fasteners 281 to mounting plate 211. Another fastener 271 is used to secure gear segment 215 to body 241 of end plate 209.
The gas flows through a narrow, gas-conducting, slanted passageway 247 to horizontal gas collection chamber 278 and then flows vertically upwardly through passageway 249, through an outlet 283, and into a horizontal passageway 251 of mounting plate 211. The mounting plate includes a body 273 having a generally cylindrical recess 255 formed in the front end. Floor 266 of recess 255 includes a gas outlet aperture 263. The gas outlet aperture 263 communicates with an inlet 317 in upper surface 296 of gas distribution plate 293. Gas inlet 317 communicates through gas distribution plate 293 via channel 329 to a bottom gas outlet 321. Floor 256 of recess 255 has an annular filter 261 disposed therein for filtering particles from any gas passing therethrough via the inlet 257 and aperture 263. An annular member 292 is positioned with an annular flange 294 disposed about the outer peripheral edge portion of the filter 261. Upper shoulders of the annular member 292 contain an annular groove 288 for housing an O-ring seal 287. Annular member 293 is compressively held within recess 255 via a cover 289 secured within the opening 285 for replacing filter 261. The gas flows horizontally through the rear portion of mounting plate 211 via passage 251 and then passes downwardly through short, narrow, slanted passageway 253 into recess 255 about annular flange 294. The gas then passes through inlet 257 of the annular flange and enters into hollow central cylindrical cavity 259 from whence it passes vertically downwardly through aperture 263 to gas distribution plate 293.
FIG. 11 shows the front end portion of robot arm 41, mounting plate 211 and wand assembly 43. The connection between arm segment 139 and arm assembly 201 includes mid-connector 193, mid-connector 195 and shaft 197 therebetween. Arm segment 139 is attached to mid-connector 193. The mid-connector includes a cylindrical body 430 integral with a rectangular block 427. A sleeve 432 surrounds body 430. The cylindrical body terminates at gas inlet 421. Gas travels from the gas inlet through a cylindrical central passageway 423 to a relatively small circular gas outlet 425. Outlet 425 communicates through a narrow passageway 422 with a second gas outlet 429.
Block 427 of the mid-connector 193 includes a cylindrical channel 433 for housing a gas inlet sleeve 431 therewithin the interior thereof. Sleeve 431 includes a channel 434 communicating with outlet 429 of gas passageway 422 through an aperture (not shown) in the cylindrical wall of sleeve 431. Sleeve 431 is housed within a cylindrical channel 433 of block 427 of mid-connector 19 via a bottom seal 435, a collar 437, a washer 439, and a nut 441, each of which has a central aperture for receiving at least threaded end 451 of shaft 197. Threaded end 451 of shaft 197 is threadedly engaged with nut 441. To secure the upper end of sleeve 431 within channel 433, an upper seal 435, an upper collar 443, and an upper washer 445 are provided.
Shaft 197 includes a shaft 452 having a threaded end 451 supporting an outer sleeve clamp 453. An inner sleeve clamp 455 is secured to the bottom of body 460 of mid-connector 195. Midconnector 195 has a vertical cylindrical channel 459 extending therethrough and a top opening 457. This portion receives at least a portion of the top of shaft 197 such that arm segment 139 and arm assembly 201 are articulated or rendered pivotable about shaft 452. Mid-connector 195 also includes an integral cylinder 464 surrounded by a sleeve 463 and defining channel 466. Channel 466 connects to the mid-portion of arm assembly 201 and conveys a flow of gas from channel 466 to interior 203 of arm assembly 201. Interior 203 of the arm assembly 201 is defined by inner sleeve 469 and outer sleeve 467.
The cylindrical plug 473 of end plate 209 is disposed within sleeve 467 and attached through the drum clamp via apertures 476 and 478. End plate 209 also includes a partial cylindrical end 474 which is sized to be secured to the front of plug 473. Cylindrical end 474 supports a generally planar body 472 having a flat upper surface 475. The end plate contains a plurality of apertures 477 for receiving fasteners 495.
Body 472 includes a generally hollow cylindrical recess 479 therein. The recess is adapted to receive lower retainer bushing 481 therein. Bushing 481 includes a pair of outer apertures 483 adapted to receive screw fasteners therethrough and a central channel 485 which forms a vertical gas passageway for the assembly. A bearing 487 having a hollow interior 488 is housed over the end portion or annular flange of lower retainer bushing 481. The upper portion of the interior 488 of bearing 487 is adapted to receive an upper retainer bushing 491. Bushing 491 also includes a central gas channel 485 and a pair of fastener-receiving apertures 483 on either side of the channel. The top of retainer bushing 491 is adapted to be received within central aperture 497 of gear segment 215. The gear segment includes a body 496 having a plurality of gear teeth 498. A straight edge 600 and intersecting edge 602 form the other sides of gear segment 496. The gear segment is provided with a plurality of apertures 499 for receiving fasteners 495.
Mounting plate 211 includes a generally rectangular blocklike member 494 having a first relatively thin, generally rectangular, rear part 493 and a second somewhat thicker, generally rectangular, front part 500. Threaded fasteners 523 extend through a plurality of apertures 507 in rear part 494 and apertures 497 of body 496 to engage apertures 483 of upper and lower bushings 491 and 483. A gas passage 511 (of which the exterior is shown) passes longitudinally through the rectangular rear part of mounting plate 211 for receiving the gas by communicating with central aperture 485 of upper bushing 491.
Passage 511 extends into front part 500 and then through a gas inlet 503 into a generally cylindrical cavity 501. Cavity 501, including a cylindrical wall 502, has a floor 504 which is provided with a plurality of interconnecting gas outlets 505. Threaded apertures 509 in floor 504 receive conventional threaded fasteners (not shown) passing through apertures 527 of cover plate 525 for closing the top of cavity 501. Gas inlet 503 is disposed a predetermined distance vertically above outlets 505, and a disk-like filter element 515 is placed on the bottom of the cavity to filter any gas passing through the cavity from inlet 503 to outlet 505. Above filter 515, a filter plunger 519 is disposed within cavity 501, and on top of the plunger is seated an O-ring seal 517 which fits about an annular collar portion of the plunger. Cover plate 525 is placed over top surface 512 of front part 500 to retain plunger 519 and filter 515 in place within cavity 501 while preventing escape of gas from the cavity. Outlets 505 of cavity 501 pass through bottom 510 and communicate with aperture 531 in a central portion of gasket 529, which gasket has a plurality of apertures 533 on the edge portions for receiving conventional fastener means. Bottom surface 532 of gasket 529 is adapted to be placed over the rear end of upper surface 296 of gas distribution plate 293 to align apertures 533 with apertures 313 of the gas distribution plate and gas passage aperture 531 with ga inlet aperture 319 of the upper gas distribution plate.
Gas distribution plate 293 includes a generally planar upper surface 296 and a relatively planar lower surface 333. The top surface includes aperture 319 proximate rear end 305. A plurality of apertures 313 are included on both rear edges for securing gas distribution plate 293 to bottom 510 of front part 500 of mounting plate 211 through apertures 533 of gasket 529.
The portions shown in dotted lines represent the array or pattern of gas distribution channels or grooves formed on lower surface 333 of gas distribution plate 293. The pattern of gas distribution grooves includes a first elongated longitudinal side groove 323, a second elongated longitudinal side groove 327 and a lateral groove 331 connecting the diverging ends of the side grooves. Side grooves 323, 337 and lateral groove 331 form an isosceles triangle having an apex terminating in a common reservoir or channel 329 communicating with aperture 319 in gas distribution plate 293. A central, elongated, longitudinal channel or groove 325 may be provided to bisect the isosceles triangle along lateral groove 331 at its mid-portion. The gas supplied to aperture 319 is distributed to each of grooves 323, 325 and 327 and therefrom to groove 331.
Gas outlet plate 295 includes a relatively planar upper surface 298 and a relatively planar lower surface 355. Apertures 341 proximate rear end 343 are adapted to be aligned with apertures 537 of retainer plate 539, forward apertures 313 of gas distribution plate 293, forward apertures 533 of gasket 529, and a forward pair of apertures 509 in front part 500 of mounting plate 211. Fastener means passed through these apertures secure gas distribution plate 293 and gas outlet plate 295 flush against one another in a sandwich-type configuration.
Upper surface 298 of gas outlet plate 295 includes a geometric pattern 601 for gas distribution. Each of the outlets is shown on upper surface 298 of gas outlet plate 295 as including a circular opening contained on or within a boundary of pattern 601. The pattern can be thought of as being similar to a four-sided geometric figure such as a truncated isosceles triangle. The base of the triangle can be thought of as existing between the imaginary intersections defined by points 611 and 613 and interconnected by a base 603 of triangle 610. The sides of the triangle can be thought of as terminating at rear end 343 of gas distribution plate 295. An imaginary line between gas outlets located on the opposed sides of the triangle define truncated top 605. The sides of triangle 610 coincide with the geometric pattern of grooves on lower surface 333 of gas distribution plate 293.
Side 607 of truncated triangular pattern 601 is connected between imaginary intersection point 613 and outlet 361 while opposite side 609 of truncated triangular pattern 601 is connected between imaginary intersection point 611 and outlet 366. This forms a truncated right isosceles triangle having base 603, truncated top 605, and pair of sides 607, 609.
A pattern of seven gas flow outlets are located or disposed on the border defining the truncated triangle. A first outlet 361 is formed at the intersection of side 607 with top 605 and outlet 366 is formed at the opposite end of top 605. A third gas outlet 362 is disposed on side 607 closer to imaginary intersection 613 than to outlet 361. A fourth gas outlet 365 is disposed on side 609 closer to imaginary intersection 611 than to outlet 366. A fifth outlet 363 is formed on base 603 between the imaginary intersection 613 and the longitudinal axis of wand assembly 43. Equally spaced on the opposite sides of the longitudinal axis is a sixth gas outlet 364 located approximately in the middle between the longitudinal axis and imaginary intersection 611. Lastly, a seventh gas flow outlet 367 is disposed on the longitudinal axis at the midpoint of top 605.
Each of outlets 361, 362, 363, 364, 365, 366 and 367 communicates with a corresponding gas flow outlet on lower surface 355 of gas outlet plate 295, and each is interconnected therewith through a slanted or tapered intermediate channel portion. The tapered channel connecting the laterally displaced upper and lower outlets enables the seven gas flow outlets located on the periphery of pattern 601 to direct the gas flow substantially radially outwardly from a central portion of the pattern so that the gas flow is directed substantially radially outwardly across the top surface of wafer 81 to be picked up and to provide the necessary conditions to effect application of the Bernoulli Principle. The gas flow across the top surface of the wafer creates or establishes an area, volume, or zone of relatively low pressure between lower surface 355 of gas outlet plate 295 and the top surface of wafer 81 with respect to the pressure existing at the bottom surface of the wafer. This pressure differential serves to lift the wafer without any physical contact whatsoever between wand assembly 43 and the top or bottom surfaces of wafer 81.
Furthermore, this pattern provides a continuous outwardly sweeping flow of gas across the top surface of the wafer which greatly reduces the number of particles or contaminants which can collect thereon. Some very slight, soft contact can occur between two spaced apart areas on the outer peripheral rim of wafer 81 and a pair of depending locators 543. Locators 543 are disposed on the rear end of lower surface 355 of gas outlet plate 295 adjacent sides 345 and 347 thereof. An important function of the array of gas outlets is to bias the gas flow to draw the wafer slowly rearwardly under gas outlet plate 295 until the wafer's outer peripheral edge make soft contact with front sides 542 of locators 543. This soft gentle contact is not between the top surface of the wafer and the bottom surface of gas outlet plate 295, but only with two small areas on the outer peripheral circumference of the wafer and locators 543. The above-mentioned rearward horizontal bias results from the orientation of the gas outlets in the pattern in which only two of the seven outlets are radially outwardly directed in a forward direction whereas five of the seven outlets are radially outwardly directed in a rearward direction. This creates a horizontal component of force tending to urge the picked-up wafer rearwardly until it makes soft contact with locators 543.
When lower surface 333 of gas distribution plate 293 is placed over and flush against upper surface 298 of gas outlet plate 295, all of outlets 361, 362, 363, 364, 365, 366 and 367 are operatively disposed directly beneath the pattern of grooves 323, 325, 327 and 331 formed on lower surface 333 of gas distribution plate 393 for supplying a flow of gas thereto.
Additionally, a central outlet 368, which is supplied with gas from central longitudinal groove 325 in lower surface 333 of gas distribution plate 293, is located approximately in the center of the geometric pattern along the longitudinal axis of gas outlet plate 295 and is, contrary to the other gas outlets, disposed at a 90° angle straight through the gas outlet plate. The flow of gas from this outlet serves to aid in substantially reducing or eliminating turbulence, rapid vertical oscillations or wafer dribbling, and in substantially totally eliminating the pick-up of contaminant particles which would otherwise result from a "vacuuming effect".
Lower retainer plate 539 is disposed beneath lower surface 355 of gas distribution plate 293 and apertures 537 are aligned with apertures 341 of gas outlet plate 295, apertures 313 of the gas distribution plate, apertures 533 of upper retainer plate 529 and the apertures in lower surface of front part 500 of mounting plate 211. Conventional fasteners secure these elements securely together in a sandwich-like manner. Tape 535 with corresponding aperture 538 insures a firm contact between upper surface 536 to lower surface 355. Fasteners, not shown, pass upwardly through the assembly and screw into the bottom of mounting plate 211. The removal of a few fasteners enables one wand assembly for use with a wafer of a first diameter to be easily interchanged with another wand assembly for use with a wafer of another diameter.
FIG. 12 shows lower surface 333 of gas distribution plate 293. Aperture 319 communicates with inlet 317, which inlet communicates via outlet 321 with the commonly connected ends of the grooves. The commonly connected or overlapping ends of the groove form channel 329 (discussed above) and the gas from outlet 321 passes into the channel from whence it is fed into and along each of the plurality of grooves.
FIG. 13 shows a sectional end view of lower surface 333 of gas distribution plate 293. The gas distribution plate includes a single, integral, substantially flat member 301 of fused quartz and has a relatively planar top surface 302 and a relatively planar lower surface 333. Sides 303 and 304 represent the sides between which the section is taken, to illustrate the cross section of grooves 323, 325 and 327.
FIG. 14 shows a longitudinal cross section of the gas distribution plate 293. Rear end 305 is disposed across the longitudinal axis which terminates at front end 311. The front end includes a relatively planar front edge 337 of flat lower surface 333, a tapered top surface 335, and a pointed tip 339. Aperture 319 can be seen as being operatively disposed in upper surface 296 of ga distribution plate 293 proximate rear end 305. Outlet 321 communicates with aperture 319 through channel 329. The present section is taken through groove 325. At the end of the central longitudinal groove 325, the intersection with lateral groove 331 is shown.
FIG. 15 shows a top view of gas outlet plate 295. The gas outlet plate includes an upper surface 298, a relatively curved rear end 343, a pair of relatively straight sides 345 and 347, a pair of relatively straight front ends 349 and 351, and a curved central front edge 353. Upper surface 298 of gas outlet plate 295 is relatively planar and includes only a plurality of outlets 361, 362, 363, 364, 365, 366 and 367. These seven outlets define pattern 601 while the common relief outlet 368 is disposed in a central portion of the pattern for use as previously described. Upper surface 298 better illustrates the slope, taper or slant of the gas outlets and it will be noted that the flow is generally radially outward from the approximate center of pattern 601 so as to provide a continuous outwardly sweeping air flow for keeping particles off the top surface of the wafer while simultaneously providing the area of decreased pressure for enabling the Bernoulli Principle to be used to lift or pick up the wafer without physical contact. Since five of the seven outlets are directed horizontally rearward, the wafer is slowly urged horizontally rearwardly until it abuts locators 543.
FIGS. 16 and 17 illustrate the slanted channels described with respect to FIG. 15. The apertures are shown as having a circular inlet 371 on upper surface 298 of gas outlet plate 295, a circular outlet 375 on lower surface 355 and a sloped interconnecting channel 373. Similarly, the oppositely sloped gas outlets shown in FIG. 17 can be considered as having a circular inlet 377 in upper surface 298, a circular outlet 381 in lower surface 355 and a sloped, slanted or tapered interconnecting channel 379. The particular slope and orientation of the channel will determine the direction of gas flow from lower surface 355 of gas outlet plate 295 and hence can provide the desired substantially radially outward flow for maximizing the efficiency of the pick-up operation while simultaneously minimizing particulate contamination.
FIGS. 18 and 19 illustrate yet another embodiment of the wafer handling system shown in FIG. 1 and add additional means for reducing particular contaminants in the system. Enclosure 23 includes a top surface 47 and a floor 45 and a hollow interior 25.
As previously described, a portion of the drive assembly, such as gear housing 569, is coupled through a vacuum seal to plate assembly 39 which serves to drive a pair of articulated robot arms 41 having a pick-up wand assembly 43 mounted at the front end thereof for picking up and carrying a semiconductor wafer 81. The rear ends of the articulated robot arms 41 are coupled to shaft 133 extending through floor 45 and plate assembly 39. A supply station, supply port or purge box (29) includes an elevator 551 for carrying a cassette holding a plurality of wafers (not shown) in a horizontal position. Elevator 551 moves vertically in a step-wise linear manner to accurately position a wafer at access slot 35 through which the robot arms pass to pick up a wafer contained in the cassettes for delivery to reactor 27.
In the embodiment shown in FIG. 18, a source 557 of ultraviolet (UV) infrared rays 560 is provided. The source may be any conventional tube or other source of ultraviolet rays chosen to radiate in the desired spectral range such that the UV rays pass readily through top surface 47; the top surface is preferably made of fused quartz which is transparent to UV radiation at the radiating wavelength. Source 557 is provided exterior of the top surface and UV rays 560 pass through the quartz and bombard the central area in interior 25 to continually irradiate robot arms 41, wafer pick-up wand assembly 43 and the top surface of the wafer 81 carried thereby whenever the robot arms are in the home position. Since the plates of the pick-up wand assembly are also made of quartz, the UV rays pass readily therethrough to bombard the top surface of the transported wafer and the area thereabove. Bombardment with ultraviolet rays 560 neutralizes the charge of contaminant particles within interior 25 of enclosure 23. By removing the charge, the particles are less likely to interact with, stick to, be attracted to, or accumulate on the top surface of wafer 81. Thus, bombardment with ultraviolet rays reduces particle contamination and further improves cleanliness of the wafer handling system.
The UV source 557 is shown as having one terminal connected to a node 558 which in turn is connected via lead 555 to one output of a power source 553. The power source is also connected through a lead 556 to a second node 559. Node 559 connects to the opposite end terminal of tube 557 to supply power to the tube for generating the ultraviolet rays 560.
Alternatively, a tube 561 can be placed within interior 25 of enclosure 23 adjacent top surface 47. The ultraviolet rays 563 perform the bombardment necessary for neutralizing charged particles which might otherwise contaminate wafer 81. Tube 561 is supplied power via lead 565 coupled between one end terminal of the tube 561 and node 558, while node 559 is coupled via lead 556 to the opposite end terminal of the tube 561.
FIG. 19 provides another embodiment of the concept shown in FIG. 18. Enclosure 23 includes upper surface 47 which may be a quartz panel, and a floor 45. Gear housing 569 is connected through a vacuum seal from beneath the surface of floor 45 to interior rotatable plate assembly 39. The shaft 133 couples the gear housing with the rear end of a pair of articulated robot arms 41 to extend and retract them. Pick-up wand assembly 43 is shown as depositing wafer 81 onto a rotatable susceptor 573 mounted on a pedestal 575 having a rotatable shaft 577. The assembly, including susceptor 573, pedestal 575 and shaft 577, may be upwardly and downwardly positionable and rotatable, as desired. Robot arms 41 are in the fully extended position and to pass through gate 579 communicating with interior 571 of reactor 27. Top 581 and bottom 583 of reactor 27 are made from quartz to be transparent to ultraviolet radiation of a particular wavelength or range of wavelengths.
A source of UV radiation, tube 592, is operatively mounted or disposed on the exterior of top 581 and arranged to irradiate the interior proximate the entrance or between the gate and the susceptor of the reactor 27 to neutralize charged particle contaminants adjacent access gate 579 and within the reactor. Tube 592 receives power from a power source 587 and connected through a first lead 588 and a node 590 to one terminal of tube 592. The power source is also connected through a lead 589 to a node 591 and then to the other terminal of the tube.
In an alternate embodiment, the UV source or tube 596 is operatively mounted or disposed within the interior 571 of reactor 27 adjacent top 581. Tube 596 produces UV radiation (rays 597) for bombarding the path of wafer 81 from access gate 579 to susceptor 573 to neutralize charged particles and prevent them from accumulating on the wafer surface. Tube 596 has one terminal connected via lead 594 to input node 590, and its opposite terminal connected via lead 595 to input node 591 to obtain power from power source 587.
In the preferred embodiment of the present invention, the pair of articulated robot arms are much stronger and more accurately positionable than was heretofore possible by constructing them of stainless steel and providing them with a circular cross section. The length of the robot arms at their fully extended position is significantly longer than the 18 inches normally possible and lengths of at least 25 inches are routine.
Both gas distribution plate 293 and gas outlet plate 295 of pick-up wand assembly 43 are manufactured from fused quartz and acid-etched and polished with an acid such a hydrofluoric acid. The etching and polishing not only smooths and polishes the grooves and apertures formed in the plates to prevent particles from being deposited thereon, but also polishes all the surfaces to prevent particles from being attracted to or accumulating on the surfaces and therefore reduce the chance of contaminating or damaging the wafer. The use of quartz for the wafer pick up wand assembly enables it to be used to pick up relatively hot substrates. Normal processing in the reaction chamber raises the wafer temperature to approximately 1150° C. The temperature cools down to below 1000° C. in about one minute. A very short time later, when the wafer temperature is lowered to 800° C.-900° C., the pick up wand assembly can lift the hot wafer without damage thereto.
The walls of enclosure 23 are preferably made of a noncontaminating material such as anodized aluminum or the like and a window, preferably made of an ultraviolet-transparent material, such as fused quartz, is provided therein for observation purposes. The interiors of the robot arms include a continuous gas passage therethrough so that gas is supplied from an external source through the robot arms to the gas distribution plate 293. The gas used is dependent upon the operation to be effected; in epitaxial deposition system the gas will be either hydrogen or nitrogen, depending upon the particular operation then being conducted. Gas can be supplied from any conventional gas container or source.
The present invention provides three distinct but related advantages. The first advantage is to provide a wafer pick up and delivery apparatus for use in a high speed, continuous, single wafer processing system which apparatus will not damage the wafer. The second advantage is to provide every possible means of reducing or eliminating particulate contaminants to the order of two or three particles per wafer. The third advantage is to provide for a "hot" pick up wherein processed wafers can be picked up within a few minutes after processing.
A typical operation of the present invention may be summarized as follows. Robot arms 41 are normally maintained in the home position. To pick up a wafer from station 29, plate assembly 39 rotates until pick u wand assembly 43 faces access slot 35 of the station; the robot arms are maintained in the home position during rotation. Once the rotation stops, robot arms 41 are extended to pass the pick up wand assembly through the access slot and to a cassette for picking up a wafer and translating motion is stopped. The wafer is picked up when the flow of gas is commenced after the robot arms are stationary above the wafer to be lifted. After pick up, the robot arms are retracted to the home position and held in that position while the plate rotates to position the pick up wand assembly in allignment with the entrance to reactor 27. The robot arms are extended to position the wafer on the susceptor therein and the flow of gas is stopped resulting in release of the wafer and deposit of the wafer on the susceptor. The robot arms are withdrawn to the home position while the wafer is processed. The robot arms are extended back into the reactor to pick up the processed wafer while it is still hot. To lift the wafer, the flow of gas is initiated; after the wafer is picked up, the robot arms retract to the home position. Plate assembly 39 is rotated until the loaded pick up wand assembly is positioned in front of the access slot to a station. To deposit the wafer within a cassette housed in the station, the robot arms are extended. Terminating the flow of gas will release the wafer upon the cassette. In the final step, the robot arms retract to the home position to position them ready for a further cycle. It may be noted that the flow of gas is intermittent to minimize turbulence of particulate matter. | Wafer handling apparatus operating under the Bernoulli principle to pick up, transport and deposit wafers, which apparatus includes a plate having a plurality of laterally oriented outlets and a central outlet for discharging gas in a pattern sufficient to develop a low pressure enviroment to pick up the wafer while bathing the wafer in radially outflowing gases to prevent intrusion and deposition on the wafer of particulate matter in suspension. | 8 |
CLAIM OF PRIORITY
[0001] The present application claims priority from Japanese application JP 2004-234335 filed on Aug. 11, 2004, the content of which is hereby incorporated by reference into this application.
FIELD OF THE INVENTION
[0002] The present invention relates to a semiconductor device and a semiconductor manufacturing method for the same device, and more particularly to a semiconductor device and a semiconductor manufacturing method ideal for nonvolatile semiconductor memory devices mounted on the same substrate with semiconductor devices possessing logic calculation functions typified by microcomputers.
BACKGROUND OF THE INVENTION
[0003] Multi-function semiconductor devices can be fabricated by mounting a semiconductor nonvolatile memory cell on the same substrate with a logic semiconductor device. These multifunction semiconductor devices are widely utilized as built-in type microcomputers in industrial machinery, home appliances, and automobiles, etc.
[0004] These types of nonvolatile memories generally store a program required by that microcomputer are used to read out that program whenever needed. The cell structure of the nonvolatile memory for mounting along with these types of logic semiconductor devices are described as split-gate memory cells made up of selection MOS transistors and memory MOS transistors.
[0005] In order to employ source-side-injection (SSI) possessing good charge injection efficiency, this structure is designed for joint applications including high-speed writing, and providing a reduction in peripheral circuit area comprised of low-voltage transistors with a small device area as the memory cell selection transistors and transistors connecting to those memory cell transistors. Technical documents of the known art relating to this technology include for example, patent document 1, patent document 2, non-patent document 1, non-patent document 2, and non-patent document 3.
[0006] Method for retaining the electrical charge within the memory MOS transistor are: the floating gate type method (patent document 2, non-patent document 1) where the electrical charge is stored in electrically isolated conductive polysilicon, and the MONOS method (patent document 1, noon-patent document 2) for storing the electrical charge in an insulator film possessing properties similar to charge trapping properties of silicon nitride film.
[0007] The floating gate method possesses good charge retention characteristics and is widely utilized in large-capacity data storage flash memories and program storage flash memories for cellular telephones, etc. However, maintaining the charge coupling rate needed for controlling the voltage potential became more difficult in the floating gate as device integration became advanced, and the structure became more complicated. The oxide film enclosing the floating gate must be at least 8 nanometers thick in order to suppress leakage of the stored electrical charge, and the floating gate is approaching its miniaturization limits in term of high-speed and high-integration. If there is a flaw causing a leak path in even one position on the oxidized film around the floating gate, then the electrical charge retention of the floating gate drastically decreases.
[0008] In the MONOS system on the other hand, the electrical charge retention is generally poor compared to the floating gate, and the threshold voltage tends to drop with the logarithm of the time. Therefore, while this method has been known from a long time past its use is limited to only certain products.
[0009] However, a localized charge trapping method is utilized to hold the electrical charge in an insulating element so that even if there are several leak paths, there is few loss of the overall charge being held so the MONOS method is strongly resistant to defects in the oxidized film. Oxidized film thinner than 8 nanometers can therefore be used so this (MONOS) method is more suited to miniaturization and the probability of a drastic drop in the charge retention due to a defect is low so reliability can be easily predicted. Moreover, the memory cell structure is simple and can be easily mounted with logic circuits so that this method is again the focus of attention in recent years as device scaling is advanced.
[0010] The split-gate structure which is particularly well suited for scaling, is a side wall structure (patent document 1, non-patent document 2) in which a side wall is utilized to form a MOS transistor gate electrode from one of the MOS transistors utilized for self-alignment. In this case, the gate length of the transistor formed by self-alignment can be formed less than minimum lithographic resolution dimensions so that a tiny memory cell can be formed compared to the method of the conventional art which forms two transistors with photomask.
[0011] Even among split-gate memory cells using self-alignment, those cells formed with a MONOS structure on the self-aligning gate as disclosed for example in patent document 3, non-patent document 2, are ideal to be embedded with high speed logic circuits.
[0012] A cross sectional view of this memory cell is shown in FIG. 1 . The memory gate electrode 11 is formed from an ONO film (oxide film/nitride film/oxide film) of SiO 2 film 13 , SiN film 14 , SiO 2 film 15 on the side wall of the selection gate electrode 12 and a polysilicon electrode with a side wall structure. A silicide layer 16 is formed on the upper section of the diffusion area 1 and 5 , and selection gate electrode 12 , and memory gate electrode 11 .
[0013] In order to first form the selection gate electrode of this memory cell structure, the gate oxide film of the logic circuit section transistor can be formed simultaneously, with the selection gate electrode in a state where the silicon substrate surface (interface) is of good quality. A sensitive high-speed operation thin-film gate transistor with good interface quality can be formed first so the selection transistor and the transistors of the logic circuits possess better performance. The loading (reading) of the stored information can be performed just by high-performance selection transistor operation and their connecting transistors can all be thin-film low-voltage types so fast loading (read-out) can be achieved and the circuit area is reduced.
[0014] The memory cell array structure possessing these split-gate type MONOS memory transistors is shown in FIG. 2 . Each cell and the opposing memory cell jointly possess a semiconductor region (highly doped region, hereafter called the source) adjoining the memory gate electrode 11 ; and the source line 1 is in parallel with the word line. Two types of word lines for the selection gate 3 and for the memory gate 2 extend in parallel toward the word lines. The bit lines 4 perpendicular to these word lines, connect to the semiconductor region (highly doped region, hereafter called the drain) adjoining the selection gates 12 of each cell.
[0015] Voltage conditions during typical operation are shown in FIG. 3 . In the write operation, the semiconductor surface directly below the selection gate 3 is set to weak inversion state with approximately 12 volts and 5 volts applied to memory gate 2 and the source 1 by the source side injection method (SSI method), and hot electrons are injected into the silicon nitride film serving as the charge trapping film of the ONO film, by the strong electrical field occurring between the semiconductor substrate surface and the memory gate 2 .
[0016] In the erase operation, the hot hole injection method (BTBT method) via a tunnel between bands is utilized. A voltage of approximately −5 volts is applied to the memory gate 2 and 7 volts is applied to the source 1 as a reverse bias, and the strong electric field on the edge of the diffusion area generates hot holes via the tunneling between bands, and these hot holes are injected into the memory gate 2 . To read information, 1.5 volts is applied to both the memory gate 2 and selection gate 3 , and 1 volt is applied to the drain (bit line 4 ), and the read information determined by amplitude of the current flowing in the drain (bit line 4 ).
[0017] The process for manufacturing the memory cell containing split-gate type MONOS memory transistors is characterized by good compatibility with the standard CMOS process, and can be used to mount components such as microcomputers on the semiconductor memory. The process flow compatible with when mounting via the standard CMOS process is shown utilizing FIG. 4 through FIG. 10 .
[0018] FIG. 4 is a cross-section view of the stage for forming the gate electrode structure of polysilicon on the silicon substrate. Though not shown in the figure, in the previous stage, the structure of the field isolating insulator is formed utilizing the conventional method, and the gate insulator film and polysilicon gate electrode material films are formed. The memory area selection transistor and the logic area transistors have the gate insulator in common. The reference numeral 12 denotes the selection gate electrode, and the reference numeral 17 denotes the gate electrode for the logic area transistor.
[0019] The stage for forming the three-layer ONO film 18 structure of SiO 2 film, SiN film, SiO 2 film is next shown in FIG. 5 .
[0020] The second polysilicon is deposited as the memory gate electrode material and, etchback performed by dry etching to leave polysilicon film as the side wall electrode only on the side of the gate electrode as shown in the state in FIG. 6 . The reference numeral 20 denotes the contact extension, reference numeral 40 is the memory gate side wall electrode removed later, and reference numeral 41 is the logic area side wall electrode removed later. Among the side wall electrodes that were formed, the unnecessary side wall electrode 40 on one side, and the side wall electrode 41 on both sides of the logic area are removed by etching, and when the ONO film whose lower layer of polysilicon was removed, and the ONO film formed on the upper surface of the select electrode 12 are removed the state shown in FIG. 7 is attained. The ONO film formed on the upper surface of the select gate electrode 12 is removed in order to simultaneously silicide the upper surface of the select gate electrode 12 and lower the resistance of the select gate electrode 12 , so that the resistance of the memory gate to be formed is lowered during siliciding.
[0021] At this point, the SiO 2 film forming the side wall of the logic area transistor and the MONOS memory cell is deposited and etched back to form the state in FIG. 8 . Reference numeral 19 is the oxide film side wall. The state where siliciding was performed to lower the resistance of the gate electrode and diffusion area is shown in FIG. 9 . Reference numeral 27 is the silicided section. The first layer of a resistive film 42 is then deposited, and the stage after planarizing and forming of the contact areas is shown in FIG. 10 . The description of the standard process for forming the metal wiring layers of approximately three to six layers is omitted.
[0022] The masks required for embedding nonvolatile memories in the related art can be broadly grouped into masks for ion injection, and structural forming masks. Of these mask types, one structural forming mask is utilized for removing the polysilicon side wall electrode on one side of the selection gate; and another structural forming mask is utilized for forming the wiring contact areas to the memory gate electrode. Of these structural forming masks, the latter mask is intended only for forming the contact area with the wiring, regardless of the fact that the memory gate electrode is formed by self-alignment and essentially does not require a mask.
[0023] The contact forming section is next described in further detail. The layout of the contact forming region (connecting) to the memory gate electrode in the technology of the related art is shown in FIG. 11 . One word line formed from the memory gate and the select gate extends to the device isolation region and forms the contact area.
[0024] In the technology of the related art as shown in FIG. 7 , the ONO film on the upper surface of the select gate 12 must be removed in order to silicide the selection gate electrode 12 and memory gate electrode 11 in the same process. However as shown in FIG. 10 , the first layer of the insulator film 42 is common with on the selection gate electrode 12 and on the memory gate electrode 11 after the siliciding, so that when forming the contact hole on the insulator film 42 for receiving the contact on the memory gate electrode 11 , the surface of the selection gate electrode 12 might become exposed rather than just the surface of the memory gate electrode 11 .
[0025] This unwanted exposure is caused by the fact that the width of the memory gate electrode is approximately 60 nanometers and the memory gate electrode is a side wall electrode that is small compared to the width of the contact hole; and the fact that the selection gate electrode 12 and the memory gate electrode 12 are only separated by a distance 20 nanometers as the thickness of the ONO film 18 ; and the fact that the photolithography alignment error in the process for forming the contact hole is approximately 60 nanometers which is the same as the width of the memory gate electrode 11 .
[0026] When forming the contact hole in this way, and the surface of the memory gate electrode 11 and the surface of the selection gate electrode 12 are exposed within one contact hole, the forming of the contact might cause the memory gate electrode 11 and selection gate electrode 12 to short and disable the nonvolatile memory.
[0027] To eliminate this possibility, a dedicated contact region 20 is formed by photolithography as shown in FIG. 11 . This contact region 20 is formed by utilizing a dedicated mask, and covering just the contact region 20 with photoresist during etchback of the memory gate electrode so that a section with no etchback is formed. The reference numeral 21 is the contact. The line taken along A-A′ in the cross sectional view in FIG. 11 is jointly recorded in FIG. 12 , and the manufacturing process flow for the memory area and the logic area are jointly described in FIG. 4 through FIG. 10 . The contact region 20 can in this way be formed at a position isolated from the selection gate electrode 12 so that the contact 21 for the memory gate electrode 11 as described above, does not connect to the selection gate electrode 12 , and the memory gate electrode 11 is prevented from shorting to the selection gate electrode 12 . In FIG. 11 , the contact region 20 overlaps onto the selection gate electrode 12 however as clearly shown in the cross sectional view in FIG. 12 , an ONO film is formed between the contact region 20 and the selection gate electrode 12 so that because of the electrical insulation, there will be no shorts. A technology for forming a contact auxiliary pattern as a technique for reducing the masks for the split-gate type nonvolatile memory is disclosed in FIG. 1 and FIG. 2 of the patent document 4.
[Patent document 1] JP-A No. 48113/1993 [Patent document 2] JP-A No. 121700/1993 [Patent document 3] JP-A No. 186452/2004 [Patent document 0.4] JP-A No. 326286/2001 [Non-patent document 1] IEEE, 1994 Symposium on VLSI Technology, Review pp. 71-72 [Non-patent document 2] IEEE, 1997 Symposium on VLSI Technology, Review pp. 63-64 [Non-patent document 3] IEEE, 2003 Symposium on VLSI Circuits Digest of Technical Papers, Session No. 16, Academic paper No. 2.
SUMMARY OF THE INVENTION
[0035] A manufacturing process (for mixed mounting of) nonvolatile semiconductor memory devices utilizing the standard CMOS logic process is needed that is capable of reducing the number of masks and capable of jointly using as much as possible the manufacturing steps common to the standard CMOS process.
[0036] The technology of the related art requires a dedicated mask for forming the contact region as previously described and was therefore incapable of utilizing the advantages of the self-alignment method.
[0037] The technology of the related art also had the problem that at least two position alignments made up of position alignment of the mask for installing the contact region, and alignment of the mask for forming the contact holes. Therefore when utilizing a designing a layout that took the photolithographic alignment into account, the clearance between the adjacent word lines was small, and a dense integration of the memory arrays was impossible.
[0038] A technique for reducing masks in split-gate type nonvolatile memories of the related art is disclosed in patent document 4. However, the patent document 4 is only a technology for forming contacts only on floating gates possessing a side wall gate structure and so when a process for siliciding the control gate surface and the floating gate surface was applied, and the contact auxiliary pattern surface was covered by an insulator film after siliciding, then a mask was required in order to selectively form an insulator film on the surface of the contact auxiliary pattern, so that the number of masks could not be reduced.
[0039] Moreover, when the control gate was made a polycide gate in order to lower the resistance of the control gate, the process for siliciding the control gate, and the process for siliciding the floating gate were separate processes so that two siliciding processes were required and therefore the manufacturing process became complex.
[0040] The patent document 4 is technology for forming a contact in a filler section comprised from a section of the floating gate between the contact auxiliary pattern and the control gate. In FIG. 1 of this patent document 4, an electrical short with the control gate might possibly occur when an offset or deviation in the position alignment for forming the contact occurs. Also, as shown in FIG. 2 of patent document 4, when a filler section is formed from multiple contact auxiliary patterns in order to avoid the possibility of an electrical short, the surface area size of the contact auxiliary patterns becomes large so that reducing the pitch width between adjacent control gates becomes impossible.
[0041] A typical example of this invention is shown as follows. Namely, a process for depositing a first conductive film over a semiconductor substrate, and forming a first gate electrode and auxiliary pattern and; a process for forming a first insulator film over the first gate electrode, auxiliary pattern, and the semiconductor substrate and; a process for depositing a second conductive film on the first insulator film and, by etchback of the second conductive film, respectively forming a first side wall electrode via the first insulator film on the side surface of the first gate electrode, as well as forming a second side wall electrode via the first insulator film on the side surface of the auxiliary pattern and; a process for exposing the upper surface of the auxiliary pattern and the first gate electrode by stripping away the first insulator film formed on the auxiliary pattern and the first gate electrode and; a process for siliciding the upper surface of the first gate electrode, the upper surface of the auxiliary pattern, and the surface of the first side wall electrode and; a process for forming a second insulator film over the auxiliary pattern and the second side wall electrode and; a process for forming at least one or more contact holes on the second insulator film, and exposing the auxiliary pattern and side wall electrode in the forming of one contact hole and; a process for forming a contact in a contact hole; and the first side wall electrode is contacting the second side wall electrode.
[0042] The representative effect rendered by the above means of this invention is the simplifying of the manufacturing process for semiconductor devices capable of high-speed operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. 1 is a cross sectional view of the MONOS memory cell with a split-gate structure;
[0044] FIG. 2 is a structural view of the memory array for this invention;
[0045] FIG. 3 is a table of typical operating conditions;
[0046] FIG. 4 is a descriptive view of the process flow in the related art;
[0047] FIG. 5 is a descriptive view of the process flow in the related art;
[0048] FIG. 6 is a descriptive view of the process flow in the related art;
[0049] FIG. 7 is a descriptive view of the process flow in the related art;
[0050] FIG. 8 is a descriptive view of the process flow in the related art;
[0051] FIG. 9 is a descriptive view of the process flow in the related art;
[0052] FIG. 10 is a descriptive view of the process flow in the related art;
[0053] FIG. 11 is a view of the layout of the contact area of the related art;
[0054] FIG. 12 is a cross sectional view of the contact area of the related art;
[0055] FIG. 13 is a view of the layout of the contact area of this invention;
[0056] FIG. 14 is a cross sectional view of the contact area of this invention;
[0057] FIG. 15 is a cross sectional view (during application to SAC process) of the contact area of this invention;
[0058] FIG. 16 is a layout view of the memory array of the first embodiment of this invention;
[0059] FIG. 17 is a layout view of the contact area of the first embodiment of this invention;
[0060] FIG. 18 is a concept view of the process flow in the first embodiment of this invention;
[0061] FIG. 9 is a concept view of the process flow in the first embodiment of this invention;
[0062] FIG. 20 is a concept view of the process flow in the first embodiment of this invention;
[0063] FIG. 21 is a concept view of the process flow in the first embodiment of this invention;
[0064] FIG. 22 is a concept view of the process flow in the first embodiment of this invention;
[0065] FIG. 23 is a concept view of the process flow in the first embodiment of this invention;
[0066] FIG. 24 is a concept view of the process flow in the first embodiment of this invention;
[0067] FIG. 25 is a cross sectional view of the contact area in the first embodiment of this invention;
[0068] FIG. 26 is a concept view of the process flow during forming of the contact area in the first embodiment of this invention;
[0069] FIG. 27 is a concept view of the process flow during forming of the contact area in the first embodiment of this invention;
[0070] FIG. 28 is a concept view of the process flow during forming of the contact area in the first embodiment of this invention;
[0071] FIG. 29 is a concept view of the process flow during forming of the contact area in the first embodiment of this invention;
[0072] FIG. 30 is a graph showing conditions required for forming the contact area in the first embodiment of this invention;
[0073] FIG. 31 is a layout view of the contact area of the first embodiment of this invention;
[0074] FIG. 32 is a layout view of the contact area of the second embodiment of this invention;
[0075] FIG. 33 is a concept view of the process flow during forming of the contact area in the fifth embodiment of this invention;
[0076] FIG. 34 is a concept view of the process flow during forming of the contact area in the fifth embodiment of this invention;
[0077] FIG. 35 is a concept view of the process flow during forming of the contact area in the fifth embodiment of this invention;
[0078] FIG. 36 is a concept view of the process flow during forming of the contact area in the fifth embodiment of this invention;
[0079] FIG. 37 is a concept view of the process flow during forming of the contact area in the fifth embodiment of this invention;
[0080] FIG. 38 is a layout view of the contact area of the third embodiment of this invention;
[0081] FIG. 39 is a layout view of the contact area of the fourth embodiment of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0082] The embodiments of this invention are hereinafter described while referring to the drawings.
First Embodiment
[0083] The first embodiment is described while referring to FIG. 1 through FIG. 3 and FIG. 16 through FIG. 30 . The memory cell is a MONOS memory cell with the split-gate structure shown in FIG. 1 , and the array structure shown in FIG. 2 . The voltage conditions for read, write and erase are shown in FIG. 3 .
[0084] A flat layout view within the memory cell array is shown in FIG. 16 . Field isolating insulators 33 are formed on the semiconductor substrate in correctly established arrays. In FIG. 16 , the semiconductor substrate other than the field isolating insulators 33 is the activated region where the selection transistor, memory transistor, source line, and bit line are formed. The reference numeral 12 denotes the gate electrode for the selection transistor. The reference numeral 11 denotes the gate electrode for the memory transistor. The gate electrode 12 and gate electrode 11 are both formed to span the activated region and field isolating (device isolation film). The reference numeral 30 denotes the source line and is formed within the activated region. The reference numeral 52 is the contact forming a section of the bit line and formed on the drain side of the memory transistor and the selection transistor. The section enclosed by the dashed (broken) line 31 in FIG. 16 is equivalent to one memory cell. In other words, the selection transistor and the memory transistor are contained within the memory cell. The memory gate electrodes 11 of the adjacent memory cells are formed facing each other as clearly shown in FIG. 16 , and the selection gate and memory gate are formed bilaterally symmetrical to each other. Though not shown in FIG. 16 , a contact region is formed in the direction (word line direction) that the gate electrode 11 and the gate electrode 12 extend, in order to apply a voltage to the gate electrode 11 of the memory transistor and the gate electrode 12 of the selection transistor; and make contact with the respective gate electrodes on the field isolating insulator film in the device isolation region.
[0085] A flat layout view of the contact region of the memory area is shown in FIG. 17 . Here, D is the device isolation region, and the contact region is within the region D. Also, E is the first memory array region, and Fi is the second memory array F region. A contact region is present between these memory arrays. The section 31 enclosed by the broken (dashed) lines is one memory cell region. The oblique line 62 indicates the active region (device forming region) within the memory array region. A contact auxiliary pattern 22 is formed adjacent to the extended part 35 of the word electrode 12 (word line), and a contact 21 is formed on the memory gate extended part 37 connected electrically by conductive material embedded in both the clearances 36 . Here, the contacts 21 are formed at two locations in different levels in order to array the contact wiring to the adjacent memory gates in parallel with the respective word lines. FIG. 31 shows a flat layout of when the contacts are formed on the selection gate electrode 12 . The reference numeral 61 is the selection gate electrode contact.
[0086] The manufacturing process flow is shown in FIG. 18 through FIG. 24 . A 0.18 micrometer process rule is utilized in the manufacturing. FIG. 18 through FIG. 24 show the memory area (left row) and logic area (center) and the contact area (right row). The layout of the contact area (right row) is expressed by the cross section of B-B′ in FIG. 17 . A cross sectional view of the section C-C′ intersecting this cross section (B-B′) is shown in FIG. 25 .
[0087] FIG. 18 is a cross sectional view of the stages for forming the gate electrode structure 12 made from polysilicon to a height of 250 nanometers, after forming the gate insulator film 6 to a film thickness of 3 nanometers on P-type silicon substrate. Though not shown in the drawing, a shallow trench isolation is formed to a thickness of 350 nanometers in a previous stage. The memory area selection transistor and the logic area transistor have the gate insulator film 6 in common. The contact area is formed on the shallow trench isolation region; and the contact auxiliary pattern 22 is formed from the same polysilicon as the gate electrode structure 12 . Here maintaining the respective distances at a fixed distance is essential during forming of the gate electrode structure 12 and the contact auxiliary pattern 22 and the reason this is essential is related later on.
[0088] An ONO film with a three-layer structure of SiO 2 film (4 nm), SiN film (10 nm), SiO 2 film (5 nm) is next deposited as shown in FIG. 19 over the gate electrode structure 12 and the semiconductor substrate. The silicon nitride film functions as an electrical charge trapping film to accumulate memory transistor electrical charges. Each of the silicon oxide films functions as a potential barrier to the electrical charges to suppress the leakage from the electrical charge trapping film.
[0089] Moreover, as shown in FIG. 20 , a polysilicon film doped with impurities is deposited to a thickness of 75 nanometers over the ONO film in order to form a memory gate electrode 11 . The polysilicon film is etched back by performing anisotropic etching and, a side wall electrode is formed just on the side of the gate electrode serving as the step section in FIG. 19 . This side wall electrode is formed by anisotropic etching so that a memory gate electrode with a gate length of approximately 60 nanometers can be formed and with only a slight amount etched away to the side.
[0090] Here, the gap between the side surface of the contact auxiliary pattern 22 and the side surface of the gate electrode 12 in the contact section is kept within a fixed distance so that there is no separation of the polysilicon film doped with impurities formed between the contact auxiliary pattern 22 and the selection gate electrode 12 . In the present embodiment, that fixed distance is equivalent to 188 nanometer which is double that sum of the 19 nanometer thick ONO film and the 75 nanometer thick polysilicon film. At the stage in FIG. 18 , if the gate electrode 12 and contact auxiliary pattern 22 are formed at least within a distance of double the sum of the ONO film deposit thickness and the gate polysilicon film thickness of the sidewall electrode gate, then a structure with mutually connected side wall gates can be easily achieved.
[0091] In the method of the related art, the photo-resist is coated on after forming (depositing) a polysilicon film doped with impurities so that anisotropic etching was performed after patterning with photo-resist by utilizing a dedicated lithographic mask, in order to leave a polysilicon film on the section where the contact was formed. In the present embodiment however, an auxiliary pattern can be formed with the mask used for the selection gate electrode so that no additional mask is used for forming the contact region.
[0092] Next as shown in FIG. 21 , an unneeded side of the side wall electrode 40 among the side wall electrodes that were formed, and the side wall electrodes 41 on both sides of the logic area are stripped away by etching using photolithography or dry etching, and the underlayer of the ONO film whose polysilicon was removed is also stripped away in the same way. The method for stripping away the film is not limited to dry etching and even wet etching may be utilized. However, the silicon nitride film and the silicon oxide film possess a high etching rate so that an etching gas or etchant that matches each film must be separately used as needed. At this point in time, the gate electrode is masked and the semiconductor region forming the source and drain of the transistor is formed by ion implantation. Here, in a process subsequent to forming the upper surface of gate electrode 12 , the ONO film on the upper surface of gate electrode 12 is stripped away in order to simultaneously silicide the memory gate electrode 11 . The ONO film formed on the upper surface of the auxiliary pattern 22 is simultaneously stripped away at this time.
[0093] As shown in FIG. 22 , from here, the SiO 2 film forming the side wall of the gate electrode of the logic area transistor and the gate electrode for the memory area transistor are deposited, and etched back by anisotropic etching.
[0094] As shown in FIG. 23 , siliciding of the substrate surface of the semiconductor region functioning as the source and drain of the memory cell, and the gate electrode of the memory transistor, and gate electrode of the selection transistor for the memory area is performed, to form a silicide layer 27 . The silicidation is performed to lower the resistance of the semiconductor region and gate electrode, and for example is performed by depositing a metal layer such as cobalt by sputtering and then annealing (that layer). The metal for the silicidation is not limited to cobalt and other metals such as nickel may be utilized.
[0095] In this process, silicidation of the substrate surface of the semiconductor region functioning as the source and drain and the gate electrode of the transistor logic area is also performed simultaneously. Metal that did not react with the gate electrode and substrate by the silicidation anneal is also removed.
[0096] Afterwards, as shown in FIG. 24 , a first layer of insulator film 42 is deposited (or formed), planarized by CMP (chemical mechanical polishing), and the contact areas are formed. The contact 21 of the memory transistor gate electrode is formed on the external circumferential section of the auxiliary pattern 22 sufficiently separated from the selection gate electrode 12 . Therefore, exposure of the gate electrode 12 of the selection transistor can be prevented even if the contact hole mask position alignment for example has deviated, and electrical shorts between the gate electrode of the memory gate and the gate electrode of the selection transistor can be prevented. The size of the normal contact hole is larger than the width of the side wall electrode formed on the external circumference of the auxiliary pattern so that forming the contact hole serves to expose the surface of the side wall electrode and the upper surface of the auxiliary pattern whose ONO film was removed, and a contact 21 is formed in that contact hole.
[0097] Contact holes for a contact 61 and a contact hole 42 are formed during forming of the contact hole for the contact 21 , and their respective contacts are formed by the same process. After this (process), a metal wiring process is performed to form a standard three to six layers however a description is omitted here.
[0098] The detailed process flow of the stages of the process for forming the contact are shown in FIG. 26 through FIG. 29 . These stages are expressed by the cross section B-B′ in FIG. 17 . The memory gate electrode at 60 nanometers is tiny and therefore possesses a high resistance. In order to achieve high-speed operation silicidation of the memory gate electrode must be performed to lower resistance in order to prevent a voltage drop along the word line. Silicidation is also required for the selection gate electrode and of both electrodes must be performed by the following procedure.
[0099] The stage for forming a SiO 2 spacer on the memory gate electrode side wall is shown in FIG. 26 . Then, after ion implantation and activation anneal to the diffusion area of the logic area and memory area and activation anneal, the silicide metal film 43 is deposited by sputtering as shown in FIG. 27 . Here, cobalt was utilized as the metal for silicidation.
[0100] Then, after the silicidation anneal, the non-reacting cobalt is removed by wet etching and after once again performing activation annealing, a silicide layer 27 is formed as shown in FIG. 28 .
[0101] By forming a silicide layer 27 where the cobalt reacts only with silicon, the silicide layer 27 is formed by self-alignment only above the upper section of the selection gate electrodes 12 , contact auxiliary pattern 22 , and memory gate electrode wiring layer 23 , 24 , without forming silicide on the ONO film upper section 44 .
[0102] After simultaneously siliciding each electrode, an interlayer insulator film 42 is deposited, and after removing the step by the CMP, the contact hole is formed, and the contact 21 then formed at the stage in FIG. 29 . The contact 21 is formed on the side wall electrode 24 formed on the external circumference of the contact auxiliary pattern 22 at a sufficiently separated position in order to take alignment mismatch on deviations from the selection gate 12 into account. While the selection gate electrode is tiny at a width of 60 nanometers, the contact diameter is large at 250 nanometers so that the contact 21 makes contact not only with the memory gate electrode wiring section 24 , but also with the contact auxiliary pattern 22 and the device isolator 25 . The contact auxiliary pattern 22 is electrically isolated, and there will be no problem even if an electrical short occurs between the contact auxiliary pattern and the contact or memory gate. An example where the device isolator 25 is also etched during forming of the contact hole is shown in FIG. 29 . However even if a section of the device isolator 25 is etched along its depth, and a contact formed in that section, the device isolator 25 is a field isolating insulator film so there will be no (shorting) problem.
[0103] A condition for forming this shape is that the gap x between the side surface of the contact auxiliary pattern 22 and the selection gate electrode 12 must be x<2×(t+d) where d is the polysilicon deposition thickness of the selection gate electrode and t is the ONO film thickness. This relation is shown in the graph in FIG. 30 .
[0104] The gap x between the side surface of the contact auxiliary pattern 22 and the selection gate electrode 12 shown on the horizontal axis, and polysilicon film deposit thickness d is shown along the vertical axis. The ONO film thickness t must be a specified thickness or more in order to suppress leakage of stored electrical charges in the ONO film thickness t, and is assumed to be a fixed value of 20 nanometers since this value does not change according to scaling.
[0105] A region 50 capable of filling the gap between the contact auxiliary pattern and the selection gate is shown by the oblique line in the graph. The example in this embodiment utilizes a process for the 0.18 micrometer rule. The polysilicon depth d is 75 nanometers, and at 2×(t+d) equals 190 nanometers. Polysilicon can be filled into formed even smaller than this value. The extension line 51 is shown as a prediction for next generation scaling however the margin can be expanded even further to allow for a generation to 90 nanometers.
[0106] In order to reliably ensure the required described conditions, in view of future gate lengths for memory gate electrodes, the gap between the side surface of the auxiliary pattern 22 and the side surface of the selection gate 12 may be formed so as to be within double the sum of the ONO film thickness and the memory gate electrode gate length.
[0107] An important factor not related in detail up until now regarding the forming position of the contact 21 is that as shown in FIG. 17 and FIG. 31 , the contact 21 is preferably formed in the direction the selection gate electrode 12 extends versus the auxiliary pattern 22 . Forming the contact 21 in this position prevents the contact 21 from electrically shorting to the selection gate electrodes. In other words, forming the contact 21 in a region between the selection gate electrode 12 and the auxiliary pattern 22 , when a deviation in the alignment of the contact hole mask has occurred during forming of the contact holes for the memory gate electrode, will expose the surface of the selection gate, and then forming the contact will cause an electrical short between the selection gate electrode 12 and the contact for the memory gate electrode power supply.
[0108] Electrical shorts between memory gate electrodes can also be prevented by forming the contact as described above. In other words, when attempting to form the contact in a region between the auxiliary pattern 22 (auxiliary pattern 22 on left side of FIG. 17 ) and the adjoining memory gate electrode 11 (memory gate electrode 11 on right side of FIG. 17 ), and a deviation in position alignment of the contact hole forming mask has occurred, then when forming the contact holes for the memory gate electrode on the left side of FIG. 17 , the surface of the memory gate electrode (memory gate electrode 11 on the right side of FIG. 17 ) is exposed, and the surfaces of the memory gate electrodes 11 on both left and right of one contact hole in FIG. 17 are exposed, so that forming the contact causes the memory gate electrode 11 and the contact to short and the memory gate electrodes short with each other. A layout is therefore required that takes into account deviations in the mask position between the auxiliary pattern 22 (auxiliary pattern 22 on left side of FIG. 17 ) and the adjoining memory gate 11 (memory gate electrode 11 on right side of FIG. 17 ), and the width of the auxiliary pattern 22 (auxiliary pattern 22 on left side of FIG. 17 ) and the selection gate electrode 12 (selection gate electrode on right side of FIG. 17 ) must be widened.
[0109] The contacts 21 are therefore preferably formed in the direction the selection gate electrode extends versus the auxiliary pattern 22 . More specifically, the contacts 21 are formed on the corners perpendicular to the direction that the selection gate electrode for auxiliary pattern 22 extends. Forming the contacts 21 in this way reduces the possibility of electrical shorts and eliminates the need to widen the width between the selection gates 12 .
[0110] Even more preferable as shown in FIG. 17 and FIG. 31 , is forming the contacts 21 between the pair of side wall electrodes formed on the corner sides along the direction the selection gate electrode extends among the four sides of the auxiliary pattern 22 . By forming the contact 21 (contact 21 on left side of FIG. 17 ) in this way, there is no contact with the adjoining memory gate electrodes 11 (memory gate 11 on right side of FIG. 17 ), and the contact 21 does not make contact with the selection gate electrode 12 (selection gate 12 on left side of FIG. 17 ). The contact 21 also does not protrude outward from the side wall electrodes formed on the periphery of the auxiliary pattern 22 (auxiliary pattern 22 on left side of FIG. 17 ) in a direction perpendicular to the direction the selection gate electrodes extend, so that the memory gate electrodes 11 (memory gate electrode 11 on right side of FIG. 17 ) and the side wall electrode formed on the periphery of the auxiliary pattern 22 can be formed together up to a minimum dimension within a range where they do not make contact. Therefore, when the size of the auxiliary patterns 22 are the same, the pitch width between the selection gates can be reduced, and the memory array can be more highly integrated.
[0111] The electrode that must utilize the contact 21 relative to the direction the selection gate electrode extends is the side wall electrode. However, the width of the sidewall electrode is formed by self-alignment and so is narrower than the width of the contact 21 . Therefore, the side wall electrode is formed mainly in the center of the contact. Consequently, the contact must be formed at a position to make contact with the auxiliary pattern 22 , and further must make contact with the field isolating insulator (film).
[0112] The invention of these specifications is therefore capable of simplifying the process for manufacturing nonvolatile memories for high-speed operation and possessing a split-gate structure.
[0113] The invention of these specifications is also capable of reducing the pitch width between the selection gates and making the memory array more highly integrated.
Second Embodiment
[0114] As an adaptation of the first embodiment, the second embodiment is described using an example for connecting the side wall electrode to another word line. A flat view of the layout of the contact region of the second embodiment is shown in FIG. 32 .
[0115] As shown in FIG. 32 , the selection gate electrode within the first memory array region E and the second memory array region F are physically separated on the field isolating insulator (film) and an auxiliary pattern 2 is formed in between them. The respective memory gate electrodes are connected to the side wall electrodes formed on the periphery of the auxiliary pattern, and by forming a contact over those side wall gate electrodes, power can be supplied from the contact to the memory gate electrode within the first memory array region and the memory gate electrode within the second memory array region. Utilizing this type of structure eliminates the need to form an auxiliary pattern between the adjacent selection gates. The pitch between the adjacent selection gate electrodes, namely (the pitch) between the word lines can be narrowed, and the region E and the memory array within F can be made more highly integrated, perpendicular to the direction that the selection gate electrode extends.
[0116] The manufacturing method for the second embodiment of this invention is described next. The manufacturing method of the second embodiment is identical to the first embodiment in FIG. 18 through FIG. 24 . The point where the second embodiment differs is the positional relationship between the selection gate electrode and the auxiliary pattern in the flat layout. As shown in FIG. 32 , the selection gate electrodes are physically separated on the field isolating insulator (film) and, an auxiliary pattern is formed between those separated selection gates. Here, the important point is the distance between the side surface of the auxiliary gate pattern and the side surfaces of the respective gate electrodes. The respective gate electrodes are formed at a position closer than a distance of twice the sum of the film thickness of the gate electrode material for the memory gate formed by self alignment, and the film thickness of the ONO film formed later within that distance (between gate pattern and gate electrodes). Forming the gate electrodes at this position allows forming the self-aligned memory gate electrodes, relative to the memory cells within the region D and E, however memory gate electrode material that is not physically separated still remains between each selection gate electrode and the auxiliary pattern on the field isolating insulator (film). Consequently, forming a contact on the side wall electrode formed on the periphery of the auxiliary pattern, allows supplying power to the memory gate electrodes via the side wall electrodes.
[0117] The placement of the contact is described here. The direction the selection gate electrode 12 extends and its perpendicular direction, and the placement of the contact are reversed from the positional relation in the first embodiment. In other words, in the second embodiment, the auxiliary pattern is enclosed from above and below by the selection gate electrodes 12 so that when the contacts are formed on the side perpendicular to the direction that the selection gate electrode extends among the four side of auxiliary pattern 22 , then a short might possibly in the upper and lower selection gate electrodes of the auxiliary pattern 22 on FIG. 32 due to a deviation in the mask position alignment. The contact is therefore preferably not formed to overlap on the sides perpendicular to the direction the selection gate electrode of the auxiliary pattern extends. However the contacts are preferably formed in a region between the pair of side wall electrodes formed on the sides in a perpendicular direction. Moreover, even if a deviation in position alignment of the contact 21 occurs perpendicular to the direction that the selection gate electrode extends, the side wall electrode and the contact are placed correctly so that the contact is positioned to make contact with the auxiliary pattern 22 and the field isolating insulator film.
[0118] The forming of the contact in the memory array was described in the present embodiment. However the pitch between the selection gate electrodes can be reduced by forming an auxiliary pattern along the selection gate electrode extension for the contact at the tip of the memory gate electrode of the memory array.
[0119] The present embodiment contains a silicidation process of the gate electrode as in the first embodiment; however, he silicidation process is not an indispensable process in terms of making the memory array more highly integrated. However, silicidation of the gate electrode can prevent higher resistance in the gate electrode that occurs when the gate electrode is reduced to a tinier size, and a nonvolatile memory capable of high-speed operation can be fabricated.
[0120] In this type of embodiment, the contact region for the memory gates can be separated from the selection gate electrodes so that for example even if a deviation in mask position alignment occurs, a memory gate contact can be formed without electrical shorts occurring between the memory gate electrode and the selection gate electrode.
[0121] A dedicated mask is not required for forming the auxiliary pattern so the number of masks can be reduced and the manufacturing cost can also be drastically reduced. There are also fewer processes so that a high-performance nonvolatile memory can be easily fabricated.
[0122] There is also no need to form a contact region between adjacent word lines so the word line pitch can be further narrowed, and higher integration can be easily achieved.
Third Embodiment
[0123] This embodiment is a variation on the first and second embodiments, in which the side wall electrodes are connected to other word lines. A flat layout of the contact region of the third embodiment is shown in FIG. 38 .
[0124] As shown in FIG. 38 , an auxiliary pattern is formed between the adjoining selection gate electrodes. Up to here it is identical to the first embodiment however the unique feature of this embodiment is that the opposing adjacent memory electrodes are connected by one auxiliary pattern. In other words, the adjacent memory gate electrodes are connected with side wall electrodes formed on the periphery of the auxiliary pattern, and power can be supplied from the contact to the respective memory gate electrodes, by forming contacts on these side wall gate electrodes. Utilizing this type of structure allows further narrowing the distance between the adjacent memory gate electrodes. Therefore the pitch between the selection gate electrodes, or in other words, (the pitch) between the word lines can be narrowed, and the memory array within the regions E and F can be highly integrated, perpendicular to the direction the selection gate electrode extends. Moreover, one contact can be formed for the adjacent memory gate electrodes so that the number of contacts can be reduced. Forming of the wiring (layers) on the upper layers is made simpler since there are fewer contacts.
[0125] The manufacturing method for the third embodiment of this invention is described next. The manufacturing method is the same as in FIG. 18 through FIG. 24 in the first embodiment. The point where the present embodiment differs is the positional relation of the selection gate electrode and auxiliary pattern in the flat layout. As shown in FIG. 38 , an auxiliary pattern is formed between the adjacent selection gate electrodes. Here, the important point is that the distance between the side surface of the auxiliary gate pattern and the side surfaces of the respective gate electrodes. The gate electrodes are respectively formed at a position closer than a distance of twice the sum of the film thickness of the gate electrode material of the memory gates formed by self alignment, and the film thickness of the ONO film formed later within that distance. Forming the gate electrodes at this position allows forming the self-aligned memory gate electrodes, relative to the memory cells within the region D and E, however memory gate electrode material that is not physically separated still remains between each selection gate electrode and the auxiliary pattern on the field isolating insulator (film). Consequently, forming a contact on the side wall electrode formed on the periphery of the auxiliary pattern, allows supplying power to the memory gate electrodes via the side wall electrodes.
[0126] The placement of the contacts is identical to the first embodiment so a description is omitted here.
[0127] The present embodiment contains a process for siliciding the gate electrode as in the first embodiment, the siliciding process is not however an indispensable process in terms of making the memory array more highly integrated. However, siliciding the gate electrode can prevent higher resistance in the gate electrode that occurs when the gate electrode is reduced to a tinier size, and a nonvolatile memory capable of high-speed operation can be fabricated.
[0128] In the present embodiment, the adjacent gate electrodes are electrically connected so that the voltages across adjacent gate electrodes cannot be separately controlled. However the nonvolatile memory in the present embodiment is the type that holds the electrical charge by means of a charge trapping film so that unlike the floating gate type of nonvolatile memory, there will be no problem even if the memory gate electrodes are mutually connected electrically. Also, in the nonvolatile memory in the present embodiment, the electrically connected gate electrodes are memory gates and therefore the selection gate electrodes can be separately controlled so that the respective memory cells can be selected by controlling the selection transistor so that the writing on a desired memory cell can be performed.
[0129] Utilizing this type of embodiment allows separating the memory gate contact region from the selection gate electrodes so that for example, even if a deviation in the mask position alignment occurs, the memory gate contacts can be formed and there will be no electrical shorts between the memory gate electrodes and the selection gate electrodes.
[0130] A dedicated mask is not required for forming the contact regions so the number of masks can be reduced and the manufacturing cost can also be drastically reduced. There are also fewer processes so that a high-performance nonvolatile memory can be easily fabricated.
[0131] In the first embodiment, there was one auxiliary pattern for one memory gate electrode, so that among opposing memory gate electrodes, the selection gate electrode and the auxiliary pattern of the memory gate electrode not requiring power, had to be separated by a fixed distance. However in the present embodiment, there is no need to separate them (selection gate electrode and auxiliary pattern) by a fixed distance so the word line pitch can be narrowed, and higher integration can be easily achieved.
[0132] Moreover, one contact can be formed for the adjacent memory gate electrodes so that the number of contacts can be reduced. Forming of the wiring (layers) on the upper layers is therefore made simpler since there are fewer contacts.
Fourth Embodiment
[0133] The fourth embodiment utilizes an example where multiple auxiliary patterns are formed. In the present embodiment, the case where applied to the first embodiment is described.
[0134] The flat layout of the fourth embodiment is shown in FIG. 39 . In the example in this figure, two auxiliary patterns are formed for one selection gate electrode. Here, memory gate electrode material is formed in the auxiliary pattern, the same as the memory gate electrode material formed between the auxiliary pattern and the selection gate electrode. The unique feature of this embodiment is that a contact for the memory gate electrode is formed in the auxiliary pattern, and that the contact is formed over the side wall electrode and the auxiliary gate electrode.
[0135] The manufacturing method of this embodiment is described next. In this embodiment, the auxiliary patterns may be respectively positioned so that the distance to the side surface of the selection gate electrode, and the respective side surfaces of two auxiliary patterns, are at a position closer than double the sum of thickness of the ONO film formed later (after the side surfaces) and the film thickness of the gate electrode material of the memory gate formed by self-alignment.
[0136] In the present embodiment, during forming of the contact holes after the forming of the interlayer dielectric (insulator) film, only the side wall gate electrode and the auxiliary gate electrodes can be exposed without exposing the field isolating insulator film so that defects due to forming the contact on the field isolating insulator (film) can be prevented without etching the field isolating insulator film during etching of the contact holes. Defects that occur in particular due to penetrating of the field isolating insulator (film) and making an electrical connection with the semiconductor substrate can be avoided.
[0137] In the present embodiment, two auxiliary patterns were positioned at respective desired distance from the selection gate electrodes. However, one of the auxiliary patterns (first auxiliary pattern) may be formed at a desired distance from the selection gate, and the other auxiliary pattern (second auxiliary pattern) may be formed at a desired distance only relative to the auxiliary pattern (first auxiliary pattern). However, when positioned in this way, the width between the adjacent word lines must be widened so that when forming multiple auxiliary patterns in this embodiment, each of them must be formed at the respective desired distance from the selection gate electrode.
[0138] In the present embodiment, the forming of two auxiliary patterns was described however two or more auxiliary patterns may be formed for one gate electrode.
[0139] In the present embodiment, besides the effect described in the first embodiment, defects can be avoided by etching the field isolating insulator film, and forming a contact in that field isolating insulator film.
[0140] Though this embodiment was described with an example for the first embodiment, the present embodiment is also applicable to the second and third embodiments. Besides the effects described in the second and third embodiments, defects due to etching the field isolating insulating film and forming the contact in that film can be prevented.
Fifth Embodiment
[0141] The example in the fifth embodiment applies the SAC (Self Aligned Contact) to the contact. The memory cell and array structure, and contact section surface layout are the same as the first embodiment. The process flow of the contact forming stage is shown in FIG. 33 through FIG. 37 .
[0142] FIG. 33 through FIG. 37 are views taken along lines B-B′ of FIG. 17 .
[0143] FIG. 33 shows the stage where the selection gate electrode and the memory gate electrode upper section are silicided by the method of the first embodiment. The etching stopper shown here is a state in FIG. 34 where a SiN film 28 was deposited to 50 nanometers by the CVD method. After depositing SiO 2 film to 1200 nanometers as the first layer of the insulator film 42 , the roughness (concavities, protrusions) on the surface are planarized by the CMP at the stage shown in FIG. 35 .
[0144] The contact hole 62 is formed by photolithography and dry etching. The dry etching is performed in the following multiple stages. First of all, after etching the BARC layer (anti-reflective layer) to improve the resolution, the SiO 2 is etched under conditions where the SiO 2 possesses a higher selectivity rate than SiN. In this way, the SiN layer 28 functions as a stopper, and even if there is a gate electrode step as shown in FIG. 36 , the etching essentially stops at the point in time that the SiN is exposed so that no over-etching occurs.
[0145] Next, when etching is performed under conditions where the SiN etching selection rate is higher than the SiO 2 , then only the SiN is exposed to attain the state in FIG. 37 . The SiO 2 is difficult to etch so that even when the contact deviates from the mesh and reaches the field isolating insulator region (device isolation region) as shown in FIG. 29 , there is no excessive removal of SiO 2 . Therefore, in this invention there is no excessive etching of the field isolating insulator film when forming the contact holes 62 so that defects can be avoided by forming the contact within the etched section. | Semiconductor device and manufacturing method for reducing the number of required lithography masks added to the nonvolatile memory in the standard CMOS process to shorten the production period and reduce costs. In a split-gate memory cell with silicided gate electrodes utilizing a sidewall structure, a separate auxiliary pattern is formed adjoining the selected gate electrodes. A contact is set on a wiring layer self-aligned by filling side-wall gates of polysilicon in the gap between the electrodes and auxiliary pattern. The contact may overlap onto the auxiliary pattern and device isolation region, in an optimal design considering the size of the occupied surface area. If the distance to the selected gate electrode is x, the ONO film deposit thickness is t, and the polysilicon film deposit thickness is d, then the auxiliary pattern may be separated just by a distance x such that x<2×(t+d). | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to imaging. More specifically, the invention relates to detecting defective pixels in an image sensor.
2. Description of the Related Art
Imaging devices such as digital cameras and scanners may have as one component, an image sensor which is manufactured as a CCD (Charge Coupled Device), CID (Charge Injection Device) or CMOS (Complementary Metal-Oxide Semiconductor) device. The image sensor is composed of an array of “sense” or pixel locations which captures energy from a illuminant, often converting this energy into a concrete measure such as an intensity value. In most cases, imaging sensors will have a certain number of pixel locations which are “defective” due to fabrication or manufacturing errors. It is extremely difficult, if not impossible, to guarantee during such fabrication/manufacturing that none of the pixels in the sensor will be defective. A “defective” pixel of a sensor is one which when exposed to an illuminant will produce a different intensity value or response than that of a “fully functional” pixel when exposed to that same illuminant. In other words, the defective pixel is abnormally sensitive/unsensitive to light than a fully functional pixel. Such defects if not detected and then compensated for, may cause the captured image to be of less visually perceived quality and if prominent can detract the attention of the viewer towards the defective pixel(s).
Defects in pixel locations can be split into three categories-Stuck High, Stuck Low and Abnormal Response. A Stuck High defective pixel is one which always responds to the lighting condition by producing a high intensity value. For instance, if the intensity of pixels ranges from 0 to a high of 255, a Stuck High pixel would always respond to lighting with a value of 255, even if actual measured intensity for that location of the scene would be 25, for example, if captured by a functional pixel. A Stuck Low defective pixel is one which always responds to the lighting condition by producing a low intensity value. A Stuck Low pixel may respond with a value of 5 even though a functional pixel would show the intensity value to be 200, 100 etc. A pixel with an Abnormal Response defect has no absolute, but rather a relative variance from a functional pixel. For instance such a pixel would inaccurately respond by a particular percentage, such that, for instance, were a functional pixel would read a value X, the Abnormal Response defective pixel would respond with a value 0.25*X. The Abnormal Response is thus proportional or relative to the intensity being captured, rather than an absolute high or low. Pixels exhibiting any of these types of defects should, desirably, be corrected or compensated for.
The first step in any such compensation is the detection of which pixels are in fact “defective”. Conventionally, such detection is performed by identifying the defective pixel locations in a controlled environment, such as during quality control for the sensor as a whole, after the sensor is fabricated. The identified locations are recorded and then transferred to some non-volatile memory on the device in which the sensor is used such as on a digital camera. In modern “mega-pixel” image sensors, where the total size of the sensors have on the order of 1000 by 1000 pixels, many pixels may be defective. The extra memory needed to store the defective pixel locations adds to the total cost/time-to-manufacture of the device and also requires actual data transfer during the process of assembling/integrating the sensor into the device. The defective pixel locations must be separately stored prior to device assembly into a fixed memory such as a hard disk. Once the defective locations are stored, signal processing techniques post image capture may be used to correct the defective pixels. A more arbitrary way of correction image defects, which has also been utilized, is to not detect defective pixels, but treat the unknown defects as noise and apply an image-by-image noise removal technique to the entire sensor output (image). While avoiding memory cost and data transfer during assembly, such techniques have the disadvantage of being computationally expensive to implement and of potentially reducing the sharpness of the image, which is a key to visual appearance.
For these reasons, there is a need for a method to detect and compensate for defective pixel locations without adding to the time/cost of manufacture of the device and without sacrificing image quality or adding to the computation requirements during image processing on the device in which the sensor is to be employed.
SUMMARY
What is disclosed is a method comprising performing an observation on a sensor having a plurality of pixels, for each of the pixels that are unclassified, determining a score according to the observation, if the score for the each pixel satisfies a stopping condition, classifying the each pixel as being one of either defective or functional, and repeating the steps of performing, determining and classifying for any the pixels remaining unclassified after determining the score.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects, features and advantages of the method and apparatus for the present invention will be apparent from the following description in which:
FIG. 1 is a flow diagram of an embodiment of the invention.
FIG. 2 shows the determining of an MND (Minimum Neighboring Distance) according to an embodiment of the invention.
FIG. 3 shows an exemplary probability distribution of MND values for one image.
FIG. 4 is a representation of the number of observations (i.e., scanned images) needed for an accurate determination of classification of a pixel.
FIG. 5 ( a ) illustrates a weighting function for a Stuck Low defect.
FIG. 5 ( b ) illustrates a weighting function for a Stuck High defect.
FIG. 6 is a block diagram of an image processing apparatus according to an embodiment of the invention.
FIG. 7 is a system diagram of one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the figures, exemplary embodiments of the invention will now be described. The exemplary embodiments are provided to illustrate aspects of the invention and should not be construed as limiting the scope of the invention. The exemplary embodiments are primarily described with reference to block diagrams or flowcharts. As to the flowcharts, each block within the flowcharts represents both a method step and an apparatus element for performing the method step. Depending upon the implementation, the corresponding apparatus element may be configured in hardware, software, firmware or combinations thereof.
FIG. 1 is a flow diagram of an embodiment of the invention.
In statistical analysis, an approach known as the Sequential Probability Ratio Test (SPRT), set forth in “Sequential Analysis”, A. Wald (Wiley & Sons, New York 1947), has been developed. In the SPRT approach, an inference is made which attempts to identify one of two hypotheses from a sequence of observations. For instance, in the defective pixel detection case, the hypotheses may be the presence of a defective pixel and the presence of a functional pixel. When an adequate number of observations are made, a decision may be arrived at as to which of the two hypotheses fit. This decision may or may not be accurate since it is based upon a statistical approximation. The goal then in such approaches is to reduce the impact of false detections upon the decision space. Such approaches also work best when the content of the observed samples is known a priori. The software approach to defective pixel detection, in one embodiment, may impose on the end user the task of initiating the detection/correction process. Since the content of images to be scanned in during this detection process is unknown, the SPRT must be made robust such that it dynamically changes according to measured observations.
With this framework in mind, FIG. 1 illustrates a logic flow that can achieve defective pixel detection. Initially it is assumed that all the pixel locations are unknown or indeterminant (i.e., classified neither defective nor functional). Accordingly, the condition at step 100 would be satisfied. When some pixels remain unclassified, the first step in SPRT classification is to scan in an image using a device that is already constructed with and incorporates the sensor array under consideration (step 110 ). Each scanned image would represent a new observation upon which measurements may be made. After an image is captured into the sensor array, the image is scanned for information content which can be measured (step 120 ) such as a readout of the intensity value for each pixel. According to one embodiment of the invention, a measurement is performed by considering the minimum neighboring distance (MND) of surrounding pixels (see FIG. 2) whether the neighborhood is composed of all monochrome pixels or only those in a particular color plane of a Bayer Pattern CFA (Color Filter Array). Next, the image statistics, primarily, the mean, variance and/or standard deviation, of the values are measured (step 130 ) from the MND. For all unclassified pixel locations (checked at step 135 ), a “score” is then determined (step 140 ) location by location. The score is based upon the estimated likelihood of a pixel being defective. If this score satisfies a particular stopping condition (checked at step 150 ), then the pixel under consideration may be classified accordingly as either being defective or functional (step 160 ) and further may have a designation as to the type of defect. If not, then another unclassified pixel is processed (repeat from step 135 ). Advantageously, when a pixel is capable of being classified, the defective pixel locations may all be stored into host computer or external device (step 170 ) so that corrective measures such as noise reduction may be undertaken on only those pixel locations judged to be defective. This also eliminates the need for storing defective pixel location data on the sensor device, camera and also the need for determining it during manufacture. Further, only defective location need be stored (step 170 ) with the default that all other locations are functional.
Once all unclassified pixels in given observation (scanned image) are processed (checked at step 135 ) then the procedure returns to step 100 . Again, at step 100 , if unclassified pixels still remain even after processing of pixels using the last scanned image, the next image is canned in (step 110 ) and steps 120 - 170 are repeated. Each scanned image represents a statistically relevant observation, and on each observation, only those pixels whose scores did not satisfy a stopping condition are reprocessed. This continues until all (or most depending on desired design) pixel locations are classified.
FIG. 2 shows the determining of an MND (Minimum Neighboring Distance) according to an embodiment of the invention.
A minimum neighboring distance (MND) for a given pixel X 5 may be determined by considering the “distance” or differential between neighboring pixel values and that given value. FIG. 2 shows a neighborhood of eight adjacent pixels X 1 , X 2 , X 3 , X 4 , X 6 , X 7 , X 8 and X 9 about a pixel X 5 . For a monochrom sensor, or desired output, the distance (i.e., the absolute value difference) between each of those neighbors and the central pixel X 5 is computed. The minimum of these distances becomes the MND for that pixel X 5 . Alternatively, a neighborhood consisting of only north, south, east and west neighbors, X 2 , X 8 , X 6 and X 4 , respectively, may be considered in determining the MND. In a Bayer pattern sensor, it may be desirable to consider only those neighboring pixel, in the same color plane (R, G or B). In a sensor array that has a captured intensity value at each location, it is likely that closely neighboring pixels should have the same or similar intensity values with those of their neighbors. This assumes that the neighboring pixels contain no defects (see FIG. 3 and associated description for description of defects). This is especially true with large sensors or a small field of view during image capture or both. The MND, also denoted as Y, tells roughly how close to neighboring pixels a certain pixels response is. For example, Y may be given as Y=min(|X 5 -X k |) k ∈ {1,2,3,4,6,7,8,9} for a monochrom sensor, or Y=min(|X 5 -X k |) k ∈ {1,3,7,9} for a Bayer pattern sensor with X 5 as a Green pixel. For instance, consider the following intensity values X 1 =100, X 2 =90, X 3 =95, X 4 =105, X 6 =110, X 7 =85, X 8 =80 and X 9 =75. If X 5 , the pixel under consideration, has an intensity value of 102, the minimum neighboring distance would be (102-100)=2, and in reference to FIG. 3, the value of “b”, the intensity value of the pixel location (X 1 ) yielding the MND would be 100.
FIG. 3 shows an exemplary probability distribution of MND values for one image. Functional pixels will most likely, in a statistical sense, not deviate far from a neighboring pixel and will probably have the same response. Thus, where the MND is zero, for instance, the pixel under consideration can with a high (perhaps the highest) degree of certainty be classified as functional. Thus, the distribution of Y, which is plotted in FIG. 3 is equal to P 0 (y) when the functionality of the pixel is most likely to be guaranteed. The distribution of Y, the MNDs, for functional pixels has been found on experimentation to resemble the well-known Gamma distribution. Based on image statistics, likewise, a gamma distribution curve of the defective pixel classification hypothesis may be derived. The center and exact parameters of the gamma distribution will vary depending upon which type of defect is under concern. If “b” is the intensity value of that neighboring pixel which yielded the MND, then the center C of a distribution for a defect can be modeled by:
Stuck High - - - C ˜˜| 1255- b|
Stuck Low - - - C ˜˜|b |, and
Abnormal Response - - - C ˜˜ 0.15 *b.
The abnormal response defect is assigned an exemplary 15% deviation but may be any value as desired or as motivated by sensor properties or design constraints. In a highly spatially correlated image, a functional pixel will have its MND distribution centered about zero or close to zero and will rapidly diminish with increasing values. The values given above assume an eight bit (ranging from 0 to 255) intensity value at each pixel location. For a stuck high defect, the value C is very close to 255, while for a stuck low, the center of the distribution is approximately b according to the definition of the MND. An abnormal response is a pixel that while not stuck high or stuck low, may be out of an acceptable tolerance. P 1 (y) is the probability of the hypothesis of defect being true while P 0 (y) is the probability of the other hypothesis that of a functional pixel being true. If the distributions as shown in FIG. 3 overlap, any MNDs therein are very uncertain and should contribute little, if at all, to the overall score. The generalized gamma distribution, which the MNDs of functional pixels approximately follow, may be represented as: P 0 ( y ) = 1 C ∫ y y + 1 λ α x α - 1 - λ x Γ ( α ) x for y = 0 , 1 … L
where 0<α≦1, y is the MND, Γ(α) is the Euler's gamma function, L the maximum possible MND, and “c”, is a scaling factor. The α and λ are computed as α=m 2 /σ 2 and λ=m/σ 2 , where m is the mean of the measured MNDS, and σ 2 the variance.
FIG. 4 is a representation of the number of observations (i.e., scanned images) needed for an accurate determination of classification of a pixel. According to SPRT theory, there is in a binary hypothesis scheme, a likelihood ratio that can be measured. The likelihood ratio is P 1 (y)/P 0 (y) or the probability of the observed pixel having condition 1 (defective) divided by the probability of the observed pixel having condition 0 (functional). This likelihood ratio is a representation of the level of uncertainty regarding the measurements (MNDS) performed for a given pixel. Where the results are uncertain, more data (observations) in the way of more scanned in images may be needed. At each image scan and analysis, the likelihood ratio is multiplied together with past likelihood ratios, since each observation is an independent probabilistic event. This “accumulated” likelihood ratio is the “score” used to determine whether or not a pixel can be properly classified as defective or functional. If the logarithm of the accumulated likelihood ratio is considered, then the individual likelihood ratio at each observation may be added with previous likelihood ratios to determine and keep track of the score.
FIG. 4 shows a graph of the log of the likelihood ratio versus the number of desired observations. Two (or more) boundary or stopping conditions may be defined for the sensor array, a condition A wherein the pixel can be likely accurately classified as functional and a condition B wherein the pixel upon reaching that boundary, the pixel may likely be classified accurately as defective. Assuming a sequence of observations y 1 , y 2 . . . yn are needed for a given pixel, the log of the likelihood ratio (i.e., log (P 1 (y)/P 0 (y))) may increase or decrease until it satisfies one of the two stopping conditions A and B. When no images (n=0) have yet been captured, the likelihood ratio is one, therefore the log is zero since it is equally probable that the given pixel is defective as it is functional without any prior observations or knowledge regarding the sensor. As each observation is made, the uncertainty diminishes. The likelihood ratio is greater than one when the pixel under consideration is more likely to be defective (i.e., P 1 (y)>P 0 (y)), and less than one when the pixel under consideration is more likely to be functional (i.e., P 1 (y)<P 0 (y)). The number of observations required for each pixel location depends upon the reliability or characteristics of neighboring pixels and thus may vary from image region to image region. In one region, it may be possible to reach a stopping condition with very few observations and in another, with more observations. The number of observations needed depends upon the image content and the type of defective pixel desired to be detected. Not all images that observed are equal in response. Where non-functional (i.e. defective) pixels are concerned, the center or peak location of the distribution of the MNDs may be more dependent upon the local neighboring pixel intensities. If a user is performing the pixel detection, the user may be capturing images of different scenes or the same scene with different lighting which makes the uncertainty problem worse since each subsequent observation in terms of the neighboring intensities of a given pixel may be different in nature. To compensate for this problem and add robustness to the SPRT, a weighting procedure may be incorporated as described below.
FIG. 5 ( a ) illustrates a weighting function for a Stuck Low defect.
Since the content of each image (observation) is unknown, there may be conditions which yield abnormal likelihood ratios at those observations. For instance, if for a given observation, the P 0 (y) value is extremely low and approximately equal to zero, then that observation's likelihood ratio would approach infinity. As such, if this measurement is added to the accumulated likelihood ratio (score), then the score would abruptly increase, perhaps yielding a false conclusion. For instance, consider that the center of the distribution for a stuck low defect is approximately “b”, the intensity value of the pixel yielding the MND, and thus the determination of the pixel score is dependent upon the neighboring pixel intensity. If a stuck low pixel were surrounded by low neighboring pixel intensities then it would be more difficult to decide based upon that observation whether that pixel is stuck low or not. Neighboring pixel intensity may be defined be “b”, the intensity value of the pixel location yielding the MND.
Where neighboring pixel intensity is in the high end for yet another observation of that same stuck low pixel location, the likelihood ratio will be more meaningful and thus can be afforded more emphasis. To offset abnormal observations, each likelihood ratio obtained at each observation is weighted rather than being included in equal measure. The weighting function W SL (y) which varies from a minimum of zero (excluding the observation in the score) to a maximum of one (including the observation with full emphasis). As shown in FIG. 5 ( a ), above a certain threshold neighboring intensity, individual likelihood ratios are given full or almost full emphasis and thus have weighting equaling or approaching one. Below that threshold, when the neighboring intensity is low, the emphasis on the observation is diminished and may even be weighted by a zero which would exclude the observation from the accumulated likelihood ratio.
In FIG. 5 ( b ), a weighting function for a Stuck High defect is illustrated. A Stuck High pixel is one who returns a high intensity value for a given illuminant, near the very top of the range of possible intensities, even though the same illuminant when exposed to a functioning pixel, would return a low or medium intensity value. When detecting Stuck High defect, an observed likelihood is more relevant where the neighboring intensity is not high. Thus, in a weighting function for Stuck High defects, an observation where the neighboring intensity is high is given, according to a embodiment of the invention, less emphasis or maybe excluded from the accumulated likelihood ratio (i.e., the score) altogether by being given zero emphasis. Below a certain threshold, the weighting factor increases to one or near one consistent with the desired effect that observations where neighboring intensity is low should be given more or full emphasis in the score.
In detecting defective pixels, a first hypothesis will claim that a particular pixel location is functional or non-defective while a second will claim that the location is defective. In such probabilistic determinations, there is a likelihood that the decision made or hypothesis proven is incorrect even though the conditions for determination were satisfied. Incorrect results take the form of either a “false detection” or “miss detection.” A “false detection” would result in a functional pixel being classified as defective while a “miss detection” would result in a defective pixel being classified as functional. In mapping out an image sensor for defective pixels, as long as defective pixels are detected properly, it is acceptable to have a small number of functional pixels that are mis-classified as being defective Thus, in detecting, the number of false detections are to be minimized in relation to miss detections which are to be avoided altogether.
FIG. 6 is a block diagram of an image processing apparatus according to an embodiment of the invention.
FIG. 6 is a block diagram of internal image processing components of an imaging device incorporating at least one embodiment of the invention including an adaptive encoder. In the exemplary circuit of FIG. 6, a sensor 600 generates pixel components which are color/intensity values from some scene/environment. The n-bit pixel values generated by sensor 600 are sent to a capture interface 610 . Sensor 600 in the context relating to the invention will typically sense one of either R, G, or B components from one “sense” of an area or location. Thus, the intensity value of each pixel is associated with only one of three (or four if G 1 and G 2 are considered separately) color planes and may form together a Bayer pattern raw image. These R, G and B color “channels” may be compressed and encoded separately or in combination, whichever is desired by the application. Capture interface 610 resolves the image generated by the sensor and assigns intensity values to the individual pixels. The set of all such pixels for the entire image is in a Bayer pattern in accordance with typical industry implementation of digital camera sensors.
It is typical in any sensor device that some of the pixel cells in the sensor plane may not respond to the lighting condition in the scene/environment properly. As a result, the pixel values generated from these cell may be defective. These pixel locations are called “defective pixels.” In one embodiment of the invention, a “pixel substitution” unit 615 may replace the value read out in each dead pixel by the intensity value immediate previously valid pixel in the row. A RAM 616 consists of the row and column indices of the dead pixels, which are supplied by the defective pixel substitution methodologies presented in various other embodiments. The methodology for detecting which pixels in the sensor are defective may be carried out by a computer system or other such device as illustrated in FIG. 7 . The resulting tally of row and column indices of the defective pixel locations may be loaded into RAM 616 via the bus 660 which facilitates data transfer in bi-directional capacity between the imaging apparatus and external devices. In an alternate embodiment substitution unit 615 may be eliminated from the imaging apparatus in favor of some form of post-processing, such as filtering or averaging, after the image is downloaded or is ready to be displayed.
In the imaging apparatus, companding module 625 is designed to convert each original pixel of n-bit (typically n=10) intensity captured from the sensor to an m-bit intensity value, where m<n (typically, m=8). Companding module 625 is not needed if the sensor 600 and capture interface 610 provide a standard 8-bit per-pixel value. Defective pixel detection should be performed in accordance with the relevant intensity range of the sensor which if originally is a higher bi-resolution such as 10-bit, should consider the high end of the intensity range to be 1023 and not 255 (for 8-bit intensity values) as discussed above.
A primary compressor 628 receives companded sensor image data and performs image compression such as JPEG or DWT. A RAM 629 can be used to store DWT coefficients and/or quantization thresholds for each channel/sub-band as desired in executing such compression. Primary compressor 628 can be designed to provide outputs which are sensitive or corrective of defective pixel locations and their values, sending such compressed values to Encoder/Data Packer 630 .
Each of the RAM tables 616 , 626 , 629 and 631 can directly communicate with a bus 660 so that their data can be loaded and then later, if desired, modified. Further, those RAM tables and other RAM tables may be used to store intermediate result data as needed. When the data in storage arrays 640 is ready to be transferred external to the imaging apparatus of FIG. 6 it may be placed upon bus 660 for transfer. Bus 660 also facilitates the update of RAM tables 616 , 626 , 629 and 631 as desired. Depending on the design of the apparatus, a diagnostic capture mode may be provided that performs limited or no compression and no data correction while the identifying defective pixels is being undertaken.
FIG. 7 is a system diagram of one embodiment of the invention.
FIG. 7 illustrates a computer system 710 , which may be any general or special purpose computing or data processing machine such as a PC (personal computer), coupled to a camera 730 . Camera 730 may be a digital camera, digital video camera, or any image capture device or imaging system, or combination thereof and is utilized to capture an image of a scene 740 . Essentially, captured images are processed by an image processing circuit 732 so that they can be efficiently stored in an image memory unit 734 , which may be a RAM or other storage device such as a fixed disk. The image(s) contained within image memory unit 734 that is destined for computer system 710 can be according to one embodiment of the invention, for the purpose of determining the defective pixel locations of the camera 730 . In most digital cameras that can perform still imaging, images are stored first and downloaded later. This allows the camera 730 to capture the next object/scene quickly without additional delay. The use of a computer system 710 , particularly in detecting defective pixel locations of the camera, reduces the computation/storage requirements of the camera 730 allowing for a less complex and thus, more inexpensive manufacture.
The image processing circuit 732 carries out the pixel substitution (if any), companding and compression of images captured by the camera 730 . When a captured image, whether compressed or raw, is downloaded to computer system 710 , it may be decoded and then rendered to some output device such as a printer (not shown) or to a monitor device 720 . The execution of the defective pixel detection methodology described above, and image decompression, if needed, may be achieved using a processor 712 such as the Pentium™ processor with MMX Technology (a product of Intel Corporation) and a memory 711 , such as RAM, which is used to store/load instruction addresses and result data.
The application(s) used to perform the detecting of defective pixels based on a series of images downloaded from camera 730 may be from an executable compiled from source code written in a language such as C++. The instructions of that executable file, which correspond with instructions necessary to scale the image, may be stored to a disk 718 or memory 711 . Further, such application software may be distributed on a network or a computer-readable medium for use with other systems.
When an image, such as an image of a scene 740 , is captured by camera 730 , it is sent to the image processing circuit 732 . Image processing circuit 732 consists of ICs and other components which may execute, among other functions, the compression of the image pixel data set compensated by defective pixel correction. The image memory unit 734 will store the compressed/encoded image data. Once all pixels are processed and stored or transferred to the computer system 710 for rendering the camera 730 is free to capture the next image. When the user or application desires/requests a download of images, the encoded image data in the image memory unit, are transferred from image memory unit 734 to the I/O port 717 . I/O port 717 uses the bus-bridge hierarchy shown (I/O bus 715 to bridge 714 to system bus 713 ) to temporarily store the data into memory 711 or, optionally, disk 718 . Computer system 710 has a system bus 713 which facilitates information transfer to/from the processor 712 and memory 711 and a bridge 714 which couples to an I/O bus 715 . I/O bus 715 connects various I/O devices such as a display adapter 716 , disk 718 and an I/O port 717 , such as a serial port. Many such combinations of I/O devices, buses and bridges can be utilized with the invention and the combination shown is merely illustrative of one such possible combination.
According to one embodiment of the invention, the detecting of defective pixels may be achieved on computer system 710 by downloading and analyzing a series of images from camera 730 . The defective pixel location data may be stored in a disk, memory 711 or other storage mechanism and can be used in perform correction or enhancement of any downloaded image. Post download correction of defective image locations eliminates the need for incorporating such features into the camera 730 . Computer system 710 during pixel detection will perform such computations as the computing of likelihood ratios, weighting and accumulation of same as well as comparison of scores with boundary or stop conditions, and computation of MNDs. The computer system is also more ideally suited to storing the large number of data points required in compiling a histogram or distribution of values.
The exemplary embodiments described herein are provided merely to illustrate the principles of the invention and should not be construed as limiting the scope of the invention. Rather, the principles of the invention may be applied to a wide range of systems to achieve the advantages described herein and to achieve other advantages or to satisfy other objectives as well. | What is disclosed is a method comprising performing an observation on a sensor having a plurality of pixels, for each of the pixels that are unclassified, determining a score according to the observation, if the score for the each pixel satisfies a stopping condition, classifying the each pixel as being one of either defective or functional, and repeating the steps of performing, determining and classifying for any the pixels remaining unclassified after determining the score. | 7 |
FIELD OF THE INVENTION
This invention relates to a self-propelled irrigation machine or system and more particularly to a method and means for preventing the system from overturning in a high wind situation. Even more particularly, this invention prevents the system from overturning in a high wind situation by mounting a water tank on at least some, if not all, the drive units. The water tanks are filled with water for ballast when the system is not in operation. The water tanks are drained when the system is going to irrigate.
DESCRIPTION OF THE RELATED ART
Some irrigation systems or machines such as center pivot systems, lateral move systems and corner irrigation systems have a tendency to overturn or “tip over” when subjected to high winds. The overturning of the systems is at least partially due to the fact that the systems are top-heavy since the water pipeline or boom is positioned several feet above the main frame of the drive units.
SUMMARY OF THE INVENTION
A method and means for preventing a self-propelled irrigation system from overturning when subjected to a high wind condition is disclosed. Self-propelled irrigation systems such as lateral move irrigation systems and center pivot irrigation systems include an elongated water pipeline which is supported along its length by a plurality of spaced-apart drive units or towers. A ballast water tank is preferably mounted on all the drive units of the irrigation systems. A water conduit extends from the water pipeline to the ballast water tank and an electrically operated and remotely controlled switch is imposed in the conduit to enable water from the pipeline to be introduced into the ballast water tank when the irrigation system is not being used to irrigate. The tank is also provided with a discharge opening or drain opening which is also selectively opened and closed by means of an electric switch which is also remotely controlled. When the irrigation system is to remain stationary for a period of time during non-irrigating periods, the ballast water tanks are filled with water and the weight thereof acts as a ballast to prevent the system from overturning when subjected to high winds. When the system is going to be used to irrigate, the ballast water tanks are drained to reduce the weight thereof and to reduce stress on the drive unit.
It is therefore a principal object of the invention to provide a method and means for preventing a self-propelled irrigation system from overturning in a high wind situation.
Another object of the invention is to provide a means for preventing a self-propelled irrigation system from overturning in a high wind situation by mounting a ballast water tank on at least some of the drive units of the irrigation system, and preferably all of the drive units, with the ballast water tanks being selectively filled with water from the pipeline.
Still another object of the invention is to provide a means for preventing a self-propelled irrigation system from overturning which may be installed on the self-propelled irrigation system without extensive modification thereof.
These and other objects will be apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial perspective view of a self-propelled irrigation system having the invention mounted on the drive units thereof;
FIG. 2 is an end view of the invention mounted on a drive unit; and
FIG. 3 is a side view of the invention mounted on a drive unit.
DETAILED DESCRIPTION OF THE INVENTION
The numeral 10 refers to a conventional center pivot irrigation system which is conventional in design except for the means of this invention which is designed to prevent the overturning of the system during periods of high wind. Center pivot irrigation machine 10 is commonly referred to as a self-propelled irrigation system. Another type of self-propelled irrigation system is what is termed a lateral move irrigation system. The invention disclosed herein will work equally as well on center pivots as on lateral move systems. Further, the means of this invention will also work on irrigation systems which are described as corner pivot irrigation machines which are center pivot irrigation machines having a swing arm assembly mounted at the outer end thereof.
If a corner pivot irrigation system or a center pivot irrigation system is being utilized, the system 10 will include a center pivot structure 12 having a water conduit or pipeline 14 supported upon a plurality of drive units or towers 16 . Lateral move irrigation systems do not utilize a center pivot structure but simply travel across a field rather than rotating around a center pivot structure as does a center pivot irrigation system. Each of the drive units 16 includes a main frame 18 having drive wheels 20 and 22 mounted at the opposite ends thereof. A support frame 24 interconnects the main frame 18 with the pipeline 14 . Normally, the support frame 24 includes a pair of support members 26 and 28 which are secured to one end of the main frame 18 and which extend upwardly and inwardly therefrom in a diverging fashion with the upper ends thereof being connected to the pipeline 14 . Similarly, support frame 24 includes a pair of support members identical to support members 26 and 28 which are secured at their lower ends to the other end of main frame 18 and which extend upwardly and inwardly therefrom in a diverging relationship towards the pipeline 14 with the upper ends thereof being secured to the pipeline 14 .
The numeral 30 refers to a ballast water tank which is mounted on at least some of the drive units 16 , and preferably on all of the drive units 16 so as to prevent the overturning of the system when the system is subjected to high winds. For purposes of description, tank 30 will be described as having an upper end 32 , lower end 34 , inner side wall 36 , outer side wall 38 , and opposite end walls 40 and 42 . The lower end of the tank 30 is operatively secured to and supported upon the main frame 18 and is also preferably secured to the support frame 24 by any convenient means. When the ballast water tank 30 is viewed from either its inner or outer side, the water tank 30 defines a generally triangular shape ( FIG. 2 ). When the ballast water tank is viewed from either of its end walls, the tank generally defines an inverted triangle shape ( FIG. 3 ). As seen in FIG. 3 , the width of the tank 30 is greater at its upper end than at its lower end so that when the tank is filled with water for ballast, the increased width at the top of the tank will allow for freezing of the water without rupturing the tank.
Water conduit 44 is connected to the pipeline 14 and extends downwardly to the tank 30 so that water from the pipeline 14 may be introduced into the interior of the tank as desired. For that purpose, an electrically operated and remotely controlled valve 46 is imposed in the conduit 44 . Tank 30 is provided with a discharge opening or drain opening 48 which is selectively closed and opened by means of an electrically operated valve 50 which is also remotely controllable. The valves 46 and 50 could be hydraulically controllable if so desired.
Normally, when the irrigation system is being used to irrigate, the ballast tanks 30 will be empty. If the system is going to be shut down for a period of time, the valves 46 are remotely opened and the valves 50 are remotely closed. Water from within the pipeline 14 fills the tanks 30 and the weight of the tanks and the water therein acts as a ballast for the drive units so that the system will not overturn in a high wind situation. The increased width of the tank at its upper end, as described above, prevents the tank from rupturing should the water in the tank freeze. When the tanks 30 are filled, valves 46 are closed.
When the system is going to be used to again irrigate, the valves 50 are remotely opened so that the water in the tanks 30 will be discharged therefrom to reduce the weight on the drive unit. During the draining of the tanks 30 , the valves 46 are obviously closed to prevent further water from entering the tanks from the water pipeline.
Although it is preferred that the tanks 30 be filled from the pipeline 14 , a separate water line could be extended along the length of the system for filling the tanks.
Thus it can be seen that a novel method and means has been provided for preventing an irrigation system such as a center pivot irrigation system, a lateral move irrigation system or a corner pivot irrigation system from overturning in high wind situations.
Thus it can be seen that the invention accomplishes at least all of its stated objectives. | A selectively fillable ballast water tank is secured to the main frame of the drive units of a self-propelled irrigation machine. The water tank is selectively filled with water from the water pipeline when the system is going to remain stationary for a period of time, thereby reducing the risk that the drive unit will overturn when experiencing a high wind situation. The ballast water tanks are drained when the system is going to be used to irrigate. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates generally to carbon brushes for use as current collectors in dynamoelectric machines and, more particularly, to a method of treating blanks for such brushes and the brushes resulting therefrom, such brushes exhibiting enhanced wear characteristics particularly at high temperature and low humidity.
Carbon current collection brushes are employed in rotating brush-type machines in which the brush blanks are generally fabricated of carbon, a relatively poor electrical conductor, reinforced by other materials and graphitized. For example, carbon is mixed with a pitch binder and the mixture is graphitized. The blanks are then assembled into brushes. These brushes are referred to as carbon current collection brushes or merely carbon brushes.
The above types of carbon brushes are retained in position by brush holders which generally are in the form of square, rectangular or cylindrical sleeves serving as a guide for any radial motion of brush resulting from vibration or eccentricity of the armature (commutator or slip ring) and brush wear. The brush holder may be mounted on a bracket to maintain a rigid position spaced from the commutator surface. An adjustable spring, connected to the bracket, bears on the top surface of the brush to maintain the desired contact pressure of the bottom surface of the brush on the commutator segments or slip ring.
The wear rate of a carbon brush in a dynamoelectric machine increases very rapidly with increasing temperature. For example, the life of a typical carbon brush under a standard load of 100 amperes per square inch (APSI) for a brush wear of 250 mils, decreases from about 8,500 hours at 100° C. to about 700 hours and 200° C. An important contributing factor to increased brush wear at elevated temperatures is direct oxidation of the carbon brush surface at the sliding contact interface leading to loss of carbon as gaseous oxides. This oxidation is catalyzed by the presence of copper in the commutator or slip ring. Minute particles of copper oxide migrate along the basal planes of the graphite crystallites into the interior of the brush producing a catalytic effect that leads to enhanced gasification rates and to increased brush porosity. Various approaches have been employed in attempts to overcome rapid brush wear, including the use of lubricants.
One method of increasing brush life by decreasing wear is found in U.S. Pat. No. 3,841,906 "Method of Treating a Carbon Current Collection Brush Blank and Brush Resulting Therefrom" by Albert L. Grunewald et al., issued Oct. 15, 1974, which patent is assigned to assignee of the present invention and which patent is hereby specifically incorporated by reference. The above patent describes a treatment method and resultant brush with enhanced wear characteristics, particularly at high temperature and low humidity. The method defined by the Grunewald et al. patent calls for impregnating a brush blank by contacting that blank with a solution of zinc naphthenate and then curing the blank by air drying and heating to remove solvents and retain zinc naphthenate in the blank in the amount of approximately four to six percent by weight of the total blank.
The brush described and made in accordance with the method of U.S. Pat. No. 3,841,906 is superior in many respects to an untreated blank. It has been found, however, to exhibit a relatively high coefficient of friction between the brush and motor commutator (or slip ring) particularly under low load, low current operation of the dynamoelectric machine. This high friction condition can result in "chattering" of the brush in its holder with resultant poor commutation (including sparking) which could ultimately result in damage to the machine part, particularly the commutator or slip ring.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an improved method of treating a carbon brush blank and to provide an improved brush resulting therefrom.
It is an additional object to provide an improved method of treating a carbon brush blank to provide a brush which exhibits improved wear characteristics, particularly at elevated temperatures and low humidity, and which also exhibits a relatively low coefficient of friction between the brush and a contacting surface.
It is a further object to provide an improved method of treating a carbon brush blank to provide an improved carbon collector brush by impregnating the blank with an organometallic compound and an organic resin.
It is still another object to provide an improved method of treating a carbon brush blank and to the improved brush resulting therefrom by impregnating the brush blank with a solution of zinc naphthenate and organic resin and baking the brush to remove volatile solvents and cure the resin to provide a brush having approximately one to nine percent by weight of zinc naphthenate and resin.
The foregoing and other objects are achieved in accordance with the present invention by contacting a carbon brush blank with a solution containing an organometallic compound and an organic resin to thereby impregnate the brush with the solution. The brush is then baked to remove solvents and cured to retain the organometallic compound and resin in the blank at approximately one to nine percent of the weight of the brush blank. The brush resulting from the method has been found to have improved wear characteristics and low friction at its contacting surface.
BRIEF DESCRIPTION OF THE DRAWING
While the present invention is described in particularity in the claims annexed to and forming a part of this specification, a better understanding thereof can be had from the following description taken in conjunction with the accompanying drawing which is a side elevational view, partially in section, of a carbon brush such as is made in accordance with our invention provided within a brush holder assembly.
DETAILED DESCRIPTION
Before beginning a description of the method of treating the carbon brush and the brush resulting therefrom, reference is made to the drawing which sets forth a suitable environment for use of the brush in accordance with the present invention. In the FIGURE, there is shown a single brush holder assembly 10 including the improved carbon current collection brush 11. Brush 11 comprises a body portion 12 and a lower surface portion 13 which surface is in contact with or rides on the surface of a commutator (or a slip ring) 14 due to the force of the spring applied by a brush spring 15 against the top portion 12 of the brush 11. Brush 11 is maintained in the desired position relative to the commutator (slip ring) 14 by means of a brush holder 16 which is held in fixed position spaced from the surface of commutator 14 by means of a bracket 17. Brush holder 16 is shown of conventional design, comprising a rectangular sleeve fabricated of high strength metal and serves as a guide for any radial motion of the brush 11 resulting from vibration or eccentricity of the armature or commutator and wear of the brush. For purposes of simplicity, a flexible copper cable generally described as a brush shunt or pig tail employed for directing current from the carbon brush to the brush holder, is not illustrated but can be employed as desired.
As is known and earlier alluded to, due to friction and other effects, as the brush 11 rides upon the rotating commutator 14, there is wear associated with the brush which is a function of a number of factors, primarily temperature, humidity and the coefficient of friction between the brush and the commutator or slip ring.
It is the purpose of the present invention to provide a method of treatment and the resultant brush to provide the requisite current carrying capability of the brush while providing improved wear characteristics thereof. The current collection carbon brush in accordance with the present invention is made by impregnating a brush blank with a treating solution comprising an organometallic compound and a an organic resin, diluted with appropriate solvents, and subsequently curing the blank, preferably first by air drying and then by heating, to remove volatiles (e.g., solvents) and cure the resin to retain organometallic compound and resin in the resultant brush in the amount of approximately one to nine percent by weight of the brush.
The organometallic compounds employed in the present invention are preferably organometallic salts of the carboxylate family of the metals: zinc, calcium, cobalt, lead, manganese and zirconium. The carboxylates preferred are selected from naphthenate, octoates, tallates. A preferred embodiment of the invention employs a metal carboxylate solution having a metal content of from 5 to 40 percent. A zinc naphthenate solution containing from 8 to 16 percent zinc is, at the present, most preferred.
The organic resins preferred are epoxy and phenolic resins. In the category of epoxy resins, that preferred is a resin having 1, 2 epoxy groups and having more than one epoxy group per molecule. The epoxy resins thus include cycloaliphatic epoxy resins, such as 3,4-epoxycyclohexylmethyl-(3,4-epoxy)cyclohexane carboxylate (sold under the trademarks ERL 4221 by Union Carbide Plastics Company or Araldite CY 179 by Ciba Products Company); bis (3,4-epoxy-6-methylcyclohexymethyl) adipate (sold under the trademarks ERL 4289 by Union Carbide Plastics Company or Araldite CY 178 by Ciba Products Company); vinylcyclohexene dioxide (ERL 4206 made by Union Carbide Plastics Company); bis (2,3 -epoxycyclopentyl) ether resins (sold under the trademark ERL 4205 made by Union Carbide Plastics Company); 2-(3,4-epoxy) cyclohexyl-5,5-spiro (3,4-epoxy)cyclohexane-m-dioxane (sold under the trademark Araldite CY 175 by Ciba Products Company); glycidyl ethers of polyphenols epoxy resins, such as liquid or solid bisphenol A diglycidyl ether epoxy resins (such as those sold under trademarks as Epon 826, Epon 828, Epon 830, Epon 1001F, Epon 1002F, Epon 1004F, etc., by Shell Chemical Company); phenolformaldehyde novolac polyglycidyl ether epoxy resins (such as those sold under the trademarks DEN 431, DEN 438, and DEN 439 by Dow Chemical Company); epoxy cresol novolacs (such as those sold under the trademarks ECN 1235, ECN 1273, ECN 1280 and ECN 1299 by Ciba Products Company); resorcinol glycidyl ether (such as ERE 1359 made by Ciba Products Company); tetraglycidoxy tetraphenylethane (Epon 1031 made by Shell Chemical Company); glycidyl ester epoxy resins such as diglycidyl phthalate (ED-5661 sold by Celanese Resins Company); diglycidyl tetrahydrophthalate (Araldite CY 182 by Ciba Products Company); and diglycidyl hexahydrophthalate (Araldite CY 183 made by Ciba Products Company or ED-5662 made by Celanese Resins Company); and flame retardant epoxy resins such as halogen containing bisphenol A diglycidyl ether epoxy resins (e.g., DER 542 and DER 511 which have bromine contents of 44-48 and 18-20 percent, respectively, and are made by Dow Chemical Company). Moreover, it often is advantageous to employ mixtures of these epoxy resins; e.g., a glycidyl ether epoxy resin such as Epon 828 with a cycloaliphatic epoxy resin such as ERL 4221.
When a phenolic resin is used in the present invention, it can be any of those based upon reacting formaldehyde with phenol, cresols, furan, butyl phenols, catechol, resorcinol or mixtures of these compounds. The phenolic resin can also be modified such as with an epoxy resin, a rubber or an oil. Examples of these phenolic materials are CRJ 406, FRJ 425, FRJ 774, HRJ 1166, HRJ 1461, HRJ 1871, HRJ 2148, HRJ 254, SG 3350 and SG 3378 made by Schenectady Chemicals Inc. (Schenectady, N.Y.) and Varcum phenolic and furan resins made by Reichold Chemicals, Inc. (White Plains, N.Y.).
The preferred process for treating the brush blank in accordance with the present invention involves disolving the solid resins and diluting liquid resins with appropriate volatile solvents such as alcohol, toluene, alcohol/toluene, methyl ethyl ketone, acetone, etc., to achieve a desired specific gravity for treating the brush. In accordance with the present invention, the preferred solution specific gravity is in the range of from 0.900 to 1.020 at 21° C. The brush blank is then placed into a vacuum pressure vessel and a vacuum of about 28 inches of mercury or better is applied for approximately 30 minutes. With the material still under vacuum, the treating solution is drawn into the vessel to completely cover the blank. With the carbon pieces completely submerged in the solution, atmospheric pressure is then applied for approximately one-half hour to cause the solution to completely impregnate the carbon. In cases of blanks greater than approximately one inch in thickness, it is often advisable to apply nitrogen at a pressure of approximately 45 pounds per square inch gauge for approximately one-half hour to speed the impregnation process.
Following the pressure period, the carbon pieces are removed from the solution, drained and allowed to air dry for approximately 16 to 24 hours. After air drying, a heat treatment is applied to effect the final curing of the brush. Preferably, this treatment involves heating from about 30° C. to 220° C. at a rate of increase of about 20° C. per hour. Once the brush reaches 220° C., it is held at that temperature for approximately 12 hours at which time the curing process is complete.
The following teaching examples are included as illustrative of the invention. It is to be specifically noted that Example A falls within the teachings of the aforementioned U.S. Pat. No. 3,841,906 and not the present invention. It is included here for purposes of illustration and comparison. The curing process used in all cases was in accordance with that described above. "Pick up" as used in the following examples refers to the weight percentage of the treating materials to the total brush weight after curing. Treating solution percentages are on a "by weight" basis.
EXAMPLE A
(U.S. Pat. No. 3,841,906)
A treating solution having a specific gravity of 0.908 at 27° C. was made from 69.5% of zinc naphthenate solution containing 10% zinc and 30.5% of toluene. The pick up was 3.5-5%.
EXAMPLE B
A treating solution having a specific gravity of 1.016 at 20° C. was made from 62.9% of the cycloallphatic epoxy resin ERL 4221, 7.0% of zinc napthenate solution containing 10% zinc and 30.1% methyl ethyl ketone. The pick up was 6-9%.
EXAMPLE C
A treating solution having a specific gravity of 0.952 at 23° C. was made from 24.8% of furan modified phenol-formaldehyde resin HRJ 2148, 24.8% of a zinc naphthenate solution containing 10% zinc and 50.4% of denatured ethyl alcohol/toluene (50/50 by volume). The pick up was 4-7%.
EXAMPLE D
A treating solution having a specific gravity of 0.928 at 21° C. was made from 24.8% of rubber modified phenol-formaldehyde resin HRJ 2630, 24.8% of zinc naphthenate solution containing 10% zinc and 50.4% denatured ethyl alcohol/toluene (50/50 by volume). The pick up was 4-7%.
The test results for the brushes described in Examples A to D are summarized in Table I below.
TABLE I__________________________________________________________________________TEST DATA WEAR RATE (MILS/HR) AMBIENT: 50% REL. HUMIDITY CONTROLLED BRUSH TEMP UNCONTROLLED AMBIENTEXAMPLE FRICTION COEFF 150° C. BRUSH TEMP -40° C. DPTBRUSH CURRENT → NO LOAD 100 APSI 100 APSI 150 APSI 100 APSI__________________________________________________________________________A 0.56 0.37 0.08 0.09 0.18B 0.21 0.11 0.09 0.22 0.14C 0.18 0.18 0.12 0.17 0.15D 0.24 0.22 0.15 0.07 0.12__________________________________________________________________________
From Table I above, it is seen that a carbon current collection brush in accordance with the present invention (Examples B-D) exhibits a reduced coefficient of friction while retaining the improved wear characteristics of the zinc napthenate treated brush described in the aforementioned patent (Example A).
It has been further found that the improved characteristics of the present invention can be experienced over a wide range of proportions in the treating solutions. Table II below illustrates this:
TABLE II__________________________________________________________________________TEST DATA WEAR RATE (MILS/HR) AMBIENT: 50%TREATING SOLUTION REL. HUMIDITY RUBBER MOD. CONTROLLEDZN NAPTH. PHENOL- BRUSH TEMP UNCONTROLLED AMBIENT(10% ZN) FORMALDEHYDE FRICTION COEFF 150° C. BRUSH TEMP -40° C. DPTBRUSH CURRENT → NO LOAD 100 APSI 100 APSI 150 APSI 100 APSI__________________________________________________________________________10% 90% 0.29 0.22 0.170 0.373 0.2525% 75% 0.30 0.16 0.084 0.73 4.2050% 50% 0.24 0.22 0.152 0.70 0.12575% 25% 0.20 0.18 0.086 0.325 0.14__________________________________________________________________________
While there have been shown and described what are at present considered to be the preferred embodiments of the invention, modifications thereto will readily occur to those skilled in the art. It is not desired, therefore, that the invention be limited to the specific arrangements shown and described, but it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention. | A carbon current collection brush having improved wear characteristics and exhibiting a relatively low coefficient of friction at its sliding contact surface (e.g., with a commutator or slip ring) is made by impregnating a brush blank with a solution containing an organometallic compound and an organic resin. The thereby impregnated brush blank is then cured to remove volatiles and retain approximately one to nine percent, by weight, of the organometallic compound and the organic resin in the brush blank. | 8 |
This is a division of application Ser. No. 07/941,600, filed Sep. 18, 1992, now U.S. Pat. No. 5,290,929, which is a continuation-in-part of U.S. Ser. No. 07/608,945, filed Nov. 5, 1990, now abandoned.
BRIEF DESCRIPTION OF THE INVENTION
Compounds having the formula ##STR2## having antibacterial activity are described herein. In formula 1, and throughout the specification, the symbols are as defined below.
R 1 and R 2 are the same or different and each is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, substituted phenyl or a 4, 5, 6 or 7-membered heterocycle (hereinafter referred to as R a ), or one of R 1 and R 2 is hydrogen and the other is azido, halomethyl, dihalomethyl, trihalomethyl, alkoxycarbonyl, phenylethyl, 2-phenylethenyl, 2-phenylethynyl, carboxyl, --CH 2 X 1 [wherein X 1 is azido, amino, hydroxy, carboxyl, alkoxycarbonyl, alkanoylamino, phenylcarbonylamino, (substituted phenyl) carbonylamino, alkylsulfonyloxy, phenylsulfonyloxy, (substituted phenyl) sulfonyloxy, phenyl, substituted phenyl, cyano, ##STR3## --S--X 2 , or --O--X 2 wherein A, X 2 , X 6 and X 7 are as hereinafter defined], --S--X 2 or --O--X 2 [wherein X 2 is alkyl, substituted alkyl, phenyl, substituted phenyl, phenylalkyl, (substituted phenyl)alkyl, formyl, alkanoyl, substituted alkanoyl, phenylalkanoyl, substituted phenylalkanoyl, phenylcarbonyl, substituted phenylcarbonyl, heteroaryl, heteroarylalkyl, heteroarylalkanoyl or heteroarylcarbonyl, and in the case of when X 1 is --O--X 2 then X 2 can also be alkylideneamino, alkanoylamino, carboxyalkylideneamino, alkylsulphinylamino, alkoxycarbonyl or alkylsulphonylamino. In addition R 1 and R 2 can be ##STR4## [wherein one of X 3 and X 4 is hydrogen and the other is hydrogen or alkyl, or X 3 and X 4 when taken together with the carbon atom to which they are attached form a cycloalkyl group; and X 5 is formyl, alkanoyl, phenylcarbonyl, substituted phenylcarbonyl, phenylalkylcarbonyl, substituted phenylalkylcarbonyl, carboxyl, alkoxycarbonyl, aminocarbonyl, substituted aminocarbonyl, or cyano] or ##STR5## [wherein A is --CH═CH--, --(CH 2 ) m --, --(CH 2 ) m --O--, --(CH 2 ) m --NH--, or --CH 2 --S--CH 2 --, where m is 0, 1 or 2, and X 6 and X 7 are the same or different and each is hydrogen, alkyl, phenyl or substituted phenyl, or X 6 is hydrogen an X 7 is amino, substituted amino, alkanoylamino or alkoxy, or X 6 and X 7 when taken together with the nitrogen atom to which they are attached form a 4, 5, 6 or 7-membered heterocycle];
X is --(CH 2 ) n -- wherein n is 0 or an integer of 1 to 4 or CR 3 R 4 wherein R 3 and R 4 are the same or different and each is hydrogen, --CH 3 or --C 2 H 5 or R 3 and R 4 taken together with the carbon atom to which they are attached form a 3, 4, 5, 6 or 7-membered cycloalkyl ring; M is hydrogen, tetraalkylammonium, sodium, potassium or any other cation capable of forming a pharmaceutically acceptable salt.
Preferred compounds are when X is --CH 2 --. The preferred compound is illustrated in Examples eleven and twenty. The compounds of this invention are pictured as acids or salts. They can also exist, however, as zwitterions (internal or inner salts), and these are also included within the language "pharmaceutically acceptable salts" and the scope of this invention. Further, it is intended that amino acid salts such as L-arginine and L-lysine are within the scope of "pharmaceutically acceptable salts."
Listed below are definitions of various terms used to describe the β-lactams of this invention. These definitions apply to the terms as they are used throughout the specification (unless they are otherwise limited in specific instances) either individually or as part of a larger group.
The terms "alkyl" and "alkoxy" refer to both straight and branched chain groups. Those groups having 1 to 10 carbon atoms are preferred.
The term "cycloalkyl" refers to cycloalkyl groups having 3, 4, 5, 6 or 7 carbon atoms.
The term "substituted alkyl" refers to alkyl groups substituted with one or more (preferably 1, 2 or 3) azido, amino (--NH 2 ), halogen, hydroxy, carboxy, cyano, alkoxycarbonyl, aminocarbonyl, alkanoyloxy, alkoxy, phenyloxy, (substituted phenyl)oxy, R a -oxy, mercapto, alkylthio, phenylthio, (substituted phenyl)thio, alkylsulfinyl, or alkylsulfonyl groups.
The terms "alkanoyl", "alkenyl", and "alkynyl" refer to both straight and branched chain groups. Those groups having 2 to 10 carbon atoms are preferred.
The term "substituted alkanoyl" refers to alkanoyl groups substituted with one or more (preferably 1, 2 or 3) azido, amino (--NH 2 ), halogen, hydroxy, carboxy, cyano, alkoxycarbonyl, aminocarbonyl, alkanoyloxy, alkoxy, phenyloxy, (substituted phenyl)oxy, mercapto, alkylthio, phenylthio, (substituted phenyl)thio, alkylsufinyl or alkylsulfonyl groups.
The term "substituted phenyl" refers to a phenyl group substituted with 1, 2 or 3 amino (--NH 2 ), halogen, hydroxyl, trifluoromethyl, alkyl (of 1 to 4 carbon atoms), alkoxy (of 1 to 4 carbon atoms), alkanoyloxy, aminocarbonyl, or carboxy groups.
The expression "a 4, 5, 6 or 7-membered heterocycle" (referred to as "R a ") refers to substituted and unsubstituted, aromatic and non-aromatic groups containing one or more (preferably 1, 2 or 3) nitrogen, oxygen or sulfur atoms. Exemplary substituents are oxo (═O), halogen, hydroxy, nitro, amino, cyano, trifluoromethyl, alkyl of 1 to 4 carbons, alkoxy or 1 to 4 carbons, alkylsulfonyl, phenyl, substitued phenyl, 2-furfurylideneamino ##STR6## benzylideneamino and substituted alkyl groups (wherein the alkyl group has 1 to 4 carbons). One type of "4, 5, 6 or 7-membered heterocycle" is the "heteroaryl" group. The term "heteroaryl" refers to those 4, 5, 6 or 7-membered heterocycles which are aromatic. Exemplary heteroaryl groups are substitued and unsubstituted pyridinyl, furanyl, pyrrolyl, thienyl, 1, 2, 3-triazolyl, 1,2,4-triazolyl, imidazolyl, thiazolyl, thiadiazolyl, pyrimidinyl, oxazolyl, triazinyl and tetrazolyl. Exemplary nonaromatic heterocycles (i.e., fully or partially saturated heterocyclic groups) are substituted and unsubstituted azetidinyl, oxetanyl, thietanyl, piperidinyl, piperazinyl, imidazolidinyl, oxazolidinyl, pyrrolidinyl, tetrahydropyrimidinyl, dihydrothiazolyl and hexahydroazepinyl. Exemplary of the substituted 4, 5, 6 or 7-membered heterocycles are 1-alkyl-3-azetidinyl, 2-oxo-1-imidazolidinyl, 3-alkylsulfonyl-2-oxo-1-imidazolidinyl, 3-benzylideneamino-2-oxo-1-imidazolidinyl, 3-alkyl-2-oxo-1-imidazolidinyl, 3-phenyl (or substituted phenyl)-2-oxo-1-imidazolidinyl, 3-benzyl-2-oxo-1-imidazolidinyl, 3-(2-aminoethyl)-2-oxo-1-imidazolidinyl, 3-amino-2-oxo-1-imidazolidinyl, 3-[alkoxycarbonyl)amino]-2 -oxo-1-imidazolidinyl, 3-[2-[(alkoxycarbonyl)amino]ethyl]-2-oxo-1-imidazolidinyl, 2-oxo-1-pyrrolidinyl, 2-oxo-3-oxazolidinyl, 4-hydroxy-6-methyl-2-pyrimidinyl, 2-oxo-1-hexahydroazepinyl, 2-oxo-3-pyrrolidinyl, 2-oxo-3-tetrahydrofuranyl, 2,3-dioxo-1-piperazinyl, 2,5-dioxo-1-piperazinyl, 4-alkyl-2,3-dioxo-1-piperazinyl, and 4-phenyl-2, 3 -dioxo -1 -piperazinyl.
The term "substituted amino" refers to a group having the formula --NX 8 X 9 wherein X 8 is hydrogen, alkyl, phenyl, substituted phenyl, phenylalkyl or (substituted phenyl)alkyl, and X 9 is alkyl, phenyl, substituted phenyl, phenylalkyl, (substituted phenyl)alkyl, hydroxy, cyano, alkoxy, phenylalkoxy or amino.
DETAILED DESCRIPTION OF THE INVENTION
The β-lactams of formula 1 have activity against gram-positive and gram-negative organisms. Of particular interest is the good activity against gram negative organisms in vitro and in vivo exhibited by the compounds of this invention. The compound of this invention can be used as agents to combat bacterial infections (including urinary tract infections and respiratory infections) in mammalian species, such as domesticated animals (e.g., dogs, cats, cows, horses, and the like) and humans.
For combating bacterial infections in mammals, a compound of this invention can be administered to a mammal in need thereof in an amount of about 1.4 mg/kg/day to about 350 mg/kg/day, preferably about 14 mg/kg/day to about 100 mg/kg/day. All modes of administration which have been used in the past to deliver penicillins and cephalosporins to the site of the infection are also contemplated for use with β-lactams of this invention. Such methods of administration include oral, intravenous, intramuscular, and as a suppository.
The compounds of this invention can be prepared by coupling a compound having the formula ##STR7## wherein R 5 is hydrogen or a suitable protecting group such as formyl or trityl with a compound of the formula ##STR8## wherein R 6 is hydrogen or a suitable phenol-protecting group or R 6 /R 6 is a catechol protecting group such as Si(t-butyl) 2 , R 7 is hydrogen or a suitable protecting group such as t-butyl or diphenylmethyl and HY is a mineral acid, sulfonic acid or another non-nucleophilic acid capable of forming a stable hydroxylamine salt and m is 0, 1, or 2 or fractions of 1 or 2. All synthesis of compounds using intermediates carrying protecting groups such as R 5 , R 6 , and R 7 in formulae 2, 3 and 6 provide protected derivatives of 1 which must be finally deprotected.
Alternatively, the compounds of formula 1 can be prepared by reacting a compound of the formula ##STR9## wherein Z is a leaving group such as halogen, trifluoroacetate, alkylsulfonate, arylsulfonate or other activated esters of alcohols; wherein R 6 is the same as above with the proviso that if R 5 is trityl then R 6 may also be benzyl or another protecting group which can be removed by catalytic hydrogenation and R 7 is the same as above with the proviso that in compound 4, R 7 may also be allyl, trimethylsilylethyl or other non-sterically crowded carboxyl protecting group with a compound of the formula ##STR10## wherein R 5 is a defined above and R 8 is hydrogen or a carboxyl protecting group which can be removed under conditions wherein R 7 remains inert. If R 5 is trityl then R 8 may also be p-nitrobenzyl to form a compound of the formula ##STR11## wherein R 5 , R 6 , R 7 and R 8 have hereinbefore been defined. Compound 6 is then reacted with a compound of the formula ##STR12## to form compounds of the invention represented by formula 1.
Compound 6 can also be formed by reacting compound 3 with a compound of the formula ##STR13## wherein R 5 and R 8 are as hereinbefore defined.
Compound 3 can be prepared from compound 9 by total or partial removal of the protecting groups R 6 , R 7 , R 9 , R 10 . ##STR14##
Also, the cyclic hydroxamic acids of formula 10 can be hydrolyzed (HCl conc., ca 80°) to form the hydroxylamines of formula 3. ##STR15##
Alternatively, compound 3 can be prepared from compound 11 by desoxygenation and total or partial removal of the protecting group R 6 , R 7 , R 9 , R 10 . ##STR16##
Compounds 9 and 11 can be prepared by reacting a compound of formula 12, with a N-protected derivative of hydroxylamine of the formula 13 in an organic solvent and in the presence of a base such as K 2 CO 3 or triethylamine. ##STR17##
In the case of m=0 formula 12 is identical with formula 4. Hence, all definitions of R 6 , R 7 , X and Z are specified as in formula 4. Instead of activated esters of alcohols as leaving groups Z, the alcohols themselves (Z═OH) can be used if the alcohols are preactivated by using e.g. Mitsunobu conditions (PPh 3 /DEAD/THF). ##STR18##
In formula 13, R 11 and R 12 are combinations of suitable protecting groups such as H, t-butyloxy-carbonyl (BOC), benzyloxy-carbonyl or R 11 and R 12 taken together form a divalent, cyclic protective group such as isopropylidene group (CH 3 ) 2 C or a phthalyl group. In the case of R 11 =R 12 =BOC ((BOC) 2 NOH) compound 13a is novel and forms an integral part of this invention. In formula 9 and 11, R 9 and R 10 are equivalent to R 11 and R 12 in formula 13.
Compound 13a is made by reacting a compound of the formula 14 ##STR19## with di-t-butyldicarbonate in a mixture of water, tetrahydrofuran (THF) and NaOH to form a compound of the formula 15. Intermediate 15 is also reported in the literature: R. Sulsky and J. P. Demers, Tetrahedron Letters, 30, (1989), 31-34. ##STR20##
Compound 15 is reacted with di-t-butyldicarbonate in tetrahydrofuran and 4-dimethylaminopyridine to form a compound of the formula 16. ##STR21##
Compound 16 is hydrogenated in the presence of palladium on activated carbon to form compound 13a.
Compound 12 can be prepared by halogenation (e.g. NBS) of the corresponding alkyl substituted compound 17. ##STR22## wherein R 3 , R 4 is defined previously or by conversion of the correponding N-oxides of the formula 18 with acetylchloride or trifluoroacetic anhydride. The acetate group introduced in this manner is subsequently displaced by halide ion and in the case when m is one in formula 18 the remaining N-oxide moiety is deoxygenated to afford a compound of formula 12. ##STR23##
In order to prepare compounds of formula 1 when n is zero, compounds of formula 4 wherein Z is halogen and X is a single bond are prepared by reacting compounds of the formula ##STR24## with POCl 3 . A compound of formula 18a is equivalent to a compound of formula 4 when Z is OH and n is zero.
Alternatively, compound 12 can be prepared by conversion of the Z--X group in 12 to a modified Z'--X' group as exemplified in the following Scheme 1 and Scheme 2. Formula 19 is identical with formula 12 if Z=Hal, X=CH 2 and m=0; formula 19 is also identical with formula 4 if Z=Hal and X=CH 2 . ##STR25## Formula 24 is identical with formula 4 if Z=OH and X=(CH 2 ) n .
Aldehydes 21 (n=3,4) with suitable protective groups R 13 such as acetate, benzyl etc. are known from the literature. Alternatively, compound 22 can be prepared via the following scheme 2. ##STR26##
The necessary Wittig reagent 26 (n=4) with a suitable protective group R 13 , such as benzyl, is known from the literature.
Alternatively, compound of formula 12 with m=0 and Z=OR 13 or H can be prepared by reacting a compound of formula 27 wherein X is CR 3 R 4 or (CH 2 ) n ; n=1,2,3,4 (as defined previously) and Z is hydrogen or a suitable protected hydroxy group (as defined previously) with ##STR27## a compound of formula 28 wherein R 6 is a suitable phenol-protecting group (as defined previously) or R 6 /R 6 is a catechol protecting group (as defined previously). ##STR28##
Instead of compound of the formula 27, derivatives thereof such as hydrates or bisulfite adducts can be used. Compound of formula 27 can be prepared from compounds of the formula 29 by direct oxidation (e.g. by means of SeO 2 ) or by indirect oxidation (e.g. nitrosation followed by treatment with N 2 O 4 or condensation with dimethoxy dimethylamino methane followed by ozonolysis). ##STR29## X=CR 3 R 4 ; (CH 2 ) n ; n=1,2,3,4 D=H, OR 13
R 7 =as defined previously
Compounds of formula 28 can be prepared by reduction of corresponding dinitro compounds as exemplified for the isopropylidene-protected derivative 28 (R 6 /R 6 =C(CH 3 ) 2 ) in U.S. Pat. No. 4,904,757, Example 3D.
Alternatively, compound 28 can be prepared by reduction of a protected amino-nitro-catechol as exemplified for the dibenzyl protected derivative 33 (24, R 6 =CH 2 --C 6 H 5 ) in scheme 3. ##STR30##
The dibenzyl confound 33 is novel and forms an integral part of this invention.
Compound 18 with m=1 can be prepared by oxidation of compound 17 by means of peroxy acids or by reacting a compound of formula 34 (wherein R 6 is defined as previously) with a compound of formula 29 (wherein X and D are defined as previously). ##STR31##
Compound 34 can be prepared by reacting compound 35 with NaN 3 in dimethyl sulfoxide. ##STR32##
The isopropylidene-protected derivative 35 (R 6 /R 6 =C(CH 3 ) 2 ) is disclosed in U.S. Pat. No. 4,904,775. Replacement of the isopropylidene protecting group by other protecting groups can be achieved by hydrolysis removal (HCl conc./80° C.) of the isopropylidene group and subsequent protection of 4,5-dinitrocatechol with another phenol/or catechol-protecting group. Obviously, such a replacement of a protective group by another protective group R 6 can also be performed on a later stage of the synthesis as exemplified by the following scheme 4. ##STR33##
The preferred method of preparation for the preferred compound of Example 20 involves the following sequence.
Examples 20A→20B→21 →3→8→9→20H→20I.
The compounds of formula 1 contain at least
one chiral center-the carbon atom (in the 3-position of the β-lactam nucleus) to which the acylamino substituent is attached. This invention is directed to those β-lactams which have been described above, wherein the stereochemistry at the chiral center in the 3-position of the β-lactam nucleus is the same as the configuration at the carbon atom in the 6-position of naturally occurring penicillins (e.g., penicillin G) and as the configuration at the carbon atom in the 7-position of naturally occurring cephalosporins (e.g., cephalosporin C).
The compounds of formula 1 have the imino substituent ##STR34## and can, therefore, exist as the syn or anti isomer or as a mixture of isomers. All of these isomeric forms are within the scope of this invention. In general, however, the syn isomer of a compound of formula 1 has the greatest activity.
The freeze dried or lyophilized L-arginine salts of the compounds of formula I are prepared by mixing the required amount of the formula I compound and 90% of the required L-arginine together. For example, for a 1 gram sample of the compound ([2R-[2α,3α(Z)]]-3-[[[[1-(2-amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)-amino]-2-oxoethylidene]amino]oxy]methyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid) the required amount of L-arginine is 0.58 to 0.65 grams to bring the pH of the solution to preferably about 5.5. Alternatively, based on in-process titration, 100% of the L-arginine required for preparation is used to bring the pH of the solution to about 5.5. This solution is prepared by dissolving the dry mixture of the formula I compound and L-arginine in about 90% of the required amount of water. After the pH has been adjusted to preferably about 5.5 with more L-arginine, if required, the solution is brought to final volume with water. The solution is clarified and filtered, if required. The solution is then freeze dried by conventional methods. Similar methods known to those skilled in the art may be utilized to form other amino acid salts of the compounds of formula I.
The following examples are specific embodiments of this invention.
EXAMPLE 1
t-Butyl-2,3-dioxobutyrate
The above compound was prepared according to the procedure described by H. Dahn, H. Cowal and H. P. Schlunke, Helv. Chim. Acta. 53, 1598 (1970) by oxidation (N 2 O 4 ) of t-butyl-2-oximino-3-oxo-butyrate. M.P. 62°-66° C.
EXAMPLE 2
2,2,7-Trimethyl-1,3-dioxolo-[4,5-g]-quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
[5,6-diamino-2,2-dimethyl-1,3-benzodioxole; dihydrochloride salt] (U.S. Pat. No. 4,904,775, Example 3D) (6.8 g, 0.02 mmol) was dissolved in a mixture of 25 ml water and 10 ml tetrahydrofuran and the pH of the solution was adjusted to 5.5 by the addition of 2N NaOH. After addition of the compound from Example 1 (3.8 g; 0.02 mol) the mixture was refluxed for 2 hours, concentrated in vacuo to remove the organic solvent tetrahydrofuran and then extracted with ethyl acetate. The combined organic phases were washed with brine, dried (Na 2 SO 4 ) and then evaporated in vacuo to leave an oil which crystallized by the addition of petroleum ether.
M.P. 104°-105° C.; yield 5.2 g (82%). C 17 H 20 N 2 O 4 % C calc. 64.54%, found 64.40% % H calc. 6.37%, found 6.41% % N calc. 8.85%, found 8.86% IR(KBr): 1710 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=1.65 (s, 9H); 1.81 (s, 6H); 2.73 (s, 3H) 7.34 (s, 1H); 7.42 (s, 1H) ppm; 13 C-NMR(DMSO-d 6 ): δ=21.95 (q); 25.28 (q); 27.46 (q); 82.22 (s); 102.94 (d); 103.50 (d); 120.43 (s); 137.24 (s); 140.28 (s); 142.50 (s); 147.94 (s); 150.16 (s); 151.43 (s); 164.61 (s).
EXAMPLE 3
7-Bromomethyl-2,2-dimethyl-1,3-dioxolo-[4,5-g]-quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
To a solution of the compound from Example 2 (7.8 g, 24.6 mmol) in 150 ml dry tetrachloromethane, N-bromosuccinimide (4.38 g, 24.6 mmol) and a trace of azobisisobutylronitrile (AiBN) were added and the suspension was refluxed for 3 hours. Over this period of time, small additional quantities of the catalyst (AiBN) were added. After cooling, the formed succinimide was filtered off (2.1 g) and the filtrate was evaporated in vacuo to leave an oil which was chromatographed on silica gel eluting with ethylacetate/toluene (1:6). Evaporation of the relevant fractions yielded the corresponding dibromo derivative (0.8 g; 7%) as side product, the desired monobromo compound (6.5 g, 67%) as main product and recovered starting material (1.8 g; 23%). Recrystallization of the monobromo compound from petroleum ether (bp 60°-80° C.) containing a trace of ethyl acetate afforded a pure sample of title compound; m.p. 130.5° C.-131.5° C.; yield 4.85 g (50%).
IR(KBr): 1728 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=1.63 (s, 9H); 1.81 (s, 6H); 4.97 (s, 2H) 7.41 (s, 1H); 7.48 (s, 1H) ppm; 13 C-NMR(DMSO-d 6 ): δ=24.16 (q); 27.43 (q); 31.82 (t); 82.91 (s); 103.14 (d); 103.63 (d); 121.18 (s); 138.62 (s); 140.13 (s); 141.53 (s); 146.98 (s); 151.59 (s); 152.24 (s), 163.53 (s) ppm.
EXAMPLE 4
t-Butyl-N-benzyloxycarbamate
To a stirred solution of O-benzylhydroxylamine (16.0 g; 0.13 mol) and di-t-butyldicarbonate (28.4 g; 0.13 mol) in a mixture of water (150 ml) and tetrahydrofuran (150 ml) 2N NaOH solution was added dropwise to adjust the pH to 8-9 and this pH was maintained for an additional 2 hours by occasional addition of 2N NaOH. After extraction with ethylacetate the combined organic layers were washed with brine, dried (MgSO 4 ) and evaporated in vacuo to leave an oil which was used in the next example without any further purification; yield 29 g (100%).
EXAMPLE 5
(Phenylmethoxy)imidodicarbonic acid, bis(1,1-dimethylethyl) ester
To a stirred solution of the compound of Example 4 (29 g; 0.13 mol) triethylamine (27.9 ml; 0.2 mol) and 4-dimethylamino-pyridine (trace) in dry tetrahydrofuran (200 ml) a solution of di-t-butyl dicarbonate (39.7 g; 0.18 mol) in 20 ml dry tetrahydrofuran was added dropwise at a rate that temperature did not exceed 40° C. Stirring was continued at this temperature (40° C.) for additional 30 minutes and then at room temperature overnight. The mixture was taken up in ether, washed with buffer solution pH=4 (citrate) and brine, dried (MgSO 4 ) and evaporated in vacuo. From the oily residue (still containing few ml of ether) the title compound was crystallized by cooling to 0° C.; m.p. 77.5°-78.5° C.; yield 70.4%; an analytical sample was recrystallized from petroleum ether (bp 40°-60° C.); m.p. 77.5°-78.5° C. C 17 H 25 NO 5 % C calc. 63.14%, found 63.14% % H calc. 7.79%, found 7.82% % N calc. 4.33%, found 4.35% IR(KBr): 1755 1730cm -1 : 1 H-NMR(DMSO-d 6 ): δ=1.49 (s, 18H); 4.88 (s, 2H), 7.42 (s, 5H)ppm.
EXAMPLE 6
Hydroxyimidodicarbonic acid, bis(1,1-dimethylethyl)ester
A solution of the compound of Example 5 (8.09 g, 0.025 mol) in ethanol (150 ml) was hydrogenated in the presence of palladium (10%) on activated carbon (3.5 g). After 15 minutes the hydrogenation was completed (monitored by thin layer chromatography), the catalyst was removed by suction and the filtrate was evaporated in vacuo. The oily residue solidified by stirring with pentane; m.p. 88.5°-89.5° C., yield 71.2%; an analytical sample was recrystallized from petroleum ether (60°-70° C.); m.p. sint 88.7° C., 91°-92° C.
C 10 H 19 NO 5 % C calc. 51.49%, found 51.48% % H calc. 8.21%, found 8.21% % N calc. 6.00%, found 6.02% IR(KBr): 1775 1752, 1685cm -1 1 H-NMR(DMSO-d 6 ): δ=1.48 (s, 18H); 9.95 (s, 1H).
EXAMPLE 7
(2R-cis)-3-[[[2-(Formylamino)-4-thiazolyl]-oxoacetyl]amino]-2-methyl-4-oxo-1-azetidine-sulfonic acid, N,N,N-tributyl-1-butanammonium salt
To a suspension of (2R-cis)-3-[[[2-(Formylamino)-4-thiazolyl]-oxoacetyl]amino]-2-methyl-4-oxo-1-azetidine-sulfonic acid, monopotassium salt as described in Example 16A (10.0 g; 0.025 mol) in water (250 ml) tetrabutylammoniumhydrogensulfate (9.33 g; 0.027 mol) was added and the pH was adjusted to 5.5-6.0 by the addition of 2N KOH. The mixture was extracted thrice with chloroform (100 ml, 60 ml, 60 ml) and the combined organic layers were washed with few ml water, dried (MgSO 4 ) and evaporated in vacuo to leave a viscous foam which solidified by stirring with petroleum ether (bp 60°-80° C.); the solid was collected by suction and dried in vacuo over P 2 O 5 ; mp=82°-88.5° C. dec; yield 11.6 g (77%). C 26 H 45 N 5 O 7 S 2 % C calc. 51.72%, found 50.96% % H calc. 7.51%, found 7.61 % % N calc. 11.60%, found 11.30% % N calc. 10.62% found 10.40%
IR(KBr): 1760 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=0.89 (t, 12H); 1.22 (d, 3H; J=7 Hz); 1.15-1.75 (m, 16H); 3.00-3.25 (m, 8H); 4.02 (quin(ps), 1H, J'=6 Hz); 5.05 (d,d, 1H, J'=6 Hz, J"=8.5 Hz); 8.41 (s, 1H); 8.54 (s, 1H); 9.60 (d, 1H, J"=8.5 Hz); 12.68 (s, 1H).
EXAMPLE 8
7-[[[Bis[1,1-dimethylethoxy)carbonyl]amino-oxy-]methyl]-2,2-dimethyl-1,3-dioxolo[4,5g]-quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
Finely ground potassium carbonate (2.71 g; 19.6 mmol), N,N-diBOC-hydroxylamine (title compound of Example 6) (1.43 g; 6.13 mmol) and a trace of sodium iodide were added to a suspension of the compound of Example 3 (1.94 g; 4.9 mmol) and stirring was continued for 3 hours at room temperature. The solvent was removed in vacuo and the residue was taken up in ethyl acetate, washed twice with buffer solution pH 3 (citrate) and, dried (Na 2 SO 4 ). Evaporation of the solvent in vacuo yielded an oil (4.4 g) which was purified chromatographically on silicagel eluting with ethyl acetate/toluene (1:3). The relevant fractions were combined, evaporated in vacuo to leave the title compound as an oil, which was used in the next step without any additional purification. yield 2.21 g (92%); mp=91°-94° C. (from hexane).
IR(film): 1790, 1750-1710 cm -1 1 H-NMR(DMSO-d 6 ): δ=1.27 (s, 18H); 1.60 (s, 6H); 1.79 (s, 3H); 5.32 (s, 2H); 7.43 (s, 1H); 7.50 (s, 1H) ppm.
EXAMPLE 9
3-[(Aminooxy)methyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid, hydrochloride
A suspension of the compound of Example 8 (4.1 g; 7.5 mmol) in 60 ml conc. HCl was heated at 80°-85° C. for 90 minutes. Over this period of time the starting material of Example 8 was dissolved to form finally a new precipitate. After cooling to 0° C. the precipitate was collected by suction, washed with few ml conc. HCl and dried in vacuo over P 2 O 5 ; yield 1.9 g (88%)
C 10 H 9 N 3 O5.1.6 HCl. 0.5 H 2 O % C calc. 37.71%, found 38.64% % H calc. 3.67%, found 3.48% % N calc. 13.19%, found 12.80% % Cl calc. 17.81% found 17.70% IR(KBr): 1720 cm -1 ; 1 H-NMR (D 2 O): δ=5.32 (s 2H); 6.53 (s, 1H); 6.63 (s, 1H) ppm.
EXAMPLE 10
[2R-[2α,3α(Z)]]-3-[[[[1-[2-(Formylamino)-4-thiazolyl]-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]-amino]oxo]methyl]-6,7-dihydroxy-2-quinoxalinecarboxy acid, disodium salt
The compound of Example 7 (9.6 g; 0.015 mol) was dissolved in water (80 ml) and the pH of the filtered solution was lowered to 2.0 by the addition of 2N HCl. Then the hydrochloride salt of Example 9 (1.44 g; 5.0 mmol ) was added in small portions while the pH of the solution was corrected constantly to 2.0 by addition of 2N NaOH. Stirring at this pH (2.0) was continued for additional 4.5 hours, then the pH of the suspenion was adjusted to 5.5-6.0 by addition of 2N NaOH and the nearly clear solution was filtered and freeze-dried. The obtained powder was redissolved in water (75 ml), filtered again and passed through a column with Dowex 50 W×8.20-50 mesh (Na + -form). Freeze-drying of the relevant fractions yielded 5.6 g of an orange, crude material which was chromatographed (MPLC) on XAD-2 resin eluting with water to remove inter alia recovered sodium salt of the starting material of Example 7. Fractions containing the title compound with an HI≧85% by HPLC (yield 15%) were rechromatographed on XAD-2 resin eluting with water to yield after freeze-drying an yellowish powder with an HI=95.1% by HPLC.
IR(KBr): 1755 cm -1 1 H-NMR(DMSO-d 6 ): δ=1.14 (d, 3H; J=7 Hz), 4.00 (quin (ps), 1H; J=7 Hz; J'=6 Hz); 5.15 (dd, 1H J'=6 Hz; J"=9 Hz); 5.55 (d, 1H; J=14 Hz); 5.70 (d, 1H; J=14 Hz); 6.76 (s, 1H); 6.98 (s, 1H); 7.38 (s, 1H); 7.38 (s, 1H); 8.46 (s, 1H); 9.97 (d, 1H; J"=9 Hz) ppm.
EXAMPLE 11
[2R-[2α,3α(Z)]]-3-[[[[1-(2-Amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]methyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid
To a solution of 228 mg (0.36 mmol) of the compound of Example 10 (HI=95% by HPLC) in 90 ml water, 27 ml tetrahydrofuran were added and then the pH of the solution was lowered to pH=0.8-1.0 by the addition of 2N hydrochloric acid. The mixture was stirred at room temperature for 20 hours to deformylate ca. 90% of the starting material Example 10, (proven by HPLC). The precipitated yellowish zwitterion title compound was collected by suction, washed with water and purified by redissolving in 10 ml water at pH 5.5-6.0 (addition of 0.5N NaOH) and reprecipitation at pH 1.0 (addition of 2N HCl ). After stirring for additional 30 minutes the precipitate was collected by suction, washed with few ml water and dried in vacuo over P 2 O 5 to yield 90 mg title compound with an HI of 97%; mp >200° decomposes.
IR(KBr): 1740 cm -1 1 H-NMR(DMSO-d 6 ): δ=1.02(d, 3H; J=7 Hz); 3.97 (quin (ps), 1H; J=7 Hz; J'=6 Hz); 5.06 (dd, 1H, J'=6 Hz, J"=8 Hz); 5.63 (d, 1H, J=14 Hz); 5.70 (d, 1H; J=14 Hz) 6.91 (s, 1H); 7.28 (s, 1H); 7.30 (s, 1H); 9.42 (d, 1H; J"=8 Hz) ppm.
EXAMPLE 12
(2S-trans)-3-[[[2-(Formylamino)-4-thiazolyl]-oxoacetyl]amino]-2-methyl-4-oxo-1-azetidine-sulfonic acid, tetrabutylammonium (1:1) salt
To a suspension of (2S-trans)-3-[[[2-(Formylamino)-4-thiazolyl]-oxoacetyl]amino]-2-methyl-4-oxo-1-azetidine-sulfonic acid, monopotassium salt (10.0 g; 0.025 mol) in water (250 ml), tetrabutylammonium-hydrogensulfate (10.32 g; 0.030 mol) was added and the pH was adjusted to 5.5-6.0 by the addition of 2N KOH. The mixture was extracted three times with chloroform (100 ml, 70 ml, 70 ml) and the combined organic layers were washed with a few ml water, dried (MgSO 4 ) and evaporated in vacuo to leave a viscous foam which solidified by stirring with petroleum ether (bp 60°-80° C.); the solid was collected by suction and dried in vacuo over P 2 O 5 ; mp=82° C. (sint), 120.5° C. dec; yield: 13.23 g (87%).
C 26 H 45 N 5 O 7 S 2 % C calc. 51.72%, found 51.03% % H calc. 7.51% , found 7.51% % N calc. 11.60% , found 11.60% IR(KBr): 1770, 1670 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=0.91 (t, 12H); 1.43 (d, 3H); J=7 Hz); 1.10-1.80 (m, 16H); 3.00-3.30 (m, 8H); 3.82 (dq), 1H; J=7 Hz, J'=3 Hz); 4.46 (dd, 1H, J'=3 Hz, J"=8 Hz); 8.54 (s, 1H); 8.57 (s, 1H); 9.78 (d, 1H, J"=8 Hz); 12.68 (s, broad, 1H).
EXAMPLE 13
[2S-[2α,3β(Z)]]-3-[[[[1-[2-Formylamino)-4-thiazolyl]-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethyliene]amino]oxy]methyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid, disodium salt
The compound of Example 12 (4.53 g; 7.5 mmol) was dissolved in water (40 ml) and the pH of the filtered solution was lowered to 2.0 by the addition of 2N HCl Then the hydrochloride salt of Example 9 (1.44 g; 5.0 mmol) was added in small portions while the pH of the solution was corrected constantly to 2.0 by addition of 2N NaOH. Stirring at this pH (2.0) was continued for additional 4.5 hours, then the pH of the suspension was adjusted to 5.5-6.0 by addition of 2N NaOH and the nearly clear solution was filtered and freeze-dried. To replace the tetrabutylammonium cation by the Na-cation the so obtained powder was redissolved in water (40 ml), filtered again and passed through a column with Dowex 50W×8, 20-50 mesh (Na+-form). Freeze-drying of the relevant fractions yielded 5.0 g of an orange, crude material which was chromatographed (MPLC) on XAD-2 resin eluting with water to remove recovered sodium salt of the starting material of Example 12.
Fractions containing the title compound with an HI≧88% by HPLC (yield 14%) were rechromatographed on XAD-2 resin eluting with water to yield after freeze-drying a yellowish powder with an HI=95.6% by HPLC: yield 140 mg (4.4%).
IR(KBr): 1760 cm -1 ; 1 H-NMR(DMSO-d 6 -TFA) δ=1.39 (d, 3H; J=7 Hz), 3.77 (dq), 1H; J=7 Hz), 4.44 (d), 1H; J'=3 Hz); 5.60 (d, 1H; J=14 Hz); 5.68 (d, 1H; J=14 Hz); 7.32 (s, 1H); 7.33 (s, 1H); 7.38 (s, 1H); 8.46 (s, 1H) ppm.
EXAMPLE 14
[2S-[2α, 3β(Z)]]-3-[[[[1-(2-Amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]methyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid
To a solution of 120 mg (0.19 mmol) (HI=93-95% by HPLC) in water (45 ml) tetrahydrofuran (13.5 ml) was added and then the pH of the solution was lowered to pH=0.8-1.0 by the addition of 2N hydrochloric acid. The mixture was stirred at room temperature for 27 hours to deformylate ca. 90% of the starting material (proven by HPLC). The still clear solution was concentrated in vacuo to half of its volume and the pH was adjusted to 1.0 by the addition of 0.5N NaOH. After cooling to 5° C. the precipitated yellowish zwitterion title compound was collected by suction, washed with ice water and purified by redissolving in 7 ml water at pH 5 (addition of 0.5N NaOH) and reprecipitation at pH 1.0 (addition of 2N HCl). After stirring for additional 30 minutes at 10° C. the precipitate was collected by suction, washed with a few ml ice water and dried in vacuo over P 2 O 5 to yield 70 mg (65%) title compound.
IR(KBr): 1760 cm -1 ; M.P.=>178° C. decomposes 1 H-NMR(DMSO-d 6 ): δ=1.37 (d, 3H; J=7 Hz); 3.72 (dq, 1H; J=7 Hz; J'=3 Hz); 4.42 (dd, 1H, J'=3 Hz, J"=8 Hz); 5.66 (s, 2H); 6.89 (s, 1H); 7.28 (s, 1H); 7.30 (s, 1H); 9.47 (d, 1H; J"=8 Hz ) ppm.
EXAMPLE 15
[2R-[2α,3α(Z)]]-3-[2-[[[1-(2-Amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]ethyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid
EXAMPLE 15A
3-oxo-5-(phenylmethoxy)pentanoic acid, 1,1-dimethylethyl ester
Analogous to the procedure described by Brooks, D. W., Kellogg, R. P. and Cooper, C. S., J. Org. Chem. 52 192, (1987) t-butyl acetate (33 ml; 0.20 mol) and benzyl chloromethylether (50 ml; 0.22 mol) were reacted. Chromatographic purification on silica gel eluting with petroleum ether/ethyl acetate (5:1) afforded the title compound as a viscous oil still containing ca 10% (by NMR) of t-butyl acetoacetate. This material was used in the next step without any additional purification. Yield 3.41 g (61%).
IR(film): 1738, 1712 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=1.34 (s, 9H); 2.72 (t, 2H; J=7 Hz); 3.43 (s, 2H); 3.60 (t, 2H; J=7 Hz); 4.39 (s, 2H); 7.27 (s(ps), 5 H) ppm.
EXAMPLE 15B
2-(Hydroxyimino)-3-oxo-5-(phenylmethoxy)pentanoic acid, (1,1-dimethylethyl) ester
With stirring and cooling (0° C.) a solution of sodium nitrite (1.5 g; 22 mmol) in water (5 ml) was dropped within 10 minutes into a solution of compound of Example 15A (5.56 g; 20 mmol) in acetic acid (3.0 g; 50 mmol) and stirring was continued at 0° C. for additional 10 minutes and at room temperature for 30 minutes. The reaction product was extracted with ether and the combined ether phases were washed with aqueous sodiumbicarbonate solution and brine. After drying (CaSO 4 ) the solvent was removed in vacuo to leave a residue (5.7 g) which solidified by treatment with petroleum ether (bp 60°-70° C.). Yield: 3.65 g (59.5%) mp: 98°-100° C. (mp: 100°-101° C. after recrystallization from ether-petroleum ether).
IR(KBr):1730, 1679 cm 1 ; 1 H-NMR(DMSO-d 6 ): δ=1.46(s, 9H); 3.02(t, 2H; J=7 Hz); 3.70(t, 2H; J=7 Hz); 4.45(s, 2H); 7.31 (s(ps), 5H); 13.10(s(broad), 1H) ppm.
EXAMPLE 15C
2-3-dioxo-3-(phenylmethoxy)butanoic acid 1,1-dimethylethyl ester, hydrate
Anhydrous sodium sulfate (10.0 g) was added to a solution of the compound of Example 15B (28.8 g; 94 mmol) in chloroform (250 ml) at -25° C. followed by a solution of dinitrogen tetroxide (4.4 g; 48.0 mmol) in dry chloroform (60 ml). After stirring at -25° C. for 5 hours the mixture was allowed to warm to room temperature within 4 days. After filtration (Na 2 SO 4 ) and removal of the solvent in vacuo the residual oil (30 g) was dissolved in ethyl acetate, washed with aqueous NaHCO 3 solution (10%) and brine. Drying (CaSO 4 ) and removal of the solvent on a rotary evaporator yielded an oil, which was used in the next step without any further purification: yield: 27.5 g (94%).
EXAMPLE 15D
2,2-Dimethyl-7-[2-(phenylmethoxy)ethyl]-1,3-dioxolo]4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
The freshly prepared, crude compound, 5,6-diamino-2,2-dimethyl)-1,3-benzodioxole, (16.4 g; 91 mmol) was taken up in a mixture of water (180 ml) and tetrahydrofuran (90 ml) and then the crude compound of Example 15C (27.5 g; ca 90 mmol) was added with stirring. The mixture was refluxed for 60 minutes at 80°-85° C. and then evaporated in vacuo to leave a residue which was partitioned between ethyl acetate (350 ml) and water (150 ml). After extraction of the aqueous phase with ethyl acetate the combined organic phases were washed with brine and dried (Na 2 SO 4 ). Removal of the solvent in vacuo gave an oily residue which was purified by chromatography on silica gel eluting with ethyl acetate/petroleum ether (bp 60°-70° C.). Yield: 20.2 g (51%).
IR(film): 1735, 1720 (sh) cm -1 ; 1 H-NMR (DMSO-d 6 ) δ=1.56(s, 9H); 1.77 (s, 6H); 3.31 (t, 2H; J=7 Hz); 3.81 (t, 2H)7; J=7 Hz); 4.44 (s, 2H); 7.23(s(ps), 5H); 7.30(s, 1H); 7.38 (s, 1H) ppm.
EXAMPLE 15E
7-(2-Hydroxyethyl)-2,2-dimethyl-1,3-dioxolo-[4,5g]quinoxaline-6-carboxylic acid, (1,1-dimethylethyl) ester.
The compound of Example 15D (10.5 g; 24.0 mmol) was dissolved in dimethylformamide (200 ml) and hydrogenated for 15 minutes in the presence of palladium (10%) on carbon (3.0 g). The catalyst was removed by filtration and the solvent was distilled off in vacuo. The residue was dissolved in ethyl acetate, washed with water and brine, dried (Na 2 SO 4 ) and evaporated in vacuo to leave a residual oil (8.1 g) which was chromatographically purified on silica gel eluting with ethyl acetate/petroleum ether (45:55). Yield 6.2 g (75%); mp 88°-90° C. (90°-92° from petroleum ether). C 18 H 22 N 2 O 5
______________________________________C.sub.18 H.sub.22 N.sub.2 O.sub.5Elemental analysis (%) Calc. Found______________________________________C 62.41 62.27H 6.40 6.37N 8.09 8.19______________________________________
IR(KBr): 1735 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=1.60(s, 9H); 1.79 (s, 6H); 3.18 (t, 2H; J=7 Hz); 3.78(q(ps), 2H; J=7 Hz; J'=7 Hz); 4.76(t, 1H); J'=7 Hz); 7.33 (s, 1H); 7.40(s, 1H) ppm.
EXAMPLE 15F
7-[2-[[Bis[(1,1-dimethylethoxy)carbonyl]amino]oxy]ethyl-2,2-dimethyl-1,3-dioxolo]4,5g]-quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
A solution of diethyl azodicarboxylate (5.0 g; 28.6 mmol) in dry tetrahydrofuran (40 ml) was dropped at room temperature into a mixture of the compound of Example 15E (9.9 g; 28.6 mmol), triphenylphosphine (7.5 g; 28.6 mmol) and Hydroxyimidodicarbonic acid, bis(1,1-dimethylethyl) ester (6.1 g; 26 mmol) in dry tetrahydrofuran (100 ml) and stirring was continued for 5.5 hours at room temperature. The solvent was removed in vacuo and the residue was purified by chromatography on silica gel eluting with petroleum ether/ethyl acetate (gradient 20-30%); first fractions contained the corresponding vinyl-compound (dehydrated starting material; yield 4.5 g; 53%), late fractions the desired titled compound; yield: 4.8 g (33%); viscous oil.
IR (film): 1785, 1750, 1720 cm -1 ; 1 H-NMR(DMSO-d 6 : δ=1.35 (s, 18 H); 1.59 (s, 9H); 1.78 (s, 6H); 3.37 (t, 2H); 7.33 (s, 1H); 7.41 (s, 1H) ppm.
EXAMPLE 15G
3-[2-(Aminooxy)ethyl]-6,7-dihydroxy-2-quinoxaline-2-carboxylic acid .HCl
In a simple vacuum distillation apparatus a mixture of the compound of Example 15F (1.8 g; 3.3 mmol) and conc. HCl (70 ml) was heated at 85°-90° C. and ca 700 mbar to distill off the generated acetone. After 90 minutes, the mixture was evaporated in vacuo to leave a yellow solid (1.0 g) which still contained ca 20% of the corresponding acetone-oxime of the title compound. Rehydrolysis of this solid with conc. HCl (40 ml) using the same conditions (85°-90° C.; 700 mbar) afforded after cooling (0° C.) a precipitate, which was collected by suction, washed with few ml conc. HCl and dried in vacuo over P 2 O 5 : yield 0.4 g (40%); mp:>300° C.; Hl=96% (by HPLC).
IR(KBr): 1750 cm -1 ; 1 H-NMR(DMSO-d 6 /trifluoroacetic acid 1:1): δ=3.56 (t, 2H); 4.42 (t, 2H); 7.32 (s, 1H); 7.38 (s, 1H) ppm.
EXAMPLE 15H
[2R-[2α,3α(Z)]]-3-[2-[[[1-[2-(Formylamino)-4-thiazolyl]-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]ethyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid, tetrabutylammonium (1:2) salt
The tetrabutylammonium salt of Example 7 (0.78 g; 1.30 mmol) was dissolved in water (35 ml) and the pH of the filtered solution was lowered to 1.9 by the addition of tetrabutylammonium hydrogen sulfate (0.21 g). Then the hydrochloride salt of Example 15G (0.39 g; 1.30 mmol) was added in small portions while the pH of the solution was corrected constantly to 2.0 by addition of a solution of tetrabutylammonium hydroxide in water (20%). Stirring at this pH (2.0) was continued for additional 4.0 hours, then the pH of the suspension was adjusted to 5.8 by addition of tetrabutylammonium hydroxide and the clear solution was freeze-dried to yield 2.5 g of an orange, crude material which was chromatographed (MPLC) on XAD-2 resin eluting with water-acetonitrile (15%).
The E-isomer was isolated from the first fractions (yield: 240 mg, 17%) whereas late fractions contained the pure isomer of the title compound yield: 355 mg (25%); mp: 110° sint, 134°-136° C.; Hl=97.7% by HPLC.
IR(KBr): 1765 cm -1 , 200 MHz- 1 H-NMR(DMSO-d 6 -TFA): δ=0.90(t, 24H); 1.15-1.42 (m, 16H) overlapped by 1.28 (d, 3H, J=7 Hz); 1.42-1.75 (m, 16H); 3.0-3.3 (m, 18H); 3.57 (t, 2H; J"=7 Hz); 4.00 (quin(ps), 1H, J=7 Hz, J'=6 Hz); 4.55 (t, 2H, J"'=7 Hz); 5.09 (d, 1H, J'=6 Hz); 7.26 (s, 1H); 7.32 (s, 1H); 7.35 (s, 1H); 8.48 (s, 1H) ppm.
EXAMPLE 15I
[2R-[2α,3α(Z)]]-3-[2-[[[1-(2-Amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxo]ethyl]-6,7-dihydroxy- 2-quinoxaline-carboxylic acid
To a solution of the tetrabutylammonium salt of Example 15H (317 rag, 0.29 mmol) purity=98% by HPLC) in water (72 ml) was added tetrahydrofuran (22 ml) and then the pH of the solution was lowered to a pH of 0.6 by the addition of 2N hydrochloride acid (15 ml). The mixture was stirred at room temperature for 18 hours and the precipitated yellowish zwitterion title compound was collected by suction, washed with a few ml ice-water and dried in vacuo over P 2 O 5 : yield: 105 mg (62.5%); mp:>300° C.; purity:98.6% (by HPLC). C 20 H 19 N 7 O 10 S 2 .2.5 H 2 O
______________________________________C.sub.20 H.sub.19 N.sub.7 O.sub.10 S.sub.2.2.5 H.sub.2 OElemental analysis Calc. Found______________________________________C 38.33 38.28H 3.86 3.95N 15.65 15.40______________________________________
IR(KBr): 1740 cm -1 ; 1 H-NMR(DMSO-d 6 /trifluoroacetic acid): δ=1.07(d, 3H, J=7 Hz); 3.65 (t, 2H); 3.98 (quintett(ps), 1H), J=7 Hz, J"=6 Hz); 4.68 (t, 2H); 5.02 (d, 1H, J'6 Hz); 6.89 (s, 1H); 7.28 (s, 1H); 7.40 (s, 1H); ppm.
EXAMPLE 16
Alternate Method for Preparation of [2R-[2α3α(Z)]]-3-[2-[[[1-(2-Amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]ethyl]-6,7-dihydroxy-2-quinxoalinecarboxylic acid
EXAMPLE 16A
(2R-cis)-3-[[[2-Formylamino)-4-thiazolyl]oxoacetyl]amino]-2-methyl-4-oxo-1-azetidine-sulfonic acid monopotassium salt
1,8-Diazobicyclo[5.4.0]undec-7-ene (DBU) (16.5 ml; 0.11 mol) was dropped into a suspension of the zwitterion (2R-cis)-3-Amino-2-methyl-4-oxo-1-azetidine-sulfonic acid, inner salt (18.02 g; 0.10 mol) in dry dichloromethane (180 ml) at 10° C. and stirring was continued at this temperature for an additional hour. Then the solution was cooled to -30° C. (solution A). Formylamino-thiazolylglyoxylic acid (22.22 g; 0.111 mol) was suspended in dry dichloromethane (360 ml) and then dissolved by addition of triethylamine (17.0 ml; 0.122 mol). After being stirred for 1 additional hour insoluble material was filtered off and the filtrate was cooled to -30° C. (solution B).
Into solution B was added dropwise at -30° C. pyridine (0.62 ml) followed by trimethylacetyl chloride (13.38 g; 0.111 mol) and then by solution A. The mixture was stirred at -25° to -30° C. for 1 hour and then allowed to come to ambient temperature. After evaporation in vacuo the residue was taken up in ethanol (600 ml) and treated dropwise with a solution of potassium acetate (28 g; 0.285 mol) in ethanol (180 ml). After being stirred for 1 hour the precipitate was collected by suction, washed with ethanol, dried in vacuo and purified by recrystallization from hot water (270 ml). Yield 28.4 g (70%); mp >230° C.
IR(KBr) 1755, 1670 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=1.22 (d, 3H); J=7 Hz); 4.07(quin(ps), 1H; J=7 Hz; J'=6 Hz); 5.11 (dd, 1H; J'=6 Hz; J"=8.5 Hz); 8.45 (s, 1H); 8.56 (s, 1H); 9.40 (d, 1H; J"=8.5 Hz); 12.70 (s, 1H) ppm.
EXAMPLE 16B
(2R-cis)-3-[[(2-Amino-4-thiazolyl)oxoacetyl]amino]-methyl-4-oxo-1-azetidine-sulfonic acid
The compound from Example 16A (20 g, 55.2 mmol) was suspended in 270 ml water. The pH was brought to 0.5 with 3N hydrochloric acid and the resulting solution was stirred for two days at room temperature. On taking a sample for tlc analysis, the title compound precipitated. It was filtered off with suction, washed with water and dried in vacuo. Yield 12.6 g (68.4%) m.p. >300° C.
IR(KBr): 1710, 1760 cm -1 (CO). 1 H-NMR(DMSO-d 6 ): δ=1.20 (d, 3H), 4.03 (dq, 1H), 5.02 (dd, 1H), 8.19 (s, 1H), 8.35 (s, broad, NH 2 , SO 3 H and water), 9.70 (d, 1H); ppm.
EXAMPLE 16C
[2R-[2α,3α(Z)]]-3-[2-[[[1-(2-Amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]ethyl]-6,7-dihydroxy-2-quinoxaine-carboxylic acid
The compound from Example 16B (0.33 g, 1.0 mmol) was suspended in water (15 ml) and the pH was adjusted to 5.5-6.0 by addition of a solution of tetrabutylammonium hydroxide in water (20%) to obtain a clear solution. The pH of this solution was lowered to 2.0 by the addition of tetrabutylammonium hydrogen sulfate (0.14 g). Then the hydrochloride salt of 3-[2-Aminooxy)ethyl]-6,7-dihydroxy-2-quinoxaline-2-carboxylic acid (0.5 g; ca 1.0 mmol; Hl by HPLC: 64%) (Example 15G) was added in small portions while the solution was corrected constantly to 2.0 by addition of a solution of tetrabutylammonium hydroxide in water (20%). Stirring at this pH (2.0) was continued for additional 4.5 hours, then the pH of the suspension was adjusted to 5.8 by addition of tetrabutylammonium hydroxide and the solution was freeze-dried to yield 1.7 g of an orange, crude material which was chromatographed (MPLC) on XAD-2 resin eluting with water-acetonitrile (gradient 10-15%). Freeze-drying of the appropriate fractions yielded 0.18 g (17%) of the di-tetrabutylammoniumsalt [2R-[2α,3α(Z)]]-3-[2-(Formylamino)-4-thiazolyl]-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]-ethyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid, from which the title compound was obtained by dissolving in water (15 ml) and precipitation at pH 2.0 (addition of 2N HCl). Yield: 50 mg (54%); mp: >dec. 198° C.
EXAMPLE 17
[2R-[2α,3α(Z)]]-3-[3-[[[1-(2-Amino-4-thiazolyl-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]propyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid
EXAMPLE 17A
7-[(Dimethoxyphosphinyl)methyl]-2,2-dimethyl-1,3-dioxolo[4,5-g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
A mixture of the compound of Example 3 (3.95 g; 10.0 mmol) and trimethyl phosphite (3.5 ml; 30.0 mmol) was heated in an oil bath at 140° C. for 30 minutes and the volatile components were distilled off during this period. On cooling, the residue was taken up in petroleum ether and evaporated in vacuo to leave a viscous oil (5 g), which was purified chromatographically on silica gel eluting with ethyl acetate. Evaporation of the appropriate fractions in vacuo afforded a colorless oil, which solidified by stirring with a few ml petroleum ether. Yield 2.77 g (65%); mp=86.3°-87.9° C. (from petroleum ether). C 19 H 25 N 2 O 7 P
______________________________________C.sub.19 H.sub.25 N.sub.2 O.sub.7 P Calc. (%) Found (%)______________________________________C 53.77 53.45H 5.94 6.08N 6.60 6.92______________________________________
IR(KBr): 1720 cm 31 1 ; 200 MHz- 1 H-NMR(DMSO-d 6 ): δ=1.57 (s, 9H); 1.75 (s, 6H); 3.58 (d, 6H, J( 31 P- 1 H)=11.0 Hz); 3.92 (d, 2H, J( 31 P- 1 H)=22.4 Hz); 7.36 (s, 1H); 7.42 (s, 1H) ppm.
EXAMPLE 17B
7-[3-Acetyloxy)-1-propenyl]-2,2-dimethyl-1,3-dioxolo[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
A solution (2.5 M) of n-butyllithium (12 ml; 30.1 mmol) was treated dropwise with a solution of diisopropylamine (4.2 ml; 30.0 mmol) in dry tetrahydrofuran (40 ml) with stirring at 0° C. The mixture was held at 0° C. for 30 minutes and then cooled to -30° C. A solution of the phosphonate of Example 17a (12.7 g; 30.0 mmol) in dry tetrahydrofuran (80 ml) was added dropwise and after being stirred at -30° C. for another 30 minutes, a solution of 2-acetoxy-acetaldehyde (3.06 g; 30.0 mmol) in dry tetrahydrofuran (60 ml) was added slowly. The mixture was allowed to come to ambient temperature and stirring was continued for an additional 2 hours at this temperature. The solvent was removed on a rotary evaporator and the residue was taken up in ethyl acetate and water and the pH was adjusted to 3 by the addition of 2N HCl. The organic layer was separated, washed with brine, and dried (MgSO 4 ). After removal of the solvent in vacuo the oily residue (14.9 g) was purified by chromatography on silica gel eluting with ethyl acetate petroleum ether (1.3) to give the title compound as a mixture of stereoisomers. Yield: 7.2 g (60%).
EXAMPLE 17C
7-(3-Hydroxypropyl)-2,2-dimethyl-1,3-dioxolo[4,5g]quinoxaline-6-carboxylic acid 1.1-dimethylethyl ester
The mixture of isomers from Example 17B (3.82 g; 9.5 mmol) was dissolved in dry methanol (270 ml) and hydrogenated for 12 minutes (monitored by tlc) in the presence of palladium (10%) on carbon (2 g). After removal of the catalyst by filtration and evaporation of the filtrate in vacuo an oily residue was obtained (10.4 g) containing ca 70% (by NMR) of the desired 7-(3-Acetyloxy)propyl)-2,2-dimethyl-1,3-dioxolo[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester and ca 30% (by NMR) of a propyl side product. This crude residue was used in the next step without any purification.
To a stirred solution of the so obtained residue (3.62 g) in methanol (100 ml) was added a solution of potassium hydroxide (1.51 g; 27 mmol) in water (7 ml) and stirring was continued at room temperature for 30 minutes. The solvent was removed on a rotary evaporator and the residue was taken up in ethyl acetate and water. The pH of the mixture was brought to 3 by addition of 2N HCl and then the mixture was extracted with ethyl acetate.
The combined organic layers were washed with brine, dried (MgSO 4 ) and evaporated to leave a residue which was chromatographed on silica gel eluting with petroleum ether/ethyl acetate (3:1). The propyl-compund was eluted first (yield: 0.61 g; mp: 91.7°-93.1° C.) then the desired alcohol yield: 0.99 g (30%); mp: 97.6°-98.1° C. (from petroleum ether bp 60°-70° C.). Using only 1 equivalent potassium hydroxide the yield of the desired alcohol can be raised up to 70%. C 19 H 24 N 2 O 5 (360.4)
______________________________________C.sub.19 H.sub.24 N.sub.2 O.sub.5 (360.4)Elemental analysis (%) Calc. Found______________________________________C 63.32 63.04H 6.71 6.74N 7.77 7.85______________________________________
IR(KBr): 1725 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=1.60 (s, 9H); 1.7-2.0 (m, 8H; overlapped by singulett δ=1.77); 3.02 (t, 2H); 3.48 (q(ps), 2 H); 4.57 (t, 1H); 7.32 (s, 1H); 7.37 (s, 1H) ppm.
EXAMPLE 17D
7-[3-[[Bis[(1,1-dimethylethoxy)carbonyl]amino]oxy]propyl]-2,2-dimethyl-1,3-dioxolo[4,5g]-quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
A solution of diethyl azodicarboxylate (0.35 ml; 2.2 mmol) in dry tetrahydrofuran (3 ml) was dropped at room temperature to a mixture of the compound of Example 17D (0.80 g; 2.2 mmol), triphenylphosphine (0.58 g; 2.2 mmol) and Hydroxyimidodicarbonic acid, bis(1,1-dimethylethyl) ester (0.47g; 2.0 mmol) in dry tetrahydrofuran (13 ml) and stirring was continued for 4 to 5 hours at room temperature. The solvent was removed in vacuo and the residue was purified by chromatography on silica gel eluting with petroleum ether/ethyl acetate (gradient 20-30%); yield: 0.55 g (48%); viscous oil.
IR (film): 1792, 1751, 1720 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=1.33 (s, 18H); 1.49 (s, 9H); 1.68 (s, 6H); 1.90 (m c , 2H); 3.00 (t, 2H); 3.89 (t, 2H); 7.20(s, 1H); 7.29 (s, 1H) ppm.
EXAMPLE 17E
3-[3-(Aminooxy)propyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid, hydrochloride
A mixture of the compound of Example 17D (0.50 g; 0.87 mmol) and conc. HCl (5 ml) was heated at 85°-90° C. for 90 minutes. After cooling to 0° C. the precipitate was collected by suction, washed with a few ml conc. HCl and dried in vacuo over P 2 O 5 ; yield: 0.22 g (80%); mp: dec >170° C.; purity by HPLC: 93%.
IR(KBr): 1710 cm -1 ; 1 H-NMR(DMSO-d 6 /trifluoroacetic acid 1:1): δ=2.0-2.35 (m, 2H); 3.43 (t, 2H); 4.14 (t, 2H); 7.51 (s, 1H); 7.56 (s, 1H) ppm.
EXAMPLE 17F
[2R-[2α,3α(Z)]]-3-[3-[[[1-[2-(Formylamino)-4-thiazolyl]-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]propyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid, tetrabutylammonium (1:2) salt
(2R-cis)-3-[[[2-(Formylamino)-4-thiazolyl]oxoacetyl]amino]-2-methyl-4-oxo-1-azetidinesulfonic acid, N,N,N-tributyl-1-butanammonium salt (Example 7) (0.38 g; 0.63 mmol) was dissolved in water (12.5 ml) and the pH of the filtered solution was lowered to 2.0 by the addition of 2N HCl. Then the hydrochloride salt of Example 17E (0.18 g; 0.57 mmol) was added in small portions while the pH of the solution was corrected constantly to 2.0 by addition of a solution of tetrabutylammonium hydroxide in water (40%). Stirring at this pH (2.0) was continued for an additional 4.0 hours, then the pH of the suspension was adjusted to 5.5-6.0 by addition of tetrabutylammonium hydroxide and the nearly clear solution was filtered and freezedried to yield 1.0 g of an orange, crude material which was chromatographed (MPLC) on XAD-2 resin eluting with water-acetonitrile (10-20% gradient). The E-isomer was isolated from the first fractions (yield: 70 mg, 11%) whereas late fractions contained the pure Z-isomer of the title compound yield: 230 mg (36%); Purity=97% by HPLC.
IR(KBr): 1765 cm -1 ; 200 MHz- 1 H-NMR (DMSO): δ=0.92 (t, 24H); 1.17-1.42 (m, 16H) overlapped by 1.28 (d, 3H, J=7 Hz); 1.42-1.65 (m, 16H); 2.05 (m, 2H); 2.93 (t, 2H), J=7 Hz); 3.05-3.25 (m, 16H); 3.98 (quin(ps), 1H, J=7 Hz, J=6 Hz); 4.13 (t, 2H, J=7 Hz); 5.05 (dd, 1H, J=6 Hz, J=9 Hz); 7.02 (s, 1H); 7.06 (s, 1H); 7.37 (s, 1H); 8.48 (s, 1H); 9.65 (d, 1H, J=9 Hz) ppm.
EXAMPLE 17G
[2R-[2α,3α(Z)]]-3-[3-[[[1-(2-Amino-4-thiazolyl-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]propyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid
To a solution of the tetrabutylammonium salt of Example 17F (220 mg, 0.20 mmol) (purity=98% by HPLC) in water (48 ml) was added tetrahydrofuran (14.5 ml) and then the pH of the solution was lowered to 0.6 by the addition of 2N hydrochloride acid (10 ml). The mixture was stirred at room temperature for 72 hours and the precipitated yellowish zwitterion of the compound was collected by suction, washed with a few ml ice-water and dried in vacuo over P 2 O 5 ; yield 80 mg (67%); M.P. dec. >203° C.; purity of 97.0% by HPLC. IR(KBr): 1740 cm -1 ; 1 H-NMR(DMSO-d 6 -trifluoroacetic acid): δ=1.22 (d, 3H, J=7 Hz); 2.17 (quintett (ps), 2H); 3.21 (t, 2H); 4.04 (quintett (ps), 1H, J=7 Hz, J"=6 Hz); 4.28 (t, 2H); 5.08 (d, 1H, J'=6 Hz); 6.97 (s, 1H); 7.26(s, 1H); 7.32 (s, 1H); ppm.
EXAMPLE 18
[2R-[2α,3α(Z)]]-3-[4-[[[1-(2-Amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]butyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid
EXAMPLE 18A
(E)-7-[4-(Acetyloxy)-1-butenyl]-2,2-dimethyl-1,3-dioxolo[4,5g]-quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
A solution (2.5M) of n-butyllithium (12 ml; 30.0 mmol) in hexane was treated dropwise with a solution of diisopropylamine (4.2 ml; 30.0 mmol) in dry tetrahydrofuran (50 ml) with stirring at -5° C. The mixture was held at 0° C. for 30 minutes, and then cooled to -30° C. A solution of the phosphonate of Example 15A was added dropwise and after being stirred at -30° C. for a further 30 minutes a solution of 3-Acetyloxy-propanal prepared accordingly to a literature procedure: Hofstraat, R. G., Lange, J., Scheeren, H. W. and Nivard, R. J. F., J. Chem. Soc. Perkin Trans 1, 1988, 2315, (3.48 g; 30.0 mmol) in dry tetrahydrofuran (70 ml) was added slowly. The mixture was allowed to come to ambient temperature and stirring was continued for an additional 2 hours at this temperature. The solvent was removed on a rotary evaporator and the residue was taken up in ethyl acetate and water and the pH was adjusted to 3 by the addition of 2N HCl. The organic layer was separated, washed with brine, and dried (MgSO 4 ). After removal of the solvent in vacuo the oily residue (15.9 g) was purified by chromatography on silica gel eluting with ethyl acetate/petroleum ether (1:3) to give the title compound as a mixture of stereoisomers (E/Z). Yield: 6.5 g (52.6%).
Stirring off the mixture of stereoisomers (E/Z) with petroleum ether afforded the pure crystalline E-isomer, yield: 4.02 g (34%); mp: 90.7°-91.2° C. C 22 H 26 N 2 O 6 (414.5)
______________________________________C.sub.22 H.sub.26 N.sub.2 O.sub.6 (414.5)Elemental analysis (%) Calc. Found______________________________________C 63.76 63.11H 6.32 6.39N 6.76 6.71______________________________________
IR(KBr): 1735, 1722 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=1.60 (s, 9H); 1.78 (s, 6H); 2.01 (s, 3H); 2.62 (q, 2H; J=6 Hz, J'=6 Hz); 4.19 (t, 2H, J=6 Hz); 6.82 (d, 1H, J"=16 Hz); 7.03 (dd, 1H, J'=6 Hz; J"=16 Hz); 7.30 (s, 1H); 7.38 (s, 1H) ppm.
EXAMPLE 18B
7-[4-Acetyloxy)]butyl]-2,2-dimethyl-1,3-dioxolo[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
The E-isomer from Example 18A (3.60 g; 8.7 mmol) was dissolved in dry methanol (70 ml) and hydrogenated for 4 minutes (monitored by tlc) in the presence of palladium (10%) on carbon (0.5 g). After removal of the catalyst by filtration and evaporation of the filtrate in vacuo an oily residue was obtained containing the acetate and a trace of a butyl side product. This crude residue was used in the next step without any purification. Yield 3.58 g (99%).
EXAMPLE 18C
7-(4-Hydroxybutyl)-2,2-dimethyl-1,3-dioxolo[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
To a stirred solution of the so obtained residue of Example 18B (3.54 g; 8.5 mmol) in methanol (95 ml) was added a solution of potassium hydroxide (0.52 g; 9.35 mmol) in water (6.5 ml) and stirring was continued at room temperature for 25 minutes. The solvent was removed on a rotary evaporator and the residue was taken up in ethyl acetate and water. The pH of the mixture was brought to 3 by addtion of 2N HCl and then the mixture was extracted with ethyl acetate. The combined organic layers were washed with brine, dried (MgSO 4 ) and evaporated to leave a residue which was chromatographed on silica eluting with petroleum ether/ethyl (acetate (3:1). A trace of the butyl compound was eluated first then the desired alcohol, yield: 2.94 g (92.5%).
Alternate method for preparing the title compound of Example 18C
EXAMPLE 18D
7-Formyl-2,2-dimethyl-1,3-dioxolo]4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
Under argon the bromide of Example 3 (3.95, 10.0 mmol) was added to a solution of silver tetrafluoroborate (2.14 g; 11.0 mmol) in dry dimethyl sulfoxide (100 ml) and the mixture was stirred overnight at room temperature. After the addition of N,N-diisopropylethylamine (2.6 ml; 15.0 mmol) stirring was continued at room temperature for 24 hours and then the mixture was poured in ice-water (500 ml). The solution was extracted twice with ethyl acetate and the combined organic layers were washed with brine, dried (MgSO 4 ) and evaporated in vacuo to leave a residue (3.5 g) which separated yellowish needles when treated with few ml ethyl acetate/toluene (1:3). Yield: 1.30g (39%); mp: sint. 193° C., 194°-195° C. dec.
Chromatography of the mother liquor on silica gel eluting with ethyl acetate/toluene (1:3) afforded an additional quantity of the desired title compound (0.65g) besides the corresponding alcohol. Overall yield of the aldehyde title compound 1.95 g (59%). C 17 H 18 N 2 O 5
______________________________________C.sub.17 H.sub.18 N.sub.2 O.sub.5 Calc. (%) Found (%)______________________________________C 61.81 61.80H 5.49 5.54N 8.48 8.50______________________________________
IR(KBr): 1735, 1705 cm -1 ; 100 MHz- 1 H-NMR(DMSO-d 6 ): δ=1.61 (s, 9H); 1.84 (s, 6H); 7.60 (s, 1H); 7.62 (s, 1H); 10.15 (s, 1H) ppm.
EXAMPLE 18E
2.2-Dimethyl-7-[4-(phenylmethoxy)-1-butenyl]-1.3-dioxolo[4,5g]quinoxaline-carboxylic acid, 1,1-dimethylethyl ester
To a stirred suspension of 3-(Benzyloxy)propyl)-propyl)-triphenylphosphonium bromide prepared accordingly to the literature procedure: F. E. Ziegler, I. K. Scott, K. P. Uttam and W. Tein-Fu, J. Amer. Chem. Soc. 107, 2730 (1985) (10.3 g; 21.0 mmol) in dry tetrahydrofuran (500 ml) at 0° C. was added a 2.5M solution of n-butyllithium in hexane (8 ml; 20.0 mmol) over 30 minutes. Then a solution of the compound of Example 18D (6.9 g; 21.0 mmol) in dry tetrahydrofuran (230 ml) was added dropwise over 45 minutes at 0° C. After being stirred for 3 hours at room temperature the reaction mixture was filtered, the filtrate was evaporated in vacuo and the residue was taken up in ethyl acetate and water. The pH of the mixture was brought to 3 by addition of 2N HCl and then the mixture was extracted with ethyl acetate. The combined organic layers were washed with brine, dried (Na 2 SO 4 ) and the solvent was removed on a rotary evaporator. The residue was chromatographed on silica gel eluting with ethyl acetate/toluene (1:3) to yield the desired olefin title compound as a mixture of stereoisomers (E/Z); yield: 6.28 g (68%); oil.
EXAMPLE 18F
7-(4-Hydroxybutyl)-2,2-dimethyl-1,3-dioxolo[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
The olefin of Example 18E (mixture of stereoisomers) (3.01 g; 6.5 mmol) was dissolved in dry methanol (40 ml ) and hydrogenated for 15 minutes (monitored by tlc) in the presence of palladium (10% ) on carbon (0.5 g). After removal of the catalyst by filtration and evaporation of the filtrate in vacuo an oily residue of the still benzyl protected title compound was obtained which was used in the next step without any further purification Yield: 2.6 g (87%).
The crude benzyl-compound of above (2.53 g; 5.4 mmol) was dissolved in dry dimethyl formamide (30 ml) and then hydrogenated for 4 minutes in the presence of palladium (10%) on carbon (0.4 g). After the usual work-up the residue was chromatographed on silica gel eluting with petroleum ether/ethyl acetate (gradient) to afford recovered benzyl compound and the desired title compound. Rehydrogenation of the recovered benzyl-compound afforded after chromatographic purification the desired alcohol in an overall yield of 81% mp: 80.5°-81.5° C. (from ether/petroleum ether). C 20 H 26 N 2 O 5 (374.4)
______________________________________C.sub.20 H.sub.26 N.sub.2 O.sub.5 (374.4)Elemental analysis (%) Calc. Found______________________________________C 64.15 64.04H 7.00 6.99N 7.48 7.48______________________________________
IR(KBr): 3350 cm -1 (OH); 1727 cm -` (CO); 1 H-NMR(DMSO-d 6 ): δ=1.3-1.9 (m, 4H; overlapped by 1.58 (s, 9H) and 1.76 (s, 6H); 2.98 (t, 2H; J=7 Hz); 3.40 (q(ps), 2H; J'=7 Hz); 4.40 (t, 1H; J"=7 Hz); 7.32 (s, 1H); 7.38 (s, 1H) ppm.
EXAMPLE 18G
7-[4-[[Bis[(1-dimethylethoxy)carbonyl]amino]oxy]butyl]-2,2-dimethyl-1,3-dioxolo-[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
A solution of diethyl azodicarboxylate (1.62 ml; 10.3 mmol) in dry tetrahydrofuran (15 ml) was dropped at room temperature to a mixture of the compound of Example 18C or 18F (3.85 g; 10.3 mmol), triphenylphosphine (2.70 g; 10.3 mmol) and the title compound of Example 6 (2.19 g; 9.4 mmol) in dry tetrahydrofuran (70 ml ) and stirring was continued for 3.5 hours at room temperature. The solvent was removed in vacuo and the residue was purified by chromatography on silica gel eluting with petroleum ether/ethyl acetate (gradient 20-30%); yield 4.32 g (71%), viscous oil.
IR (film): 1792, 1751, 1720 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=1.43 (s, 18H); 1.50-1.95 (m, 4H) overlapped by 1.49 (s, 9H) and 1.76 (s, 6H)) 3.01 (t, 2H); 3.87 (t, 2H); 7.31 (s, 1H); 7.39 (s, 1H) ppm.
EXAMPLE 18H
3-[4-(Aminooxy)butyl]6,7-dihydroxy-2-quinoxaline-2-carboxylic acid, hydrochloride
In a simple vacuum distillation apparatus a mixture of the compound of Example 18G (2.68 g; 4.54 mmol) and conc. HCl (100 ml) was heated at 85°-90° C. and ca 700 mbar to distill off the generated acetone. After 2 hours the mixture was evaporated in vacuo to leave a yellow solid which was dissolved in few ml water and then freeze dried (1.78 g; purity=88.2% by HPLC). Rehydrolysis of this material with conc. HCl (70 ml) using similar conditions (80°-85°; 600 mbar) did not improve the purity of the desired compound. Yield: 1.58 g (quant.); purity=76.7 % (by HPLC). This material was used in the next step without any additional purification.
IR(KBr): 1750 cm -1 ; 1 H-NMR(DMSO-d 6 /TFA 1:1): δ=1.7(m c , 4H); 3.35(m c , 2H); 4.05(m c , 2H); 6.96 (s, 1H); 7.56(s, 1H) ppm.
EXAMPLE 18I
[2R-[2α,3α(Z)]]-3-[4-[[[1-[2-(Formylamino)-4-thiazolyl]-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]]amino]oxy]butyl]-6,7 -dihydroxy-2-quinoxalinecarboxylic acids, tetrabutylammonium (1:2) salt
(2R-cis)-3-[[[2-(Formylamino)-4-thiazolyl]oxoacetyl]amino]-2-methyl-4-oxo-1-azetidinesulfonic acid, N,N,N-tributyl-1-butanamminium salt (Example 7) (1.21 g; 2.0 mmol) was dissolved in water (40 ml) and the pH of the filtered solution was lowered to 2.0 by the addition of tetrabutylammonium hydrogen sulfate (0.17 g). Then the hydrochloride salt of Example 18H (0.82 g; ca 2.0 mmol; purity by HPLC: 77%) was added in small portions while the pH of the solution was corrected constantly to 2.0 by addition of a solution of tetrabutylammonium hydroxide (TBA-OH) water (20%). Stirring at this pH (2.0) was continued for an additional 3.0 hours, then the pH of the suspension was adjusted to 5.8 by addition of tetrabutylammonium hydroxide and the solution was freeze-dried to yield 4.66 g of an orange, crude material which was chromatographed (MPLC) on XAD-2 resin eluting with water-acetonitrile (15%). Freeze-drying of the appropriate fractions yielded 0.43 g (19%) of a material with a purity (by HPLC) of 77-86% and 0.51 g (22.8%) of an additional crop with a purity by HPLC) of 95.4-97.4%; overall yield: ca 37%; mp: 97° sint, dec. > 100° C.
IR(KBr): 1762 cm -1 ; 200 MHz- 1 H-NMR(DMSO-d 6 ): δ=0.90 (t, 24 H); 1.10-1.40 (m, 16H) overlapped by 1.28 (d, 3H, J=7 Hz); 1.40-1.85 (m, 20H); 2.88 (t, 2H); J"=7 Hz); 3.25 (m, 16H); 3.97 (quin(ps), 1H, J=7 Hz, J'=6 Hz); 4.27 (t, 2H, J"=7 Hz); 5.06 (dd, 1H, J'=6 Hz; J"'=9 Hz); 7.01 (s, 1H); 7.15 (s, 1H); 7.32 (s, 1H); 8.48 (s, 1H); 9.46 (d, 1H; J"'=9 Hz) ppm.
EXAMPLE 18J
[2R-[2α,3α(Z)]]-3-[4-[[[1-(2-Amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino-[-2-oxoethylidene]amino]oxy]butyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid
To a solution of the tetrabutylammonium salt of Example 18I (336 mg, 0.3 mmol) purity=97.4% by HPLC) in water (75 ml) was added tetrahydrofuran (25 ml) and then the pH of the solution was lowered to 0.6 by the addition of 2N hydrochloride acid (16 ml). The mixture was stirred at room temperature for 70 hours and the precipitated yellowish zwitterion title compound was collected by suction, washed with few ml ice-water and dried in vacuo over P 2 O 5 . Yield 160 mg (87.4%); mp: dec >217° C.; purity 98.8% (by HPLC). C 22 H 23 N 7 O 10 S 2 .2.6 H 2 O
______________________________________C.sub.22 H.sub.23 N.sub.7 O.sub.10 S.sub.2.2.6 H.sub.2 O Calc. Found______________________________________C 40.25 40.01H 4.33 4.28N 14.94 15.00______________________________________ p IR(KBr): 1745 cm.sup.-1 ; .sup.1 H-NMR(DMSO-d.sub.6 -TFA): δ=1.18 (d, 3H, J=7 Hz); 1.80 (m.sub.c, 4H); 3.30 (t, 2H); 4.05 (quintett(ps), 1H, J=7 Hz, J"=6 Hz); 4.20 (, 2H); 5.07 (d, 1H, J=6 Hz); 6.89 (s, 1H); 7.40 (s, 1H); 7.48 (s, 1H) ppm.
EXAMPLE 19
Alternate Preparation of [2R-[2α,3α(Z)]]-3-[4-[[[1-(2-Amino-4-thiazoly)-2)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]butyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid
The compound of Example 17B (2S-cis)-3-[[[(2-Amino-4-thiazolyl)-oxoacetyl]amino]-2-methyl-4-oxo-1-azetidine-sulfonic acid (0.50 g, 1.5 mmol) was suspended in water (30 ml) and the pH was adjusted to 5.5-6.0 by addition of a solution of tetrabutylammonium hydroxide in water (20%) to obtain a clear solution. The pH of this solution was lowered to 2.0 by the addition of tetrabutylammonium hydrogen sulfate (0.14 g). Then the hydrochloride of Example 18H 3-[4-(Aminooxy)butyl]-6,7-dihydroxy-2-quinoxaline-2-carboxylic acid, monohydrochloride (0.62 g; ca 1.5 mmol); purity by HPLC; 77%) was added in small portions while the pH of the soltuion was corrected constantly to 2.0 by addition of a solution of tertrabutylammonium hydroxide in water (20%). Stirring at this pH (2.0) was continued for additional 3.0 hours, then the pH of the suspension was adjusted to 5.8 by addition of tertrabutylammonium hydroxide and the solution was freeze-dried to yield 3.12 g of an orange, crude material which was chromatographed (MPLC) on XAD-2 resin eluting with water-acetonitrile (12%). Freeze-drying of the appropriate fractions yielded 0.11 g (6.7%) of the di-TBA-salt from which the title compound was obtained by dissolving in water (10 ml) and precipitation at pH 2.0 (addition of 2N HCl). Yield: 30 mg (4%);mp: dec. 198° C.
EXAMPLE 20
Alternate Preparation of [2R-[2α,3α(Z)]]-3-[[[[1-(2-Amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]methyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid
EXAMPLE 20A
6,6-Dimethyl[1,3]dioxolo[4,5-f]-2,1,3-benzoxadiazole, 1-oxide
133 g of 2,2-Dimethyl-5,6-dinitro-1,3-benzodioxole was dissolved in 1200 ml dimethylsulfoxide and 39.9 g sodium azide was added and the mixture was stirred at 85°-90° C. for 4 hours. After cooling down to room temperature, the dark solution was poured into 3 L ice water. A precipitate of the title compound was immediately formed. It was isolated by filtration, washed with ice water, redissolved in ethyl acetate (5 L) and dried over Na 2 SO 4 . After removal of the solvent in vacuo 115.7 g of title compound were recovered as yellow needles. M.P. 185°-187° C.
1 H-NMR(DMSO-d 6 ) δ=1.71 (s, 6H); 6.79 (s, 1H); 7.04 (s, 1H) ppm.
EXAMPLE 20B
2,2,7-Trimethyl-1,3-dioxolo[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester, 5,8-dioxide
To 32 g of the compound of Example 20A and 4.75 g of tert-butyl acetoacetate in 750 ml ethanol were added slowly 155 ml of a 1N solution of NaOH (solid) in ethanol (abs.). The temperature of the reaction mixture rose from room temperature to ˜40° C. After complete addition of the NaOH the temperature was kept at 50°-60° C. with heating for 45 minutes. A yellow precipitate was formed. After cooling with ice the precipitate was isolated by filtration and washed with ice water. Drying over P 2 O 5 gave pure title compound 43.6 g yellow needles.
M.P. 205°-207° C. (from toluene). 1 H-NMR(DMSO-d 6 ): δ=1.55 (s, 9H); 1.76 (s, 6H); 2.31 (s, 3H); 7.65 (s, 1H); 7.73 (s, 1H) ppm. IR(KBr): 1740 cm -1 (COO+).
EXAMPLE 20C
7-[(Trifluoroacetyloxy)methyl]-2,2-dimethyl-1,3-dioxolo-[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethyl ethyl ester, 5-oxide
To 20 g of the compound of Example 20B suspended in 60 ml dichloromethane was added at -20° C. a solution of 100 ml trifluoroacetic acid anhydride in 40 ml dichloromethane. While stirring, an orange colored solution was obtained after 30 minutes. The solution was then stirred at 0° C. for one hour. The color turned to a dark green. The solvent, excess trifluoroacetic acidanhydride and formed trifluoroacetic acid was then distilled of in vacuo at room temperature. After evaporation with an oil-vacuo for additional one hour a beige foam was obtained. This was stirred with 150 ml ether and cooled to -20° C. A dark red suspension was obtained. After filtration and washing with ether and hexane the title compound was obtained as a beige solid (20.4 g). The compound is unstable and must be immediately used for further transformation.
EXAMPLE 20D
7-(Bromomethyl)-2,2-dimethyl-1,3-dioxolo-[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester, 5-oxide
16 g of crude 7-[(Trifluoroacetyloxy)methyl]-2,2-dimethyl-1,3-dioxolo-[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethyl ethyl ester, 5-oxide and 7 g lithium bromide was stirred at 50° C. for 3 hours in 750 ml acetone. After continued stirring at room temperature overnight, the solvent was distilled off and the residue suspended in toluene/ethyl acetate (6:1) and after filtration the filtrate passed through a column with 500 g silica gel. Toluene/ethyl acetate (6:1) as an eluent. From the relevant fractions 14.7 g pure title compound was obtained after evaporation as a white crystalline solid.
M.P.=196°-198° . IR(KBr): 1735 cm -1 (COO+) 1 H-NMR(DMSO-d 6 ): δ=1.62 (s, 9H); 1.77 (s, 6H); 4.60 (s, 2H); 7.21 (s, 1H); 7.77 (s, 1H) ppm.
EXAMPLE 20E
7-[[[Bis[(1,1-dimethylethoxy)carbonyl]amino]oxy]methyl]-2,2-dimethyl-1,3-dioxolo[4,5g]-quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester, 5-oxide
A mixture of the title compound of Example 20D (2.05 g) , and the title compound of Example 6 (1.4 g) and potassium carbonate (powder) (7.1 g) and acetone (100 ml) was stirred for 3 hours at room temperature. The solvent was distilled off and the residue was taken up in a mixture of water and ethyl acetate. The washed organic phase was concentrated and purified by chromatography on silica gel eluting with toluene/ethyl acetate (3:1). Fractions containing the title compound were collected and evaporated. Yield 2.60 g; m.p.=122°-124° C. (light yellowish solid).
1 H-NMR(DMSO-d 6 ): δ=1.29 (s, 18H); 1.50 (s, 9H); 1.81 (s, 6H); 4.93 (s, 2H); 7.40 (s, 1H) ppm.
EXAMPLE 20F
7-[(Aminooxy)methyl]-2,2-dimethyl- 1,3-dioxolo-[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester, hydrobromide
The title compound of Example 20E (0.563 g) was dissolved in dry dichloromethane (20 ml) and at -70° C. boron tribromide (2 ml) was added. Stirring was continued for 2 hours at -70° C. and at room temperature overnight. After evaporation in vacuo the brown honey like residue was dissolved in 25 ml ethyl acetate/methanol at -80° C., stirred for 10 minutes and again evaporated. The residue was stirred with warm n-hexane. The yellow solid was used in the next step without further purification. Yield: 0.32 g.
EXAMPLE 20G
3-[(Aminooxy)methyl]-6,7-dihydroxy-2-quinoxaline-6-carboxylic acid, hydrochloride
The compound from Example 20F (0.3 g) was stirred with hydrochloric acid conc. (3 ml) at 65°-70° C. for 1 hour. A yellow precipitate of the title compound was formed. It was isolated by filtration and dried over P 2 O 5 in vacuo for 8 hours. Yield: 0.25 g.
EXAMPLE 20H
Alternate method for preparing the title compound of Example 11 [2R-[2α,3α(Z)]]-3-[[[[1-(2-Formylamino-4-thiazolyl) -2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]methyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid, tetrabutylammonium salt (1:2)
2.1 g of (2R-cis)-3-[[[2-(Formylamino)-4-thiazolyl]-oxoacetyl]amino]-2-methyl-4-oxo-1-azetidine-sulfonic acid, N,N,N-tributyl-1-butanammonium salt (Example 7) were stirred in 80 ml water until complete solution (˜1 h). 0.55 g tetrabutylammoniumhydrogensulfate were added and the pH of the solution was adjusted to DH 2.0 (1n HCL). 1.2 g of the compound of Example 9 were divided in 6 portions. Every 20 minutes one portion was added slowly to the solution and after each addition the pH was readjusted to 2.0 (TBA + OH - ). The reaction solution was stirred for two additinal hours after the last addition of the compound of Example 9 and the pH was controlled every 20 minutes and readjusted to 2.0 if necessary. The reaction was stopped by adjusting the pH to 6.5 (TBA + OH 31 ) and the remaining solution freeze dried. 12-13 g solid material of the crude title compound was obtained which was purified by column chromatography.
EXAMPLE 20I
[2R-[2α,3α(Z)]]-3-[[[[1-(2-Amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]methyl]-6,7-dihydroxy-2-quinoxaline-carboxylic acid
8.7 of the purified compound of Example 20H freeze-dried material were stirred for one hour in 400 ml ethyl acetate to get a uniform crystalline material. This material was dissolved in 1 L water and 470 tetrahydrofuran and stirred to complete solution. The pH was then adjusted to 0.5 with concentrated hydrochloric acid and the solution stirred for 3 days at room temperature. After ˜8 hours crystals of the title compound were formed. On the third day the formed title compound was isolated by filtration and washed with tetrahydrofuran/water (1:10) containing a few drops of 1n hydrochloric acid. After drying over P 2 O 5 in vacuo a solid mass of title compound was obtained. This was stirred with 100 ml tetrahydrofuran containing 3 drops water for one hour. After filtration 4.2 g of the title compound light yellowish needles were obtained (drying over silica gel for 6 hours). Purity 99.5% (by HPLC)
M.P. dec >208° C.
EXAMPLE 21
Alternate Method for Preparing 2,2,7-Trimethyl-1,3-dioxolo[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester
To 38 g of the compound of Example 20B dissolved in 100 ml CHCl 3 (abs.) was added 75 g PCl 3 dropwise. During adding, the temperature rose to 40° C. (about 40 minutes). Stirring was then continued overnight at room temperature. Formed POCl 3 , solvent and excess PCl 3 were then distilled off in vacuo. The oily residue was dissolved in 250 ml ethyl acetate and stirred with ice water for 30 minutes while the pH was adjusted with sodium bicarbonate between 6-7. The separated organic phase was then washed with water, dried and the solvent distilled off. 33 g pure title compound was obtained as white crystal solid.
EXAMPLE 22
Alternate Preparation of 2,2,7-Trimethyl-1,3-dioxolo[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester, 5,8-dioxide
To a solution of 2,2,7-Trimethyl-1,3-dioxolo[4,5g]quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester (1.26g, 4.0 mmol) in 20 ml chloroform was added 2.53 g (8.8 mmol) m-chloroperoxybenzoic acid. After stirring overnight at room temperature a solid was filtered off and the solvent was distilled off in vacuo. The residue was partitioned between water and ethyl acetate. The phases were separated and the organic phase washed with saturated sodium hydrogencarbonate solution and with brine. After drying over sodium sulfate and evaporation 1.41 (quant.) of a mixture of the title compound and 2,2,7-Trimethyl-1,3-dioxolo-[4,5g]-quinoxaline-6-carboxylic acid, 1-dimethyl ester, 8-oxide was obtained. The mixture was chromatographed on silica gel with ethyl acetate/petroleum ether 1:2 as eluent to give 0.41 g (30.8%) mono-N-oxide and 0.82 g (58.9%) di-N-oxide. M.P.: 181.9° C.
IR(KBr): 1735 cm -1 (CO) 1 H-NMR(DMSO-d 6 ): δ=1.59 (s, 9H); 1.80 (s, 6H); 2.40 (s, 3H); 7.68 (s, 1H); 7.73 (s, 1H); ppm Using the procedure above with four equivalents of MCPBA afforded the di-N-oxide in 70% yield.
EXAMPLE 23
7-Bromomethyl-2,2-dimethyl-1,3-dioxolo-[4,5g]-quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester, 5,8,-dioxide
To a solution of the title compound of Example 22 (3.48 g, 10.0 mmol) in 20 ml carbon tetrachloride were added 1.78 g (10.0 mmol) N-bromo succinimide. The mixture was heated to reflux and 10 portions of catalytical amounts of azobisisobutyronitrile were added within 8 hours. The mixture was heated overnight and after cooling the solid filtered off with suction. The filtrate was evaporated and the residue (3.7 g, 87%) chromatographed on silica gel with ethyl acetate/petroleum ether 1:1 as eluent to give 1.87 g (43.6%) of the title compound.
M.P.: 150.9° C. IR(KBr): 1740 cm -1 (CO) 1 H-NMR(DMSO-d 6 ): δ=1.60 (s, 9H); 1.81 (s, 6H); 4.62 (s, 2H); 7.73 (s, 1H); 7.79 (s, 1H); ppm.
EXAMPLE 24
7-[[[Bis[1,1-dimethylethoxy)carbonyl]amino]oxy]methyl]-2,2-dimethyl-1,3-dioxolo[4,5g]-quinoxaline-6-carboxylic acid, 1,1-dimethylethyl ester, 5,8-dioxide
To a solution of the title compound of Example 23 (1.81 g, 4.25 mmol) in 30 ml acetone were added 2.35 g (17.0 mmol) potassium carbonate, the title compound of Example 6 (0.97g, 4.16 mmol) and a catalytical amount of sodium iodide. The mixture was stirred for 60 hours at room temperature. The resulting solid was filtered off with suction, washed with acetone, dissolved in ethyl acetate and washed with water, dil. citric acid and again water. After drying and evaporation of the solvent the residue was dissolved in 10 ml ether and an equal amount of petroleum ether was added. After one night in the refrigerator the resulting precipitate was filtered off, washed with petroleum ether and dried to give 2.1 g (85.1%) of the title compound.
M.P.: 75.5° C. IR(KBr): 1740, 1790 cm -1 (CO) 1 H-NMR(DMSO-d 6 ): δ=1.29 (s, 18H), 1.55 (s, 9H); 1.81 (s, 6H); 5.06 (s, 2H); 7.78 (s, 1H); 7.80 (s, 1H); ppm.
EXAMPLE 25
5,6-Bis(phenylmethoxy)benzofurazan, 1-oxide
To a solution of 4,5-dibenzyloxy-1,2-dinitrobenzene, (1.9 g, 5.0 mmol) in 25 ml dimethylsulfoxide were added 1.16 g (17.8 mmol) sodium azide and the mixture was stirred at 85° C. for 4 hours. The mixture was then poured into water and the resulting precipitate filtered off with suction, washed with water and dried in vacuo. Yield of title compound 1.49 g (85.5%)
M.P.: 206°-208° C. (dec.) 1 H-NMR(DMSO-d 6 : δ=5.28 (s, 4H), 7.2-7.6 (m, 12H); ppm.
EXAMPLE 26
3-Methyl-6,7-bis(phenylmethoxy)-2-quinoxaline-carboxylic acid, ethyl ester, 1,4-dioxide
To a suspension of the title compound of Example 25 (1.04 g, 3.0 mmol) in 20 ml ethanol were added at 60° C. ethyl acetoacetate (0.78 g, 6.0 mmol) and sodium hydroxide (0.12 g, 3.0 mmol ) in 4 ml ethanol. The mixture was stirred at 60° C. for 8 hours and another 10 hours at room temperature. The resulting precipitate was filtered off with suction, washed with water and dried in vacuo to give 0.62 g of crude product. The crude material was chromatographed on silical gel with ethyl acetate/petroleum ether 2:1 as eluent and yielded 0.38 g (27.5 %) of the title compound.
M.P.: 175°-177° C. (dec.) IR(KBr): 1740 cm -1 (CO) 1 H-NMR(DMSO-d 6 ): δ=1.34 (t,3H); 2.40 (s, 3H); 4.48 (q, 2H); 5.42 (s, 4H); 7.3-7.6 (m, 10H); 7.82 (s, 1H); 7.91 (s, 1H); ppm.
EXAMPLE 27
3-Methyl-6,7-bis(phenylmethoxy)quinoxaline-2-carboxylic acid
EXAMPLE 27A
3-Methyl-6,7-bis(phenylmethoxy)quinoxaline-2-carboxylic acid, phenylmethyl ester
The compound from Example 2 (6.3 g; 20.0 mmol) was treated with concentrated hydrochloric acid (170 ml) at 75° C. for 90 minutes and the formed precipitate was collected from the cold suspension by suction. After drying in vacuo over P 2 O 5 and subsequent washing with acetonitrile, ether and n-pentane, this crude hydrochloride salt (4.0g; mp 201°-202° C.) was suspended in dry dimethylformamide (50 ml) and then potassium carbonate (12.4 g; 0.09 mol) was added slowly (evolution of CO 2 ) followed by the addition of benzylbromide (15.4 g; 0.09 mol). After being stirred at 75° C. for 4 hours the mixture was cooled, filtered and the filtrate was evaporated in vacuo. The resulting residue was washed with few ml ether and then taken up in ethyl acetate and water and the pH of the mixture was adjusted to 2 by the addition of diluted hydrochloric acid. The organic layer was separated, washed with water and brine, dried (Na 2 SO 4 ) and evaporated in vacuo to leave a residue which was crystallized from ethylacetate and petroleum ether, yield: 3.8 g (39%) mp 137°-139° C.
IR(KBr): 1715, 1703 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=2.78 (s, 3H); 3.33 (s, 2H); 5.37 (s, 2H); 5.43 (s, 2H); 7.25-7.65 (m, 17H) ppm.
EXAMPLE 27B
3-Methyl-6,7-bis(phenylmethoxy)quinoxaline-2-carboxylic acid
The compound of Example 27A (4.9 g, 10.0 mmol) was added to a solution of potassium hydroxide (2.2 g, 40.0 mmol) in ethanol/water (80 ml/16 ml) and the mixture was stirred at 80° C. for 20 hours and then cooled (5° C.). The precipitate was collected by suction, washed with ether (4.3 g) and then suspended in water (100 ml). After correction of the pH of this suspension to 2 by the addition of 2N HCl stirring was continued at room temperature for 20 minutes and the crystallized title compound was isolated by suction, washed with water and dried in vacuo over P 2 O 5 . Yield: 3.4 g (85%); mp 198°-200° C. C 24 H 20 N 2 O 4 0.1 H 2
______________________________________C.sub.24 H.sub.20 N.sub.2 O.sub.4.0.1 H.sub.2 O calc. (%) found (%)______________________________________C 71.67 71.50H 5.06 5.03N 6.96 7.14______________________________________
IR(KBr): 1752, 1717 cm -1 ; 1 H-NMR(DMSO-d 6 ): δ=2.78 (s, 3H); 4.39 (s, 4H); 7.25-7.70 (m, 12H); COOH too broad, not registered.
EXAMPLE 28
4-Bis(phenylmethoxy)-1,2-benzenediamine, triflouroacetate (1:1) salt
EXAMPLE 28A
2,2-Dimethyl-N-[2-nitro-4,5-bis(phenylmethoxy)methoxy)phenyl]propanamide
To a suspension of 2-nitro-4,5-dibenzyloxybenzoic acid (1.89, 5.0 mmol) in 30 ml tert-butanol were added diphenylphosphoryl azide (1.65 g, 6.0 mmol) and triethylamine (0.61 g, 6.0 mmol). The mixture was heated to reflux overnight. After cooling the resulting precipitate was filtered off, washed with ether and dried in vacuo.
Yield of title compound: 1.74 g (84%) m.p.: 145°-149° C. IR(KBr): 1715 cm -1 (CO). 1 H-NMR(DMSO-d 6 ): δ=1.47 (s, 9H); 5.19 (s,2H); 5.22 (s, 2H); 7.40 (mc, 10H); 7.70 (s, 1H); 7.73 (s, 1H); 9.65 (s, 1H); ppm.
EXAMPLE 28B
N-[2-Amino-4,5-bis(phenylmethoxy)phenyl]-2,2-dimethylpropanamide
Under nitrogen, the title compound of Example 28A (15.77 g, 35.0 mmol) was dissolved in 350 ml dimethylformamide. 500 mg platinum (IV) oxide were added, the mixture was heated to 60° C. and hydrogenated by monitoring with thin layer chromatography until the end of the reaction (1-5 days). The hydrogen was replaced with nitrogen, the catalyst was filtered off and the filtrate evaporated (all operations under nitrogen, otherwise the product has a deep blue color). The residue was triturated with degassed water to remove residual dimethylformamide.
Yield after drying of title compound: 14.1 g (96%) m.p. 115° C. IR(KBr): 1680 cm -1 (CO). 1 H-NMR(DMSO-d 6 ): δ=1.45 (s, 1H); 4.60 (s, broad, 2H); 4.91 (s, 2H); 5.00 (s, 2H); 6.50 (s, 1H); 6.94 (s, 1H); 7.40 (mc, 10H); 8.20 (s, 1H);ppm.
EXAMPLE 28C
4-Bis(phenylmethoxy)-1,2-benzenediamine, trifluoroacetate (1:1) salt
A mixture of the title compound of Example 28B (1.0 g, 2.38 mmol) and 20 ml of trifluoroacetic acid was stirred at 0° C. for one hour. Trifluoroacetic acid was distilled off and the residue triturated with ether. The title compound was filtered off, washed with water and dried in vacou.
Yield 0.78 g (74%) M.P.: 122.5° C. C 20 H 20 N 2 O 2 . 1:1 CF 3 COOH
______________________________________C.sub.20 H.sub.20 N.sub.2 O.sub.2.1:1 CF.sub.3 COOH Calculated (%) Found (%)______________________________________C 60.31 59.94H 4.82 4.83N 6.37 6.53F 13.60 13.60______________________________________
IR(KBr): 1675cm -1 (CO). 1 H-NMR(DMSO-d 6 ): δ=5.03 (s, 4H); 6.79 (s, 2H); 7.41 (mc, 10 H); ppm.
EXAMPLE 29
3-Methyl-6,7-bis(phenylmethoxy)-2-quinoxalinecarboxylic acid, 1,1-dimethylethyl ester
4,5-Bis(phenylmethoxy)-1,2-benzenediamine, trifluoroacetate (1:1) salt (5.48 g, 12.62 mmol) was dissolved in 45 ml water/tetrahydrofuran (2:1) and the pH was brought to 5 with 2N sodium hydroxide solution. t-Butyl 2,3-dioxobutynate (3.44 g, 20.0 mmol) was added and the mixture was heated to reflux for 80 minutes. Tetrahydrofuran was distilled off and the residue was extracted with ethyl acetate. The organic phase was washed with water, dried and stirred with activated carbon. After filtration and evaporation a resin was obtained which crystallized. This material was chromatographed on silica gel with ethyl acetate/petroleum ether (1:2) as eluent. The sample containing fractions were collected to give after evaporation and trituration with petroleum ether 3.33 g (58%) of the title compound.
M.P.: 111° C. IR(KBr): 1725 cm -1 (CO). 1 H-NMR(DMSO-d 6 ): δ=1.45 (s, 9H); 2.67 (s, 3H); 5.32 (s, 4H); 7.2-7.6 (m, 12 H); ppm.
EXAMPLE 30
[2R-[2α,3α(Z)]]-3-[[[[1-(2-Amino-4-thiazoly)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]methyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid, L-arginine salt
To 22 gram of the title compound of Example 11 ([2R-[2α,3α(Z)]]-3-[[[[1-(2-amino-4-thiazolyl)-2-[(2-methyl-4-oxo-1-sulfo-3-azetidinyl)amino]-2-oxoethylidene]amino]oxy]methyl]-6,7-dihydroxy-2-quinoxalinecarboxylic acid) activity was added 12.5 grams of L-arginine and the two powders were mixed. The powder blend was added to 180 grams of water with vigorous agitation until the powders were dissolved. The DH of the solution was adjusted to 5.5 with an additional 0.9 grams of L-arginine to the solution. The final batch volume was adjusted to 220 mL with addition of more water. The solution was filtered through a 0.2 micron filter into appropriate containers and freeze dried. The resultant product was a dark yellow to orange cake or fragmented cake. | Antibacterial activity is exhibited by novel compounds having the formula ##STR1## where R 1 , R 2 , and M are as defined herein and X is --(CH 2 ) n -- wherein n is 0, 1, 2, 3 or 4 or CR 3 R 4 wherein R 3 and R 4 are the same or different and each is hydrogen, --CH 3 or --C 2 H 5 or R 3 and R 4 taken together with the carbon atom to which they are attached form a 3, 4, 5, 6 or 7-membered cycloalkyl ring. Also described are various intermediates for the preparation of compounds of formula 1. | 8 |
CROSS-REFERENCE TO PROVISIONAL APPLICATIONS(S)
This application claims the benefit of U.S. Provisional Application No. 60/160,377, filed Oct. 19, 1999.
BACKGROUND OF THE INVENTION
The invention relates to a motor controller and more particularly to a motor controller for driving a fluid impeller and still more particularly to a motor controller for driving a fluid impeller to provide a specific fluid flow rate.
It is known to employ electric motors to drive fluid impellers such as fan blades or blower cages in air moving apparatus. Such apparatus are typically used in heating, ventilation and air conditioning applications.
It is further known that heating, ventilation and air conditioning systems require a constant fluid flow in order to operate efficiently. Fluid resistance in the ducting of such systems typically varies with time as a result of various in fluid paths and duct openings. For example, every adjustment of a ventilation opening causes a fluid resistance change in the ducting.
It is known that blower torque must be adjusted to compensate for variable fluid resistance if constant fluid flow is to be maintained.
Various methods and apparatus are known to adjust blower torque in response to variations in fluid resistance or load. Typically, fluid flow may be measured directly by fluid flow transducers which are immersed in the fluid flow path. An electrical signal is typically fed back from the transducers to a microprocessor system or an electric circuit which is designed to adjust the speed of a blower motor to approach a predetermined constant value. Such systems are often too expensive or comprise components that are too large for use in practical heating, ventilation and air conditioning applications.
It is known that the magnitudes of a phase current in a blower motor drive circuit is related to the magnitude of fluid flow which is impelled by the blower. It is further known to provide a constant fluid flow by comparing a measured phase current of a blower motor drive circuit with an empirically determined ideal reference phase current for a specific constant fluid flow to determine an error phase current signal. The empirically determined reference phase current value is typically stored in a look-up table in the memory of a microprocessor system. It is further known to manipulate an error phase current signal so that it is suitable for input as an index to a pulse width modulator in a motor control circuit wherein the motor control circuit is caused to change motor speed to reduce the error phase current signal. The error phase current signal is reduced as the measured motor current approaches the ideal constant flow reference phase current.
Such methods may provide imprecise flow control because phase currents are known to fluctuate and are typically noisy. Furthermore such methods require added cost because they require current measurement feedback loops.
It is desirable to provide a constant fluid flow motor controller of reduced complexity by means not requiring direct measurement of fluid flow rate or motor current nor requiring any dedicated feedback sensor components.
SUMMARY OF THE INVENTION
Accordingly, the invention provides a specific fluid flow motor controller by employing a theoretically derived algorithm to operate on critical motor parameters internal to a variable frequency drive.
The algorithm of the invention employs an at least second-order polynomial equation, for describing blower torque, as follows:
T b =A 2F N b 2 +A 1F N b +A 0F (1)
wherein T b is the torque required by the blower at speed N b to deliver a specific flow rate and A 2F , A 1F and A 0F are specific blower constants of proportionality for the required flow rate F.
Equation (1) characterizes the steady-state control relationship between the blower speed N b and the required blower torque to deliver the desired rate of fluid flow. The set of constants of proportionality A 2F , A 1F and A 0F are deduced uniquely for each blower design. The size of the constant set for varying F is chosen appropriately to meet the required range of flow control.
The algorithm of the invention further employs another at least second-order polynomial equation for describing motor torque as follows:
T m =B 2R N m 2 +B 1R N m +B 0R (2)
wherein T m is the torque produced by the induction motor at a speed N m while operating with a specific voltage-frequency index R and B 2R , B 1R and B 0R are specific motor constants of proportionality for the voltage-frequency index R.
Equation (2) characterizes the steady control relationship between an induction motor speed N m and the developed motor torque for the operating voltage-frequency index. The set of constants or proportionality B 2R , B 1R and B 0R are deduced uniquely for each induction motor and drive control electronics design to be used. The size of the constant for varying R set is chosen to meet the required fineness of control.
The invention employs a microprocessor system to implement a steady state control algorithm and a transient control algorithm. The transient control algorithm comprises a start-up procedure which controls the motor/blower system until it approaches a steady state condition. Under steady state conditions, T b =T m if N b =N m =N as when the motor is directly attached to the blower. Otherwise, the product of the motor torque-speed equals the product of blower torque speed.
When the control system is started it executes the transient control algorithm for a start-up period. During the start-up period the microprocessor system changes the voltage-frequency index of the controller to cause the motor speed to ramp up from rest or zero rotations per minute to a desired steady state speed. The microprocessor system computes the speed value numerically by manipulating an output signal from a speed sensor in the induction motor/blower system. After the start-up period, the microprocessor system executes the steady state control algorithm. The start-up period is chosen based upon the rotational inertia of the particular motor/blower system so that the speed will reach the desired steady state value before the end of the start up period.
While executing the steady state control algorithm, the microprocessor system calculates the required blower torque T b using equation (1). The microprocessor system reads a user input, typically a selector switch bank, which provides a desired fluid flow rate signal (ie., an input value for F) and selects the matching constants A 2F , A 1F , and A 0F from memory. The microprocessor system computes the motor speed by manipulating the output of the speed sensor. The microprocessor system calculates the required blower torque using equation (1) to operate on the selected flow constants and actual motor speed.
While executing the steady state control algorithm, the microprocessor system also calculates the developed motor torque T m by using equation (2). The motor speed is taken from the speed sensor and the motor constants B 2R , B 1R and B 0R are read from memory as a function of the operating voltage-frequency index.
While executing the steady state algorithm the microprocessor system compares the computed values of T b and T m and adjusts the voltage-frequency index to force T b and T m to converge. If T b =T m the microprocessor system makes no changes to the voltage-frequency index. If T b >T m the microprocessor system modifies the voltage-frequency index to cause T m to increase. If T b <T m the microprocessor system modifies the voltage-frequency index to cause T m to decrease. The microprocessor system waits for a settle time after each modification of the voltage-frequency index wherein the settle time is determined by the motor/blower system rotational inertia. The microprocessor system continuously repeats the steps of the steady state algorithm.
Again, the foregoing assumes the motor speed equals blower speed. The foregoing also that the main supply voltage is constant. However, the algorithm may optionally apply corrections for either, including for supply voltage variation where improved flow control resolution is required.
It is an advantage of the invention to provide a specific fluid flow rate without the need for any motor current sensor or motor current feedback.
BRIEF DESCRIPTION OF THE DRAWINGS
There are shown in the drawings certain exemplary embodiments of the invention as presently preferred. It should be understood that the invention is not limited to the embodiments disclosed as examples, and is capable of variation within the scope of the appended claims. In the drawings, the sole FIGURE is a block diagram view of a motor/blower system having an inverter fed induction motor drive, wherein the motor/blower system utilizes a control algorithm in accordance with the invention which in response to a motor speed sensor input signal provides a voltage-frequency index output signal to a variable frequency motor drive to adjust motor speed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the FIGURE, the specific flow motor controller 10 of the invention comprises means 15 for detecting a signal from a speed sensor in an induction motor 14 in communication with means for signal manipulation 20 , preferably a microprocessor system or digital signal processor, means 18 for producing an electrical signal (“selector means”) to represent a specific fluid flow rate, preferably a switch bank, in communication with the manipulation means, and memory means to store electrical signals which represent a plurality of numeric constant values. The manipulation means is in electrical communication with a variable frequency drive 12 wherein the manipulation means is capable of modifying a voltage frequency index to the variable frequency drive. This changes the speed of the motor 14 which changes the speed of the blower 16 .
The control circuitry (eg., the ‘manipulation means’) preferably comprises a microdevice processing unit such as a microprocessor or micro-controller or the like, or else an integrated product like a digital signal processor. Generally, a microprocessor comprises a general use instruction code execution device. In distinction, a micro-controller is more of a specific use device, perhaps characterized by having a simplified instruction set and being designed to work with smaller address space than other microprocessors. These simplifications plus others that realize various input-output services that would otherwise be realized on separate chips, have the effect of reducing the total parts cost in a micro-controller system, an important consideration if the micro-device is to be designed into a manufactured product for which cost containment is paramount.
Whereas nowadays high-end micro-devices have 32-bit, 64-bit and beyond registers, there remains ample applications for highly economical 8-bit micro-devices, again especially in cases where cost is paramount. Some of the more popular 8-bit microprocessors and micro-controllers include those products of Intel and Motorola such as the Intel 8080 or Motorola's MC6800, MC6805 and/or MC68HC11. An example digital signal processor would include Texas Instrument's popular 16-bit digital signal processor, model no. TMS32024X.
Briefly, the invention involves some of the following highlights. The manipulation means executes program steps which change the voltage-frequency index of the variable frequency drive to cause a motor/blower rotational speed to ramp up from zero rotations per minute to a predetermined steady state speed within a predetermined start-up time. The steady state speed and start-up time are determined according to the rotational inertia of the particular motor/blower system and the required speed range.
An array of specific blower constant values, A 2F , A 1F and A 0F are stored in memory wherein a specific flow rate F serves as an index to reference the proper set of constants from the array. The specific flow rate F is determined by a selection from a selector means of a value for which the selector means provides a corresponding electrical signal. The manipulation means reads an input signal from the speed sensor to determine a motor rotational speed N m which also determines the equal blower rotational speed N b . In a simple case the motor speed equals the blower speed. The manipulation means processes the selected blower constant values A 2F , A 1F and A 0F together with the blower rotational speed to determine the required steady state blower torque T b , as described by at least a second-order polynomial equation as follows:
T b =A 2F N b 2 +A 1F N b +A 0F .
An array of specific motor constant values B 2R , B 1R and B 0R are stored in memory wherein a specific voltage-frequency index R serves as an index to reference the proper set of constants from the array. The manipulation means reads the voltage-frequency index R from the variable frequency drive. The manipulation means processes the appropriate motor constant values B 2R , B 1R and B 0R together with the motor rotational speed N m to determine the steady state motor torque T m as described by another at least a second-order polynomial equation as follows:
T m =B 2R N m 2 +B 1R N m +B 0R .
The manipulation means compares the computed values of T b and T m and adjusts the voltage-frequency index to force T b and T m to converge. If T b =T m the manipulation means makes no changes to the voltage-frequency index. If T b >T m the manipulation means modifies the voltage-frequency index to cause T m to increase. If T b <T m the manipulation means modifies the voltage-frequency index to cause T m to decrease.
The manipulation means waits for a settle time after each modification of the voltage-frequency index wherein the settle time is determined by the motor/blower system rotational inertia. The manipulation means continuously repeats the steps of comparing T b to T m and causing the two results to converge by the modifying the voltage-frequency index.
The foregoing includes assumptions including that motor speed equals blower speed. The following more particularly describes aspects of the invention when that is not necessarily true.
A control apparatus is provided for controlling flow output of an induction motor/blower system. The induction motor/blower system has an induction motor coupled to a blower such that a motor-torque by rotor-speed product (T m ×N m ) of the induction motor substantially corresponds to a blower-torque by impeller-speed product (T b ×N b ) of the blower at steady state and where the ratio of rotor-speed to blower-speed (N m /N b ) is known.
The control apparatus comprises a data processor and a motor drive, operably coupled to the data processor, which adjusts motor speed N m in response to control signals from the data processor corresponding to a voltage-frequency index R.
A device is provided for serving the data processor information corresponding to flow command information F. Another device is provided for serving the data processor information corresponding to one of rotor speed N m or impeller speed N b .
The data processor is operational to achieve the following:
fetch the most recent voltage-frequency index R, the flow command information F, and the known ratio N m /N b from either storage or inputs;
solve for the other of impeller speed N b or rotor speed N m ;
solve for required blower torque T b by a polynomial equation expanded through at least second order terms and such that the blower-torque equation's coefficients vary with the flow command information F according to:
T b =A 0F +A 1F N b +A 2F N b 2 + . . . ,
including extracting the blower-torque equation's coefficients A 0F , A 1F , A 2F . . . , from storage according to the flow command value F;
solve for delivered motor torque T m by another polynomial equation expanded through at least second order terms and such that the motor-torque equation's coefficients vary with the most recent voltage-frequency index R according to:
T m =B 0R +B 1R N m +B 2R N m 2 + . . . ,
including extracting the motor-torque equation's coefficients B 0R , B 1R , B 2 . . . , from storage according to the most recent voltage-frequency index R;
compare, in cases of the ratio N m /N b being substantially unity, the required blower-torque (required-T b ) to the delivered motor-torque (delivered-T m ), otherwise the product of required blower-torque by impeller-speed (required-T b ×N b ) to the product of delivered motor-torque by rotor-speed (delivered-T m ×N m ) and, in any case,
respond to inequality by signaling the motor drive with a succeeding most recent voltage-frequency index R which is modified to adjust the motor speed correspondingly.
The data process is preferably further operational to idle for a pre-determined settling time after the activities of compare and respond (if any response), by repeating all over. The data processor includes optional circuitry incorporating one of a micro-processor, a micro-data processor, or a digital signal processor.
The activity of ‘responding’ as following the activity of ‘comparing,’ in cases of the ratio N m /N b being substantially unity, the required blower-torque (required-T b ) to the delivered motor-torque (delivered-T m ), further comprises:
not modifying the most recent voltage-frequency index R if the required blower-torque (required-T b ) is substantially the same as the delivered motor-torque (delivered-T m );
increasing the most recent voltage-frequency index R by a given increment if the required blower-torque (required-T b ) is not substantially the same as and is greater than the delivered motor-torque (delivered-T m ); and
decreasing the most recent voltage-frequency index R by a given decrement if the required blower-torque (required-T b ) is not substantially the same as and is less than the delivered motor-torque (delivered-T m ).
Alternatively, the activity of ‘responding’ as following the activity of ‘comparing’ the product of required blower-torque by impeller-speed (required-T b ×N b ) to the product of delivered motor-torque by rotor-speed (delivered-T m ×N m ), further comprises:
not modifying the most recent voltage-frequency index R if the product of required blower-torque by impeller-speed (required-T b ×N b ) is substantially the same as the product of delivered motor-torque by rotor-speed (delivered-T m ×N m );
increasing the most recent voltage-frequency index R by a given increment if the product of required blower-torque by impeller-speed (required-T b ×N b ) is not substantially the same as and is greater than the product of delivered motor-torque by rotor-speed (delivered-T m ×N m ); and
decreasing the most recent voltage-frequency index R by a given decrement if the product of required blower-torque by impeller-speed (required-T b ×N b ) is not substantially the same as and is less than the product of delivered motor-torque by rotor-speed (delivered-T m ×N m ).
The voltage-frequency index comprises a normalized ratio of voltage to frequency (V/f) that either is linear such as when an arbitrarily chosen index value of unity®=1) corresponds to 100 V per 50 hertz and then the ratio of 200 V per 100 hertz corresponds to R=2, or is non-linear as when an arbitrarily chosen index value of unity®=1) corresponds to 100 V per 50 hertz and then the ratio of 200 V per 90 hertz corresponds to R=2.
The device serving the controller information corresponding to flow command information F optionally comprises either a device receiving the flow command information F from an input device or extracting it from a database. The other device serving the controller information corresponding to one of rotor speed N m or impeller speed N b further preferably comprises providing either the motor or the blower with a speed transducer.
The invention having been disclosed in connection with the foregoing variations and examples, additional variations will now be apparent to persons skilled in the art. The invention is not intended to be limited to the variations specifically mentioned, and accordingly reference should be made to the appended claims rather than the foregoing discussion of preferred examples, to assess the scope of the invention in which exclusive rights are claimed. | An apparatus and method for controlling an induction motor having a variable frequency drive in a blower system so that the blower system provides a specific fluid flow. A start-up program causes the motor to ramp up to approximately a predetermined steady state speed. A required blower torque is calculated by operating on a table of blower constants, a selected flow rate and a motor speed which is read from a speed sensor in the motor/blower system. A developed motor torque is calculated by operating on a table of motor specific constants, a voltage-frequency index and the motor speed taken from the speed sensor. The calculated required blower torque is repeatedly compared with the calculated developed motor torque. The voltage-frequency index to the variable frequency drive is modified to force the developed motor torque to converge with the required blower torque in a steady state. | 5 |
FIELD OF THE INVENTION
This invention relates to improved antenna techniques, particularly for Orthogonal Frequency Division Multiplexed (OFDM) communication systems.
BACKGROUND OF THE INVENTION
Orthogonal frequency division multiplexing is a well-known technique for transmitting high bit rate digital data signals. Rather than modulate a single carrier with the high speed data, the data is divided into a number of lower data rate channels each of which is transmitted on a separate subcarrier. In this way the effect of multipath fading is mitigated. In an OFDM signal the separate subcarriers are spaced so that they overlap, as shown for subcarriers 12 in spectrum 10 of FIG. 1 a. The subcarrier frequencies are chosen that so that the subcarriers are mutually orthogonal, so that the separate signals modulated onto the subcarriers can be recovered at the receiver. One OFDM symbol is defined by a set of symbols, one modulated onto each subcarrier (and therefore corresponds to a plurality of data bits). The subcarriers are orthogonal if they are spaced apart in frequency by an interval of 1/T, where T is the OFDM symbol period.
An OFDM symbol can be obtained by performing an inverse Fourier transform, preferably an Inverse Fast Fourier Transform (IFFT), on a set of input symbols. The input symbols can be recovered by performing a Fourier transform, preferably a fast Fourier transform (FFT), on the OFDM symbol. The FFT effectively multiplies the OFDM symbol by each subcarrier and integrates over the symbol period T. It can be seen that for a given subcarrier only one subcarrier from the OFDM symbol is extracted by this procedure, as the overlap with the other subcarriers of the OFDM symbol will average to zero over the integration period T.
Often the subcarriers are modulated by QAM (Quadrature Amplitude Modulation) symbols, but other forms of modulation such as Phase Shift Keying (PSK) or Pulse Amplitude Modulation (PAM) can also be used. To reduce the effects of multipath OFDM symbols are normally extended by a guard period at the start of each symbol. Provided that the relatively delay of two multipath components is smaller than this guard time interval there is no inter-symbol interference (ISI), at least to a first approximation.
FIG. 1 b shows an exemplary OFDM transmitter 100 (here in a mobile terminal, MT) and an exemplary OFDM receiver 150 (here in an access point, AP). In the transmitter 100 a source 102 provides data to a baseband mapping unit 104 , which optionally provides forward error correction coding and interleaving, and which outputs modulated symbols such as QAM symbols. The modulated symbols are provided to a multiplexer 108 which combines them with pilot symbols from a pilot symbol generator 106 , which provides reference amplitudes and phases for frequency synchronisation and coherent detection in the receiver (in other arrangements differential detection may be employed). The combination of blocks 110 converts the serial data stream from multiplexer 108 to a plurality of parallel, reduced data rate streams, performs an IFFT on these data streams to provide an OFDM symbol, and then converts the multiple subcarriers of this OFDM symbol to a single serial data stream. This serial (digital) data stream is then converted to an analogue time-domain signal by digital-to-analogue converter 112 , up-converted by up-converter 114 , and after filtering and amplification (not shown) output from an antenna 116 . Antenna 116 may comprise an omnidirectional antenna, a sectorised antenna or an array antenna with beamforming.
The signal from antenna 116 of transmitter 100 is received by an antenna 152 of receiver 150 via a “channel” 118 . Typically the signal arrives at antenna 152 as a plurality of multipath components, with a plurality of different amplitudes and phases, which have propagated via a plurality of different channels or paths. These multipath components combine at the receiver and interfere with one another to provide an overall channel characteristic typically having a number of deep nulls, rather like a comb, which generally change with time (particularly where the transmitter or receiver is moving). Often there will be a number of transmitters in the same general location, for example an office, and this gives rise to co-channel interference, which can be more problematic than multipath.
The antenna 152 of receiver 150 is coupled to a down-converter 154 and to an analogue-to-digital converter 156 . Blocks 158 then perform a serial-to-parallel conversion, FFT, and parallel-to-serial re-conversion, providing an output to demultiplexer 160 , which separates the pilot symbol signal 162 from the data symbols. The data symbols are then demodulated and de-mapped by base-band de-mapping unit 164 to provide a detected data output 166 . Broadly speaking the receiver 150 is a mirror image of the transmitter 100 . The transmitter and receiver may be combined to form an OFDM transceiver.
OFDM techniques may be employed in a variety of applications and are used, for example, for military communication systems and high definition TV. Here, applications of the invention will be discussed with particular reference to the HIPERLAN (High Performance Radio Local Area Network) Type 2 standard (www.etsi.org/technicalactiv/hiperlan2.htm, and DTS/BRAN-0023003 v 0.k). Although applications of the invention are not limited to this environment HIPERLAN 2 wireless local area network communications are managed by a common node, the access point.
The receiver of FIG. 1 b is somewhat simplified as, in practice, there is a need to synchronise the FFT window to each OFDM symbol in turn, to avoid introducing non-orthogonality and hence ISI/ICI (Inter-Symbol Interference/Inter-Carrier Interference). This may be done by auto-correlating an OFDM symbol with the cyclic extension of the symbol in the guard period but it is generally preferable, particularly for packet data transmission, to use known OFDM (training) symbols which the receiver can accurately identify and locate, for example using a matched filter. It will be appreciated that this matched filter operates in the time domain, that is before the FFT is carried out (as opposed to the post-FFT frequency domain). In a packet data system data packets may be provided with a preamble including one or more of these training symbols.
FIGS. 2 a and 2 b show, respectively, a receiver front end 200 and receiver signal processing blocks 250 of a HIPERLAN 2 mobile terminal (MT) OFDM receiver. The receiver 250 shows some details of the analogue-to-digital conversion circuitry 252 , the synchronisation, channel estimation and control circuitry 252 and the de-packetising, de-interleaving and error correcting circuitry 256 .
The front end 200 comprises a receive antenna 202 coupled to an input amplifier 204 and a mixer 206 , which has a second input from an IF oscillator 208 to mix the RF signal to IF. The IF signal is then provided to an automatic Automatic Gain Control (AGC) amplifier 212 via a band pass filter 210 , the AGC stage being controlled by a line 226 from control circuitry 254 , to optimise later signal quantisation. The output of AGC 212 provides an input to two mixers 214 , 216 , which are also provided with quadrature signals from an oscillator 220 and splitter 218 to generate quadrature I and Q signals 222 , 224 . These I and Q signals are then over-sampled, filtered and decimated by analogue-to-digital circuitry 252 . The over-sampling of the signal aids the digital filtering, after which the signal is rate reduced to the desired sample rate.
It is desirable (but not absolutely essential) to compensate for the effects of the transmission channel. This can be done using a known symbol, for example in preamble data or one or more pilot signals. In the receiver 250 of FIG. 2 a known preamble symbol, referred to as the “C symbol”, is used to determine a channel estimate. The receiver synchronises to the received signal and switch 258 is operated to pass the received C symbol to channel estimator 260 . This estimates the effect of the channel (amplitude change and phase shift of the symbols in the sub-carriers) on the known C symbol so that the effects of the channel can be compensated for, by multiplying by the reciprocal (or complex conjugate) of the channel response Alternatively the one or more pilot signals (which also contain known symbols) can be used to determine a channel estimate. Again the phase rotation and amplitude change required to transform the received pilot into the expected symbol can be determined and applied to other received symbols. Where more than one pilot is available at more than one frequency improved channel compensation estimates can be obtained by interpolation/extrapolation to other frequencies using the different frequency pilot signals.
In FIG. 2 the receiver front end 200 will generally be implemented in hardware whilst the receiver processing section 250 will often be implemented in “software”, as illustrated schematically by Flash RAM 262 using, for example, ASICs, FPGAs or one or more DSP (digital signal processor) chips. A similar division between hardware and software will generally be present in the transmitter. However the skilled person will recognise that all the functions of the receiver of FIG. 2 (or of an equivalent transmitter) could be performed in hardware. Similarly the exact point at which the signal is digitised in a software radio will generally depend upon a cost/complexity/power consumption trade-off, as well as upon the availability of suitable high speed analogue/digital converters and processors, and that the RF signal could be digitised at IF or a higher frequency.
FIG. 3 shows an example of a Media Access Control (MAC) frame 300 of a packet data communications system including preamble sequences. The MAC frame includes a broadcast channel (BCH) burst 302 , a frame channel (FCH) burst 304 , an access feedback channel (ACH) burst 306 , a down-link (DL) burst 308 , an up-link (UL) burst 310 , a direct link (DiL) burst 312 , and a random access (RCH) burst 314 , all of which contain a preamble sequence.
FIGS. 4 a to e show, respectively, a broadcast burst, downlink burst, an uplink burst with a short preamble, uplink burst with a long preamble, and a direct link burst of a HIPERLAN 2 physical layer signal. Each of these bursts comprises a preamble portion 400 and a data payload portion 402 . The preamble portions 400 comprise one or more of three basic OFDM symbols, denoted A, B and C. The values of these symbols are known and A and B (and, if desired, C) can be recovered in the time domain (pre-FFT). These symbols are generally used to establish the frame and frequency synchronisation and to set the FFT window for the data following the symbols; they may also be employed to control AGC stage 212 . In the receiver of FIGS. 2A and B are recovered in the time domain and C is recovered in the frequency domain, that is post-FFT.
FIG. 5 illustrates, schematically, the use of these (known) preamble symbols for frame detection 502 based on RSSI (Received Signal Strength Indication), automatic gain control 504 , frame synchronisation 506 , and frequency synchronisation 508 ; a schematic illustration of the preamble portion of an MAC frame 500 is also illustrated for comparison.
FIG. 6 shows a plot 600 in the frequency and time domain illustrating the relative positions of preamble sequences 602 , pilot signals 604 , and data signals 606 for HIPERLAN 2, which has 48 data sub-carriers and 4 pilots (and one unused, central carrier channel 608 ). As can be seen from FIG. 6 the first four OFDM symbols comprise preamble data, and the pilot signals 604 continue to carry their preamble symbols. However on the remaining (data-bearing) sub-carriers OFDM symbols 5 onwards carry data. In other OFDM schemes similar plots can be drawn, although the preamble and pilot positions may vary (for example, the pilots need not necessarily comprise continuous signals).
It has previously been mentioned that OFDM is a useful technique for alleviating the effects of frequency selective fading caused by multipaths. However with particularly high data rates or in particularly severe multipath environments OFDM communications systems can still suffer from the effects of multipath fading. Moreover in indoor wireless environments, such as small office wireless LANs, there will often be a number of similar systems operating simultaneously in the same frequency band, because of limited spectrum availability. This can result in severe co-channel interference.
One technique which has been proposed for combatting such multipath and co-channel interference is the use of a sectorised transmit and/or receive antenna. The region to be covered is divided into a number of sectors, typically 3, 4 or 6, and one antenna (or more where diversity is employed) is provided for each sector, the patterns of the antennas being arranged to each cover mainly just one sector. In effect the main beam of each of the sector antennas points in a different direction and by selecting the transmit and/or receive direction the effects of multipath components and/or co-channel interference arriving from unwanted directions can be reduced. HIPERLAN 2, for example, supports the use of up to seven sectors at the Access Point. Some of the benefits of employing a sectorised switching array antenna in a HIPERLAN 2 environment are described in “Performance of HIPERLAN 2 using Sectorised Antennas” A. Dufexi, S. Armour, A. Nix, P. Karlsson and D. Bull, IEE Electronics Letters 15 Feb. 2001, volume 37 no. 4, page 245.
Another approach employed to mitigate the effects of multipath and co-channel interference uses a beamforming antenna array, such as a linear array of antenna elements in which the inter-antenna spacing is approximately one half a (carrier) wavelength. Signals from the antennas are combined, with appropriate phase and amplitude weightings, to provide a combined response with one or more lobes or beams. An array comprising n elements can be arranged to provide up to n−1 beams.
There are a number of different beamforming algorithms which may be applied to such an adaptive antenna array and details of these will be well known to the skilled person. One commonly used algorithm is the Constant Modulus Algorithm (CMA), described in J. R. Treichler and B. G. Agee, “A New Approach to Multipath Correction of Constant Modulus Signals”, IEEE Trans. Acoust. Speech and Signal Process., vol. ASSP-31, no. 2, page 459, 1983, which is hereby incorporated by reference. Broadly speaking this algorithm iteratively determines the weights for combining the signals from the antenna elements based upon a cost function chosen to make the spectrum of the combined signals approximately flat. The phase angles of the weights are chosen so that the beams point in the direction of maximum signal power, or, alternatively, so that nulls are formed in the directions of the unwanted multipath components or co-channel interference.
Determining appropriate weights for the antenna array elements is relatively straightforward in a narrow band system but in an OFDM receiver, where the bandwidth occupied by the group of sub-carriers is normally >1 MHz and in many cases >10 MHz, a single set of weights is unlikely to be optimal across the entire bandwidth and may only be valid, for example, at the centre of the frequency band. This can be understood, for example, from the consideration that the antenna element spacing, in terms of fractions of a sub-carrier wavelength, varies across the OFDM frequency band. In the receiver of FIG. 1 adaptive array weights may be applied at points 168 , 170 , or 172 but applying the array weights at positions 168 or 170 (pre-FFT) will not normally result in a good set of estimated weights across the frequency band.
One solution to this problem is therefore to apply weightings after the FFT, at point 172 , where different sets of weights can be applied to each sub-carrier. FIG. 7 shows an OFDM receiver 700 in which a separate set of weights is applied to each sub-carrier in this way. However it will be appreciated that with K sub-carriers and L antenna elements a total of K×L weights must be determined, which is a lengthy and processor-intensive task adding considerably to the receiver complexity. EP 0 852 407 describes an arrangement in which an operational band is partitioned into four equal sub-bands, one set of weights being calculated for each sub-band rather than for each sub-carrier, to reduce the number of weights to be calculated. However this is still a relatively complicated procedure and, moreover, produces a sub-optimal result. An alternative approach is described in Fujimoto et al, “A Novel Adaptive Array Utilising Frequency Characteristics”, IEICE Trans. Commun., vol. E 83-B, no. 2 February 2000, page 371, which is hereby incorporated by reference, in which the post-FFT separated sub-carriers are used to determine a single set of pre-FFT time domain weights using CMA. This approach provides a considerable simplification of the weight determining procedure but, again, the weights are sub-optimal.
The above-described sectorised antennas select a sector (or direction) which maximises received power. However in an environment where there is co-channel interference the received power from the interfering signal may be greater than that from the desired signal, in which case the antenna is controlled to point towards the interferer, worsening rather than improving the performance of the system. A particular difficulty arises in the context of OFDM symbols since these comprise a plurality of orthogonal carriers each of which is separately modulated with a datastream. As has been mentioned the conventional way to deal with such a signal is to transform it from the time (pre-FFT) into the frequency (post-FFT) domain where the signal processing is easier, but such a transformation imposes an undesirable overhead for a procedure such as selecting an element of a sectorised antenna, or beam-forming in an adaptive array. Therefore a need arises for simplified antenna techniques which are nevertheless capable of mitigating the effects of co-channel interference, in particular in difficult environments.
SUMMARY OF THE INVENTION
According to the present invention there is therefore provided a received signal selector for a received signal comprising a set of carriers, the received signal selector being configured for use with an antenna system comprising a plurality of antenna elements, the received signal selector comprising, a plurality of received signal inputs for receiving signals from the plurality of antenna elements, an interference detector for each of the received signal inputs, coupled to said received signal inputs to receive, from each input, a version of said received signal, and configured to provide an interference output for the set of carriers from each input, a selection controller configured to receive the interference output for each said input and having a control output, and a selector coupled to said received signal inputs and responsive to said control output to select one or more of said versions of said received signal for output.
The antenna system may comprise, for example, a sectorised antenna system or an array antenna. The received signal selector may be used in either a receiver, transmitter or transceiver and is preferably employed with OFDM signals. By effectively operating in the pre-FFT or time domain the complexity is significantly reduced as compared with prior art techniques, whilst still alleviating the influence of severe multipath and/or co-channel interference. This in turn facilitates a high data throughput and allows the capacity of a communications system in which the received signal selector is employed to be increased. Furthermore the relative simplicity of the structure enables the power consumption of baseband LSI (Large Scale Integration) components to be reduced as compared with prior art techniques, both in base stations and mobile terminals. Embodiments of the invention also facilitate real-time operation, even in very high clock speed systems.
The selector may select signals from one or more of the antenna elements based upon the detected level of interference on the signals from the elements, selecting signals from an element or elements with the least interference. Preferably, however, the antenna elements are selected based upon signal-to-interference (SIR), one or more elements with the greatest SIR being selected. Thus preferably a signal detector is also provided for each of the antenna elements, although the skilled person will appreciate that such an arrangement may be realised by sharing one detector between the antenna elements.
Preferably the signal and interference detectors operate in the time domain, that is before the received signal has been transformed from the time domain to a frequency domain. Preferably the subcarriers are substantially mutually orthogonal and preferably they comprise subcarriers of an OFDM signal.
The signal and interference detectors may provide separate signal and interference outputs or a combined signal and interference detector may provide a combined output comprising, for example, a signal-to-interference ratio. One signal and interference detector may be provided for each antenna element or, alternatively, a single signal and interference detector may be shared between the elements, for example on a time-multiplexed basis. The functions of the received signal selector may be implemented in hardware or in software or in a combination of the two.
Preferably the signal and interference detectors determine the strength of the wanted signal and unwanted interference using a correlation technique; they may share a correlator or have separate correlators. To determine a measure of the interference to a received signal from one of the antenna elements the signal may be correlated with a first reference signal. This first reference signal is chosen to be substantially orthogonal to a known portion of the transmitted signal, such as a preamble sequence. To determine received signal strength the received signal may be correlated with a second reference signal which substantially corresponds to a known portion of the transmitted signal, again such as a preamble sequence.
Where the cross-correlation period (that is the position of the correlation window) is substantially the same for the signal strength detection and interference detection processes the first and second reference signals will be substantially mutually orthogonal. However this will not be the case where the cross-correlation periods are different, for example where preamble B is used for interference detection and preamble C is used for signal strength detection. (In this example the first reference signal, for determining the interference level, is orthogonal to the known preamble B and the second reference signal, for determining the signal strength, comprises preamble C itself).
The correlation is performed in the time-domain—that is the correlation is between two OFDM symbols and hence an inverse Fourier transform is performed on the known (preamble or pseudo-noise) data prior to the correlation. Preferably, therefore, the received signal selector includes a signal generator to generate the first and second reference signals. In most cases the receiver will know the preamble sequences used by the transmitter and the first and second reference signals can be generated from this information. However where this is not the case the receiver can estimate a preamble or pilot portion of the signal (or use blind algorithms) and generate the reference signals from that. The frequency domain signals will generally be known and time domain preamble sequences can therefore be generated using an IFFT. However this need not be performed in real-time and instead, for example, the relevant time domain preamble sequences can be predetermined and stored, say, in a look-up table.
In one implementation the antenna elements are directional antenna elements, for example elements of a sectorised antenna, and one version of the received signal is obtained from each antenna element. Alternatively signals from the antenna elements may provide inputs to a beamformer, such as a Butler matrix-type beamformer, which in turn provides the versions of the received signal to the interference detector and to the selector. In this latter case each version of the received signal will, in general, comprise a combination of the signals from all the antenna elements. However there is generally still a version of the received signal for each antenna element, that is the number of versions of the received signal generally corresponds to the number of antenna elements. Where beamforming is employed omnidirectional rather than directional antenna elements may be used.
The different versions of the received signals provide a degree of spatial diversity since, whether directional antenna elements or beamforming is employed, in general they will have arrived from different directions. The selection controller may be configured to select only one version of the received signal for further processing, preferably that with the greatest signal-to-interference ratio (SIR). Alternatively the selection controller may select more than one version of the received signal, again preferably those versions with the greatest signal-to-interference ratio. In other embodiments selection may be based upon the interference (aiming to minimise this) rather than upon the SIR, particularly where the level of interference is low.
Where the selection controller selects more than one version of the received signal these different versions may be combined. A conventional diversity technique may be employed for this, for example MRC (maximal ratio combining) to maximise the signal to noise ratio, or LMS (least mean squares), RLS (recursive least squares) or SMI (sample matrix inversion) for minimum mean square error (MMSE).
In a related aspect the invention provides an OFDM receiver for use with an antenna system comprising a plurality of directional antenna elements, the OFDM receiver having a plurality of inputs for said plurality of antenna elements and including a Fourier transform OFDM demodulator, the OFDM receiver further comprising a pre-Fourier transform domain signal and interference detector for each said antenna element, an element selection controller to receive signal and interference measures for each said antenna element from said signal and interference detector; and an antenna element selector responsive to said element selection controller to select signals from said antenna elements for demodulation by said OFDM demodulator. Again the antenna system may comprise, for example, a sectorised antenna or an array antenna system.
The invention also provides a method of selecting one or more received signals from an antenna system comprising a plurality of antenna elements, each said received signal comprising a set of carriers, the method comprising, determining an interference measure for the set of carriers comprising each said received signal, and selecting one or more of said received signals from said antenna elements using said interference measures.
The antenna system may comprise, for example, a sectorised antenna system or an array antenna. Preferably the carriers are substantially mutually orthogonal. Preferably the method comprises determining a signal-to-interference ratio for the set of carriers received by each antenna element; and selecting one or more of said antenna elements using said signal-to-interference ratios.
In a further aspect the invention provides a data carrier carrying processor control code to implement the above-described received signal selectors, receiver and methods. This processor control code may comprise computer programmed code, for example to control a digital signal processor, or other code such as a plurality of register values to set up a general purpose integrated circuit to implement the selector or method. The data carrier may comprise a storage medium such as a hard or floppy disk, CD- or DVD-ROM, or a programmed memory such as a read-only memory, or an optical or electrical signal carrier. As the skilled person will appreciate the processor control code may be also be distributed between a plurality of coupled components, for example on a network. The skilled person will further recognise that the invention may be implemented by a combination of dedicated hardware and functions implemented in software.
These and other aspects of the invention will now be further described, by way of example only, with reference to the accompanying figures in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a and 1 b show, respectively, an OFDM symbol and an exemplary OFDM transmitter;
FIGS. 2 a and 2 b show, respectively, a receiver front end, and signal processing blocks of a HIPERLAN 2 OFDM receiver;
FIG. 3 shows an exemplary Media Access Control frame of a packet data communications system;
FIGS. 4 a to 4 e show, respectively, a broadcast burst, a downlink burst, an uplink burst with a short preamble, an uplink burst with a long preamble, and a direct link burst of a HIPERLAN 2 physical layer signal;
FIG. 5 shows, schematically, uses of the preamble portion of a HIPERLAN 2 broadcast burst in a mobile terminal OFDM receiver;
FIG. 6 shows a frequency-time plot of a HIPERLAN 2 OFDM signal including preamble and pilot signals;
FIG. 7 shows an OFDM receiver in which a separate set of weights is applied to each sub-carrier in the frequency domain;
FIG. 8 shows a schematic diagram of a received signal selector according to an embodiment of the present invention;
FIGS. 9 a and 9 b show, respectively, a schematic diagram of a signal and interference detector, and a schematic diagram of a signal generator for the signal and interference detector of FIG. 9 a;
FIG. 10 shows a schematic diagram of a received signal selector according to a second embodiment of the present invention; and
FIG. 11 shows a schematic diagram of a received signal selector according to a third embodiment of the present invention.
DETAILED DESCRIPTION
Referring to FIG. 8 , this shows a schematic diagram of a received signal selector 800 according to an embodiment of the present invention. A sectorised or array antenna 802 comprises a plurality of antenna elements 802 a, b, c each coupled to a respective input 803 a, b, c of a signal and interference strength detector 804 a, b, c. Other conventional components such as downconverters and filters may be present between the antenna elements and the signal and interference strength detectors but, for simplicity, these arc not shown. Each signal and interference strength detector has a first output 806 a, b, c comprising a straight through version of the input signal, optionally buffered or amplified. These first output signals are provided to a switch or selector 808 which selectively provides one (or in other embodiments, more than one) of these signals to an output 810 (or to a set of outputs 810 ) in response to a control signal 812 .
Each signal and interference strength detector also has a second pair of outputs 814 a, b, c (shown as a single output) comprising a signal strength output and an interference strength output. Each of these pairs of outputs is provided to an element selection controller 816 which outputs a control signal 812 for selector 808 . The element selection controller uses the information relating to the (desired) signal strength and interference strength from each antenna element to select one or more of the elements based upon a selection rule.
In the embodiment of FIG. 8 the element selection controller 816 controls selector 808 to select the received signal which has the largest power (or strength) ratio of desired signal to interference. In a variant, which is particularly suitable for low interference conditions, the signal with the least interference may be selected.
The output 810 is then processed in a conventional manner, as previously described. Thus, in outline, a synchronisation process 818 is applied to determine a Fourier transform window, a Fourier transform process 820 , preferably an FFT process, is then applied to demodulate a received OFDM symbol and a demodulator 822 then demodulates output data 824 from the Fourier transformed OFDM symbol. Again, for simplicity, other features of the OFDM receiver, such as analogue-to-digital Conversion, are not shown.
FIG. 9 a illustrates an exemplary signal and interference detector 804 for the received signal selector 800 of FIG. 8 . The input signal on line 803 is provided to first and second cross-correlators 900 , 902 , the outputs of which are provided to a signal strength detector 904 and to an interference strength detector 906 respectively to provide signal 908 and interference 910 strength outputs (together comprising a pair of outputs 814 ) to the element selection controller 816 . Cross-correlator 900 cross-correlates the input signal with a known reference signal comprising a time-domain OFDM signal generated, for example, from a packet data frame preamble sequence. Cross-correlator 902 cross-correlates the input signal with a signal which is at least partially orthogonal to the known reference signal, and thus extracts an interference component from the input signal, as will be explained in more detail below.
Where the reference signal is derived from a preamble data sequence the output of the signal and interference strength detector 804 will only be valid when the preamble sequence is present. In this case the cross-correlators 900 , 902 may be arranged to operate over a time window during which the preamble sequence is present determined, for example, by the synchronisation process 818 . The signal and interference detection operation may be carried out at the beginning of data reception and/or every successive packet, or frame-by-frame. Alternatively one or more pilot signals transmitting a known data sequence substantially continuously may be extracted from the received signal and used in the cross-correlation process.
FIG. 9 b shows an exemplary signal generator 920 for providing the reference and orthogonal reference signals 912 , 914 . The signal generator 920 comprises, in the illustrated example, a preamble sequence generator 922 , to generate a preamble sequence 924 and a signal 926 orthogonal to the preamble sequence. These two signals are then inverse fast Fourier transformed by IFFT 928 to provide reference signals 912 and 914 . In a HIPERLAN 2 system the preamble sequence p may be generated using the polynomial s(x)=x 7 +x 4 +1 with an initial all ones state, replacing all “1”s with −1 and all “0”s with the number 1.
Since the preamble sequence(s) and IFFT parameters are normally known the IFFT need not be performed in the receiver. For example, appropriate time-domain preamble sequences may be calculated in advance and stored in a look-up table in the receiver.
The operation of the signal and interference detector may be understood by considering a signal (R+I) where R is a known reference symbol and I is an interference contribution. The correlation of (R+I) with R is proportional to R 2 , that is the result is a measure of the desired signal strength, assuming that the cross-correlation between the reference signal and the interference is low. The cross-correlation between (R+I) and R*, where R* is a signal substantially orthogonal to R, is equal to the cross-correlation of R* with I as the cross-correlation of R* with R is by definition zero. The cross-correlation of R* with I is a measure of the interference strength. Thus the outputs from the signal and interference strength detector 804 can be used to calculate a form of signal-to-interference ratio, which can then be used by the element selection controller 816 to select one or more antenna elements receiving signals with the least interference to the desired signal.
The correlation of two orthogonal sequences may be referred to as a zero-value-correlation, in mathematical terms,
∑ i = 1 N a i * b i = 0 ; (Equation 1)
where, a i is the first correlation sequence and b i is the second correlation sequence (both of length N). When the second correlation sequence is correlated with noise or co-channel or multipath interference the result is non-zero. The sequence a i is inserted into the data frame, for example, in the preamble. One way to format a zero-value-correlated sequence is from a pair of highly correlated sequences. A highly correlated sequence has the property:
R
xx
(
n
)
=
{
1
,
n
=
0
0
,
n
=
±
1
,
±
2
,
±
3
,
±
4
,
…
(Equation 2)
By combining a pair of this kind, zero-value-correlation sequences can be defined. Total received signal energy can be found by calculating the received power, and one measure of the level of unwanted interference energy is indicated by the peak level of the zero-value-correlated signal.
FIG. 10 shows a first alternative embodiment of a received signal selector 1000 , in which similar features to those of the received signal selector 800 of FIG. 8 are indicated by like reference numerals.
In FIG. 10 the element selection controller 816 controls selector 1002 to select two or more received signals, preferably those with the greatest signal to interference ratio, but alternatively those with the least interference. The selected signals are then combined, in a combiner 1004 , using an appropriate diversity method, such as maximal ratio combining (MRC). Optionally the signals for combining may be weighted according to a signal quality measure such as signal strength, interference level or, preferably, signal-to-interference ratio. The combined output 1006 from combiner 1004 takes the place of output 810 in the selector 800 of FIG. 8 .
The combiner forms a weighted combination of the signals from two or more antenna elements, for example based upon their determined signal strength or signal-to-interference ratio. The applied weights comprise an amplitude and phase value for each combined signal and, for MRC, these are selected to coherently combine the signals from the antenna elements. In MRC a weight may be determined from the complex conjugate of the channel response for the relevant antenna element.
The skilled person will recognise that any conventional diversity combining method may be employed. Alternatively combiner 1004 may implement an adaptive beamforming algorithm such as SMI (sample matrix inversion), although this is more complicated. Estimates of the weights may be derived, for example, using the pilot signals.
In the embodiment of FIG. 10 the two or more received signals selected are received by two or more corresponding antenna elements but in an alternative arrangement, described next, these signals may instead be selected from outputs of a beamformer.
FIG. 11 shows a further alternative embodiment of a received signal selector 1100 , again in which similar features to those of the received signal selector 800 of FIG. 8 are indicated by like reference numerals. In the embodiment of FIG. 11 the directional antenna elements 802 a,b,c are replaced by less directional or omnidirectional elements and a beamformer 1102 is used to provide directionality. The effect is similar to that of a sectorised antenna but provides greater flexibility. The physical configuration of a sectorised antenna, and in particular the directions in which the elements point, is fixed at the time of installation. By contrast using a beamforming approach with two or more antenna elements allows the formation of flexible beam patterns with directional lobes.
The beamformer 1102 operates differently to an adaptive beamformer with only a single output in that the beamformer has a plurality of outputs, preferably one for each of the antenna elements to which it is connected—three outputs corresponding to the three antenna elements in the illustrated embodiment. Each output is formed from a combination of the input signals and is characterised by a directional response. Thus in the illustrated embodiment three different directional responses are provided for the antenna system. It will be recognised that not all the outputs from the beamformer need be used and that, more generally, the number of outputs from the beamformer may be more (or fewer) than the number of antenna elements.
Suitable beamforming methods, some of which have been mentioned above, include analogue beamforming methods such as a Butler matrix method, and equivalent digital beamforming methods such as Fourier transform methods. These and other methods are described in more detail in J. E. Hudson, “Adaptive Array Principles”, Peter Peregrinus Limited, 1981, which is hereby incorporated by reference.
A multiple-beam beamforming network is sometimes known as a beamforming matrix, and the Butler matrix a well-known and simple example. A Butler matrix comprises a matrix of cascaded hybrid junctions and phase shifters linking a plurality of input ports to a plurality of output ports. Each output port is coupled to all the input ports, each output comprising a combination of signals from the input ports to which a set of phase shifts, determining a beam direction, has been applied. In general, although the beams may overlap they are mutually orthogonal. Beamforming networks, such as Butler matrix type networks, are available as off-the-shelf components from a range of suppliers.
In mathematical terms a beamforming network forming M beams may be characterised by an M-row matrix T, the output signal vector y(t) being related to the input signal vector u(t) by y(t)=T.u(t). Each column of T comprises a weight vector w and, where the beamforming network has M inputs for example for M antenna elements, T is an M×M matrix given by T=[w 0 , w 1 , w 2 . . . w M−1 ]. If the weight vectors w are orthogonal then so are the beams.
In a multiple-beam beamforming network such as a Butler matrix the beam directions may be changed by changing the phase shifts, for example by means of variable phase shifters. In embodiments of the invention, in a similar way to that in which elements of a sectorised antenna may be selected, the beams may be selected (or directed) according to received signal quality, for example so as to maximise the signal-to-interference ratio or minimise the interference.
Embodiments of the invention have been described in relation to a receiver but the invention may also be employed in a transmitter or in a transceiver. In a transmitter or transceiver the selection of one or more antenna elements for transmitting signals may be based upon the same criteria as in reception. For example, if the received: signal-to-interference ratios indicate that a particular antenna element should be used for reception, this same element may also be used for transmission where the uplink (from mobile terminal to base station) and downlink channel (from base station to mobile terminal) properties are reciprocal. This is particularly the case where transmission and reception are at the same frequency, for example in a time division duplex (TDD) system. Transmitting in the direction(s) found to provide the optimum received signal will, because of reciprocity, tend to assist further in mitigating the effects of interference.
No doubt many effective alternatives will occur to the skilled person and the invention is not limited to the described embodiments but encompasses modifications within the spirit and scope of the attached claims. | A received signal selector for a received signal, the received signal including a set of carriers, the received signal selector being configured for use with an antenna system including a plurality of antenna elements. The received signal selector includes a plurality of received signal inputs for receiving signals from the plurality of antenna elements, an interference detector for each of the received signals inputs, coupled to the received signal inputs to receive, from each input, a version of the received signal, and configured to provide an interference output for the set of carriers from each input, a selection controller configured to receive the interference output for each input and having a control output, and a selector coupled to the received signal inputs and responsive to the control output to select one or more of the versions of the received signal for output. The invention provides a simplified technique for mitigating the effects of co-channel interference and severe multipath distortion. | 7 |
The invention relates to a protective layer on color proofs. More particularly, this invention relates to a protective polymeric layer for color proofs, a process for applying the protective layer on a color proof, and a color proof provided with a protective layer.
Screened color separations are used in reprography as copy originals for preparing offset or letterpress printing plates. Before the printing plates are exposed, the color separations are checked with the aid of color proofing processes for whether the subsequent printing result is a tonally accurate reproduction of the original.
Such color proofing processes use, for example, photosensitive recording materials with which the image is produced by using adhesion differences in the exposed and unexposed areas of the photosensitive layer. A positive-working reproduction process is disclosed in U.S. Pat. No. 3,649,268 in which a tacky photopolymerizable recording material is laminated on an image support and hardened by imagewise exposure. The exposed image areas lose their tackiness. The image can then be developed by applying colored particulate materials such as toners or pigments which selectively adhere to the unexposed tacky image areas. A negative-working process is described in U.S. Pat. No. 4,174,216 which teaches a negative-working element a support; a tacky, non-photosensitive contiguous layer; a photohardenable photoadherent layer; and a strippable cover sheet. After imagewise exposure to actinic radiation, the coversheet is peeled away, carrying with it the exposed areas of the photoadherent layer and revealing the tacky contiguous layer beneath. These tacky areas may then be toned with, for example, finely divided particulate material. Different colored layers can be prepared and assembled in register over one another to form multilayer color proofs, as is well know to those skilled in the art. U.S. Pat. No. 4,053,313 describes a similar negative-working system which is developed by solvent washout.
Other known photosensitive recording materials for preparing color proofs include precolored layers instead of tonable photosensitive layers, whereby the exposed material is developed by washoff with solvents as well as by peel-apart methods. The prior art also includes systems wherein the tackiness is increased by exposure to actinic radiation instead of being reduced as in the systems described above.
Color proofs are generally provided with an added protective layer to protect against mechanical and chemical interactions. For this purpose, a layer of a photopolymerizable material can be applied and polymerized overall, as described in U.S. Pat. No. 4,174,216. This process has the disadvantage that an additional exposure step is necessary. Further, there are various special protective layers of non-photosensitive materials. Double layer materials having an antiblocking layer and an adhesion layer are described in EP-B 0 242 655. Similarly, a combination of an actual protective layer of synthetic resin films and an adhesion layer is described in U.S. Pat. No. 4,329,420. Single layer materials are described in EP-B 0 285 039 and EP-B 0 365 355. According to EP-B 0 285 039, mixtures of special incompatible polymers are used. According to EP-B 0 365 355, thermoplastic resins having a Tg of 50 to 80° C. must be used.
The present invention is based on the problem of making available effective protection for color proofs against mechanical and chemical interactions, such protection having properties stable during storage of the color proofs at room temperature, without damaging the resolution or the tonal reproduction of the color proofs, or distorting the color images and without added processing steps or added auxiliary layers being required.
SUMMARY OF THE INVENTION
The present invention is directed to an element comprising a strippable support film and at least one protective layer including at least one polymer having a melting point Tin of at least about 50° C. and a glass transition temperature Tg of at most about 0° C. The element of the present invention is especially useful to provide a protective layer on proofs.
In another embodiment, the invention is directed to an article comprising an image disposed on at least one surface of a substrate, the image optionally comprising multiple color images, and a protective layer on the image-bearing surface of the substrate, characterized in that the protective layer includes at least one polymer having a melting point Tm of at least about 50° C. and a glass transition temperature Tg of at most about 0° C.
In still another embodiment, the invention is directed to a process for applying a protective layer on an image-bearing surface to form an article having an image disposed on at least one surface of a substrate, the image optionally comprising multiple color images, and a protective layer on the image-bearing surface of the substrate, characterized in that the protective layer includes at least one polymer having a melting point Tm of at least about 50° C. and a glass transition temperature Tg of at most about 0° C., the process comprising:
providing an element comprising a support film and a protective layer, the protective layer having a free surface and an opposing support surface adjacent the support film;
adhering the free surface of the protective layer to the image-bearing surface, the image-bearing surface optionally comprising multiple color images; and
removing the support film, whereby the protective layer is transferred onto the image bearing surface.
The invention itself, together with further objects and attendant advantages, will best be understood by reference to the following detailed description of the preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Protective Element:
The element for application to an image-bearing surface comprises a strippable support film and at least one protective layer including at least one polymer having a melting point Tm of at least about 50° C. and a glass transition temperature Tg of at most about 0° C. Mixtures of polymers having the above characteristics may also be used in the non-photosensitive protective layer. In a preferred embodiment, the protective layer is transparent and non-photosensitive.
The protective element of this invention may be applied to many types of image-bearing surfaces. Some examples of image-bearing surfaces include Cromalin® proofs, Easyprint® proofs, etc.
The protective layer can be prepared by known methods. For this purpose, they can be coated on suitable supports from currently available solvents, preferably organic solvents, such as, for example, methylene chloride, toluene/methanol mixtures, or other mixtures of aromatic solvents and alcohols, esters, or ketones, and subsequently dried.
The thickness of the protective layer is usually about 1-20 μm, preferably about 3-15 μm, and particularly preferred at about 5-10 μm. A composite of two or more layers is also possible for this protective element. Two or more layers having the above specified thermoplastic polymers can be applied on the support successively or simultaneously by known methods. The layers of such multilayer protective elements can have the same or different compositions. Single-layer elements are preferred.
Polymer:
Useful polymers have a melting point Tm of at least about 50° C. and a glass transition temperature of at most about 0° C. Preferred polymers have a melting point Tm of about 50-120° C., particularly about 50-100° C., and a glass transition temperature Tg of at most about −20° C., particularly at most about −40° C. Suitable polymers include, for example, polyethylene oxides, polypropylene oxides, polytetrahydrofurans, polycaprolactones and combinations thereof. Polycaprolactones, polyethylene oxides and polypropylene oxides are particularly preferred, especially polycaprolactones. The polymer is present in the amount of from about 80 to about 100% by weight, preferably from about 90 to about 100% by weight, based on the total weight of the layer.
Additives:
The protective layer can also contain additives, such as, for example, UV absorbers, optical brighteners, fillers, surfactants, and antistatic agents. In particular, addition of fillers, such as, for example, silicates, aluminum oxides, and silicon dioxides, etc., are advantageous. Pyrogenic and precipitated silicic acids are preferred. Fillers are present in the amount of from 0 to about 15% by weight, preferably from 0 to about 10% by weight, based on the total weight of the layer.
Supports:
Suitable supports are, for example, synthetic resin films of polyethylene, polypropylene, polyamides, or polyesters. Polyethylene terephthalate films are particularly preferred. Supports having smooth or rough surfaces can be used. Support films having release layers or ED-treated support films are also suitable. The thickness of the support is usually at least about 12 μm, preferably about 20-130 μm, particularly preferred at about 20-75 μm.
Image Bearing Surfaces:
The protective layer is suitable for use on all current proofs. Examples are positive-working recording materials described in U.S. Pat. No. 3,649,268, negative-working materials described in U.S. Pat. No. 4,174,216 and U.S. Pat. No. 4,053,313, and materials having precolored recording layers as described in U.S. Pat. No. 4,260,673. The colored image may optionally include multiple color images.
The protective layer can also be useful on other image bearing surfaces such as, for example, photographic images, disublimation images, and laser ablation/inkjet images.
Process:
The protective layer can be applied with current commercial laminators onto a commercial color proofing material having an image-bearing surface. This image bearing surface may optionally contain multiple color images. Rolls as well as sheet stock can be used. The temperature of the laminator rollers is usually about 60-150° C., preferably about 70-130° C., particularly preferred at about 90-120° C. The support film is stripped off manually or automatically, transferring the protective layer completely onto the image bearing surface of the color proof. The support film is stripped off preferably after the color proof has cooled to room temperature.
The following examples illustrate the invention. Parts and percentages are by weight, unless otherwise stated. The average molecular weights of the polymers are given as weight average {Mw}.
EXAMPLE 1
8.28 g Capa® 240 manufactured by Solvay Interox, Warrington, Great Britain (Mw 4000, melting range Tm 55-60° C., glass transition temperature range Tg −60 to −70° C.) and 8.28 g Capa® 650 manufactured by Solvay Interox, Warrington, Great Britain (Mw 50,000, melting range Tm 58-60° C., glass transition temperature range Tg −60 to −70° C.) were dissolved at room temperature in a solvent mixture of 71.4 g toluene and 30.6 g methanol. Then, 1.44 g Acematt® OK 607 manufactured by Degussa, Frankfurt, Germany were dispersed in this solution with a blade agitator. This coating dispersion was applied on a smooth polyester film that had not been surface-treated (Mylar® 92A from E. I. du Pont de Nemours and Company, Wilmington, Del.) and dried. The dry layer thickness was 5 μm. This element was laminated on a four-color Cromalin® proof in a commercial Cromalin® Whiteline laminator from the DuPont Company at 120° C. roller temperature. After cooling to room temperature, the polyester film was stripped off. A color proof was obtained with a glossy, hard, and nontacky surface. When the color proof was flexed, the protective layer remained elastic and did not flake off.
EXAMPLE 2
A coating solution was made, as in Example 1, of 16.66 g Capa® 650 in 71.4 g toluene and 30.6 g methanol and applied on a smooth polyester film (Mylar® 92A) having a silicone layer. After drying, the coating thickness was 10 μm. This element was laminated on an Easyprint® four-color proof in an Easyprint® laminator from the DuPont Company at 110° C. roller temperature. After cooling to room temperature, the polyester film was stripped off. A color print having a glossy, hard, and nontacky surface was obtained. When the color proof was flexed, the protective layer remained elastic and did not flake off.
EXAMPLE 3
A coating dispersion was made, as in Example 1, of 16.56 g Capa® 650, 1.44 g Acematt® OK 607, 71.4 g toluene and 30.6 g methanol and applied on a smooth polyester film (Mylar® 92A) having a silicone layer. After drying, the coating thickness was 10 μm. This element was laminated on an Easyprint® four-color proof in an Easyprint® laminator from the DuPont Company at 110° C. roller temperature. After cooling to room temperature, the polyester film was stripped off. A color print having a glossy, hard, and nontacky surface was obtained. When the color proof was flexed, the protective layer remained elastic and did not flake off.
EXAMPLE 4
A coating dispersion was made, as in Example 1, of 9.9 g Capa® 240, 6.66 g Capa® 650, 1.44 g Acematt® OK 607, 71.4 g toluene and 30.6 g methanol and applied on a rough polyester film that had not been surface-treated (Mylar® 92 EB 11 from the DuPont Company). After drying, the coating thickness was 10 μm. This element was laminated on an Easyprint® four-color proof in an Easyprint® laminator from the DuPont Company at 110° C. roller temperature. After cooling to room temperature, the polyester film was stripped off. A color print having a matte, hard, and nontacky surface was obtained. When the color proof was flexed, the protective layer remained elastic and did not flake off.
EXAMPLE 5
2.88 g polyethylene glycol PEG 8000 manufactured by Union Carbide, Tarrytown, N.Y. and 5.4 g polyethylene oxide WSRN 10 manufactured by Union Carbide, Tarrytown, N.Y. were dissolved at room temperature in a solvent mixture of 45.90 g toluene and 5.10 g methanol. This coating solution was applied on a smooth polyester film that had not been surface-treated (Mylar® 92A) and dried. The dry layer thickness was 5 μm. This element was laminated on a four-color Cromalin® proof as described in Example 1. After cooling to room temperature, the polyester film was stripped off. A color proof was obtained with a glossy, hard, and nontacky surface. When the color proof was flexed, the protective layer remained elastic and did not flake off.
EXAMPLE 6
Several of each of the color proofs prepared in Examples 1-5 were stored for 24 hrs. at 40° C. in a hot box. The color proofs were stored partially front to front and partially front to back. This stack was loaded with a weight of 500 g/dm 2 . No changes occurred in the color proof surfaces and the color proofs were separated without difficulty.
Of course, it should be understood that a wide range of changes and modifications can be made to the preferred embodiment described above. It therefore is intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it be understood that it is the following claims, including all equivalents, which are intended to define the scope of this invention. | Element for laminating on color proofs, comprising a strippable support film A and a transparent, photoinsensitive protective layer B, containing at least one polymer having a melting point Tm of ≧50° C. and a glass transition temperature Tg of ≦0° C. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a division of U.S. Ser. No. 09/886,592, filed Jun. 21, 2001, entitled “Adaptive Control For A Refrigeration System Using Pulse Width Modulated Duty Cycle Scroll Compressor;” which is a division of U.S. Ser. No. 09/524,364, filed Mar. 14, 2000 U.S. Pat. No. 6,408,635; which is a division of U.S. Ser. No. 08/939,779, filed Sep. 29, 1997, now U.S. Pat. No. 6,047,557; which is a continuation-in-part of U.S. Ser. No. 08/486,118, filed Jun. 7, 1995, now U.S. Pat. No. 5,741,120, each of which is incorporated herein by reference.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to refrigeration systems, compressor control systems and refrigerant regulating valve control systems. More particularly, the invention relates to a refrigeration system employing a pulse width modulated compressor or evaporator stepper regulator controlled by a variable duty cycle signal derived from a load sensor. Preferably an adaptive controller generates the variable duty cycle signal. The compressor has two mechanical elements separated by a seal, and these mechanical elements are cyclically movable relative to one another to develop fluid pressure. The compressor includes a mechanism to selectively break the seal in response to the control signal, thereby modulating the capacity of the system.
The refrigeration system can be deployed as a distributed system in refrigeration cases and the like. The preferred arrangement allows the compressor and condenser subsystems to be disposed in or mounted on the refrigeration case, thereby greatly reducing the length of refrigerant conduit and refrigerant required.
Conventionally, refrigeration systems for supermarket refrigeration cases have employed air-cooled or water-cooled condensers fed by a rack of compressors. The compressors are coupled in parallel so that they may be switched on and off in stages to adjust the system cooling capacity to the demands of the load. Commonly, the condensers are located outside, on the roof, or in a machine room adjacent the shopping area where the refrigeration cases are located.
Within each refrigeration case is an evaporator fed by lines from the condensers through which the expanded refrigerant circulates to cool the case. Conventionally, a closed-loop control system regulates refrigerant flow through the evaporator to maintain the desired case temperature. Proportional-integral-derivative (PID) closed loop control systems are popular for this purpose, with temperature sensors and/or pressure sensors providing the sensed condition inputs.
It is common practice within supermarkets to use separate systems to supply different individual cooling temperature ranges: low temperature (for frozen foods, ice cream, nominally −25 F.); medium (for meat, dairy products, nominally +20 F.); high (for floral, produce, nominally +35 to +40 F.). The separate low, medium and high temperature systems are each optimized to their respective temperature ranges. Normally, each will employ its own rack of compressors and its own set of refrigerant conduits to and from the compressors and condensers.
The conventional arrangement, described above, is very costly to construct and maintain. Much of the cost is associated with the long refrigerant conduit runs. Not only are long conduit runs expensive in terms of hardware and installation costs, but the quantity of refrigerant required to fill the conduits is also a significant factor. The longer the conduit run, the more refrigerant required. Adding to the cost are environmental factors. Eventually fittings leak, allowing the refrigerant to escape to atmosphere. Invariably, long conduit runs involve more pipefitting joints that may potentially leak. When a leak does occur, the longer the conduit run, the more refrigerant lost.
There is considerable interest today in environmentally friendly refrigeration systems. Shortening the conduit run is seen as one way to achieve a more environmentally friendly system. To achieve this, new condenser/compressor configurations and new control systems will need to be engineered.
Re-engineering condenser/compressor configurations for more environmentally friendly systems is not a simple task, because system efficiency should not be sacrificed. Generally, the conventional roof-mounted condenser system, supplied by condensers, benefits from economies of scale and is quite efficient. These systems serve as the benchmark against which more environmentally friendly systems of the future will need to be measured.
To appreciate why re-engineering an environmentally yet efficient system has proven so difficult, consider these thermodynamic issues. The typical refrigeration case operates in a very unpredictable environment. From a design standpoint, the thermal mass being cooled is rarely constant. Within the supermarket environment, the temperature and humidity may vary widely at different times of day and over different seasons throughout the year. The product load (items in the refrigeration case) can also change unpredictably. Customers removing product and store clerks replenishing product rarely synchronize. Outside the supermarket environment, the outdoor air temperature and humidity may also vary quite widely between day and night and/or between summer and winter. The capacity of the system must be designed for the harshest conditions. (when the condenser environment is the hottest). Thus systems may experience excess capacity in less harsh conditions, such as in the cool evenings or during the winter.
Periodic defrosting also introduces thermal fluctuations into the system. Unlike thermal fluctuations due to environmental conditions, the thermal fluctuations induced by the defrost cycle are cause by the control system itself and not by the surrounding environment.
In a similar fashion, the control system for handling multiple refrigeration cases can induce thermal fluctuations that are quite difficult to predict. If all cases within a multi-case system are suddenly turned on at once—to meet their respective cooling demands—the cooling capacity must rapidly be ramped up to maximum. Likewise, if all cases are suddenly switched off, the cooling capacity should be ramped down accordingly. However, given that individual refrigeration cases may operate independently of one another, the instantaneous demand for cooling capacity will tend to vary widely and unpredictably.
These are all problems that have made the engineering of environmentally friendly systems more difficult. Adding to these difficulties are user engineering/ergonomic problems. The present day PID controller can be difficult to adapt to distributed refrigeration systems. Experienced controls engineers know that a well-tuned PID controller can involve a degree of artistry in selecting the proper control constants used in the PID algorithm. In a large refrigeration system of the conventional architecture (non-distributed) the size of the system justifies having a controls engineer visit the site (perhaps repeatedly) to fine tune the control constant parameters.
This may not be practical for distributed systems in which the components are individually of a much smaller scale and far more numerous. By way of comparison, a conventional system might employ one controller for an entire multi-case, store-wide system. A distributed system for the same store might involve a controller for each case or adjacent group of cases within the store. Distributed systems need to be designed to minimize end user involvement. It would therefore be desirable if the controller were able to auto configure. Currently control systems lack this capability.
The present invention provides a distributed refrigeration system in which the condenser is disposed on the refrigeration case and serviced by a special pulse width modulated compressor that may be also disposed within the case. If desired, the condenser and compressor can be coupled to service a group of adjacent refrigeration cases, each case having its own evaporator. The pulse width modulated compressor employs two mechanical elements, such as scroll members, that move rotationally relative to one another to develop fluid pressure for pumping the refrigerant. The compressor includes a mechanism that will selectively break the seal between the two mechanical elements, thereby altering the fluid pressure developed by the compressor while allowing the mechanical elements to maintain substantially constant relative movement with one another. The compressor can be pulse width modulated by making and breaking the fluid seal without the need to start and stop the electric motor driving the mechanical elements.
The pulse width modulated compressor is driven by a control system that supplies a variable duty cycle control signal based on measured system load. The controller may also regulate the frequency (or cycle time) of the control signal to minimize pressure fluctuations in the refrigerant system. The on time is thus equal to the duty cycle multiplied by the cycle time, where the cycle time is the inverse of the frequency.
The refrigeration system of the invention has a number of advantages. Because the instantaneous capacity of the system is easily regulated by variable duty cycle control, an oversized compressor can be used to achieve faster temperature pull down at startup and after defrost, without causing short cycling as conventional compressor systems would. Another benefit of variable duty cycle control is that the system can respond quickly to sudden changes in condenser temperature or case temperature set point. The controller adjusts capacity in response to disturbances without producing unstable oscillations and without significant overshoot. Also, the ability to match instantaneous capacity to the demand allows the system to operate at higher evaporator temperatures. (Deep drops in temperature experienced by conventional systems at overcapacity are avoided.)
Operating at higher evaporator temperatures reduces the defrost energy required because the system develops frost more slowly at higher temperatures. Also, the time between defrosts can be lengthened by a percentage proportional to the accumulated runtime as dictated by the actual variable duty cycle control signal. For example, a sixty percent duty cycle would increase a standard three-hour time between defrosts to five hours (3/0.60=5).
The pulse width modulated operation of the system yields improved oil return. The refrigerant flow pulsates between high capacity and low capacity (e.g. 100% and 0%), creating more turbulence which breaks down the oil boundary layer in the heat exchangers.
Another benefit of the variable duty cycle control system is its ability to operate with a variety of expansion devices, including the simple orifice, the thermal expansion valve (TXV) and the electronic expansion valve. A signal derived from the expansion device controller can be fed to the compressor controller of the invention. This signal allows the variable duty cycle control signal and/or its frequency to be adjusted to match the instantaneous operating conditions of the expansion device. A similar approach may be used to operate variable speed fans in air cooled condenser systems. In such case the controller of the invention may provide a signal to control fan speed based on the current operating duty cycle of the compressor.
Yet another benefit of the invention is its ability to detect when the system is low on refrigerant charge, an important environmental concern. Low refrigerant charge can indicate the presence of leaks in the system. Low charge may be detected by observing the change in error between actual temperature and set point temperature as the system duty cycle is modulated. The control system may be configured to detect when the modulation in duty cycle does not have the desired effect on temperature maintenance. This can be due to a loss of refrigerant charge, a stuck thermal expansion valve or other malfunctions.
For a more complete understanding of the invention, its objects and advantages, refer to the following specification and to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a system block diagram of a prior art refrigeration system-configuration;
FIG. 2 is a block diagram of a refrigeration system in accordance with the present invention;
FIG. 3 is a cross-sectional view of an embodiment of the pulse width modulated compressor, shown in the loaded state;
FIG. 4 is a cross-sectional view of the compressor of FIG. 3, shown in the unloaded state;
FIG. 5 is another embodiment of a refrigeration or cooling system in accordance with the present invention;
FIG. 6 is a block diagram of the controller;
FIG. 7 is a block diagram showing how the controller may be used to modulate an evaporator stepper regulator;
FIG. 8 is a block diagram of the signal conditioning module of the controller of FIG. 6;
FIG. 9 is a block diagram of the control module of the controller of FIG. 6;
FIG. 10 is a state diagram depicting the operating states of the controller;
FIG. 11 is a flowchart diagram illustrating the presently preferred PI control algorithm;
FIG. 12 is a waveform diagram illustrating the variable duty cycle signal produced by the controller and illustrating the operation at a constant frequency;
FIG. 13 is a waveform diagram of the variable duty cycle signal, illustrating variable frequency operation;
FIG. 14 is a series of graphs comparing temperature and pressure dynamics of system employing the invention with a system of conventional design;
FIG. 15 is a block diagram illustrating the adaptive tuning module of the invention;
FIG. 16 a is a flowchart diagram illustrating the presently preferred operation of the adaptive tuning module, specifically with respect to the decision whether to start tuning;
FIG. 16 b is a flowchart diagram illustrating the presently preferred process performed by the adaptive tuning module in the integration mode;
FIG. 16 c is a flowchart diagram illustrating the operation of the adaptive tuning module in the calculation mode;
FIG. 17 is a state diagram illustrating the operative states of the adaptive tuning module;
FIG. 18 is a block diagram illustrating the fuzzy logic block of the adaptive tuning loop;
FIG. 19 is a membership function diagram for the fuzzy logic block of FIG. 18;
FIG. 20 is a truth table relating to the membership function of FIG. 19 as used by the fuzzy logic block of FIG. 18;
FIG. 21 is an output membership function diagram for the fuzzy logic block of FIG. 18; and
FIG. 22 is a schematic illustrating exemplary sensor locations for control-related and diagnostic-related functions of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates how a conventional supermarket refrigeration system is configured. As previously discussed, it is conventional practice to place the compressors 30 and the condenser 32 in a location remote from the refrigeration cases 34 . In this illustration, the compressors 30 are configured in a parallel bank located on the roof 36 of the building. The bank of compressors supply a large condenser 32 , which may be air cooled or water cooled. The condenser supplies liquid refrigerant to a receiver 38 . The receiver 38 , in turn, supplies the individual refrigeration cases, which are connected in parallel, as illustrated. In most implementations a liquid line solenoid valve 40 is used to regulate flow to the associated evaporator 42 . The refrigerant is supplied to the evaporator through a suitable expansion device such as expansion valve 44 . The expansion valve 44 provides a restricted orifice that causes the liquid refrigerant to atomize into liquid droplets that are introduced into the inlet side of the evaporator 42 . The evaporator 42 , located within the refrigeration case 34 , extracts heat from the case and its contents by vaporization of the liquid refrigerant droplets into a gas. The compressors 30 extract this gas by suction and compress it back into the liquid state. The liquid refrigerant is then cooled in the condenser 32 and returned to the receiver 38 , whereupon the cycle continues.
To match cooling capacity to the load, the compressors 30 may be switched on and off individually or in groups, as required. In a typical supermarket arrangement there may be several independent systems, each configured as shown in FIG. 1, to handle different operating temperature ranges. Note that the liquid line 46 and the suction line 48 may each need to be quite lengthy (e.g., up to 150 feet) to span the distance from refrigeration case to roof.
FIG. 2 shows a refrigeration case 34 configured according to the principles of the present invention. The condenser 32 and compressor 30 are both disposed within case 34 or attached thereto. Evaporator 42 and the associated expansion valve 44 are likewise disposed within case 34 . The condenser 32 is provided with a heat removal mechanism 50 by which heat is transferred to ambient. The heat removal mechanism can be a water jacket connected to suitable plumbing for carrying waste heat to a water cooling tower located on the building roof. Alternatively, the heat removal mechanism can be a forced-air cooling system or a passive convection-air cooling system.
The refrigeration system of the invention employs a compressor controller 52 that supplies a pulse width modulated control signal on line 54 to a solenoid valve 56 on compressor 30 . The compressor controller adjusts the pulse width of the control signal using an algorithm described below. A suitable load sensor such as temperature sensor 58 supplies the input signal used by the controller to determine pulse width.
FIGS. 3 and 4 show the details of compressor 30 . FIG. 3 shows the compressor in its loaded state and FIG. 4 shows the compressor in its unloaded state. The solenoid valve 56 switches the compressor between these two states while the compressor motor remains energized. One important advantage of this configuration is that the compressor can be pulse width modulated very rapidly between the loaded and unloaded states without interrupting power to the compressor motor. This pulse width modulated cycling exerts less wear on the compressor, because the motor is not subjected to sudden changes in angular momentum.
Referring to FIGS. 3 and 4, there is shown an exemplary compressor 30 . Compressor 30 may be used within a hermetic scroll compressor such as generally of the type described in assignee's U.S. Pat. No. 5,102,316.
The exemplary compressor 30 includes an outer shell 61 and an orbiting scroll member 64 supported on upper bearing housing 63 and drivingly connect to crankshaft 62 via crank pin 65 and drive bushing 60 . A second non-orbiting scroll member 67 is positioned in meshing engagement with scroll member 64 and axially movably secured to upper bearing housing 63 . A partition plate 69 is provided adjacent the upper end of shell 61 and serves to define a discharge chamber 70 at the upper end thereof.
In operation, as orbiting scroll member 64 orbits with respect to scroll member 67 , suction gas is drawn into shell 61 via suction inlet 71 and thence into compressor 30 through inlet 72 provided in non-orbiting scroll member 67 . The intermeshing wraps provided on scroll members 64 and 67 define moving fluid pockets which progressively decrease in size and move radially inwardly as a result of the orbiting motion of scroll member 64 thus compressing the suction gas entering via inlet 72 . The compressed gas is then discharged into discharge chamber 70 via discharge port 73 provided in scroll member 67 and passage 74 .
In order to unload compressor 30 , solenoid valve 56 will be actuated in response to a signal from control module 87 to interrupt fluid communication to increase the pressure within chamber 77 to that of the discharge gas. The biasing force resulting from this discharge pressure will overcome the sealing biasing force thereby causing scroll member 67 to move axially upwardly away from orbiting scroll member 64 . This axial movement will result in the creation of a leakage path between the respective wrap tips and end plates of scroll members 64 and 67 thereby substantially eliminating continued compression of the suction gas.
A flexible fluid line 91 extends from the outer end of passage 90 to a fitting 92 extending through shell 61 with a second line 93 connecting fitting 92 to solenoid valve 56 . Solenoid valve 56 has fluid lines 82 and 84 connected to suction line 83 and discharge line 85 and is controlled by control module 87 in response to conditions sensed by sensor 88 to effect movement of non-orbiting scroll member 67 between the positions shown in FIGS. 3 and 4.
When compression of the suction gas is to be resumed, solenoid valve 56 will be actuated so as to move scroll member 67 into sealing engagement with scroll member 64 .
The refrigeration case embodiment of FIG. 2 may be packaged as a self-contained unit. While that may be a desirable configuration for many applications, the invention is not restricted to stand alone, self-contained refrigeration case configurations. Rather, the invention lends itself to a variety of different distributed refrigeration systems. FIG. 5 shows an example of such a distributed system.
Referring to FIG. 5, a single compressor 30 and condenser 32 can service several distributed refrigeration cases or several distributed cooling units in a heating and cooling (HVAC) system. In FIG. 5 the refrigeration cases or cooling system housings are shown as dashed boxes, designated 34 a, 34 b, and 34 c. Conveniently, the compressor 30 and condenser 32 may be disposed within or attached to one of the refrigeration cases or housings, such as refrigeration case or housing 34 a.
Each refrigeration case or housing has its own evaporator and associated expansion valve as illustrated at 42 ( a, b, c ) and 44 ( a, b, c ). In addition, each refrigeration case or housing may have its own temperature sensor 58 ( a, b, c ) supplying input information to the compressor controller 52 . Finally, a pressure sensor 60 monitors the pressure of the suction line 48 and supplies this information to compressor controller 52 . The compressor controller supplies a variable duty cycle signal to the solenoid valve 56 as previously described.
The multiple case or multiple cooling unit embodiment of FIG. 5 shows how a single compressor can be pulse width modulated by compressor controller 52 to supply the instantaneous demand for cooling. The temperature sensors 58 ( a, b, c ) collectively provide an indication of the load on the system, as does pressure sensor 60 . The controller adjusts the pulse width of the control signal to modulate the compressor between its high capacity and low capacity states (100%, 0%) to meet the instantaneous demand for refrigerant.
As an alternate control technique, one or more of the suction lines exiting the evaporator can be equipped with an electrically controlled valve, such as an evaporator pressure regulator valve 45 c. Valve 45 c is coupled to controller 52 , as illustrated. It may be supplied with a suitable control signal, depending on the type of the valve. A stepper motor valve may be used for this purpose, in which case controller 30 would supply a suitable signal to increment or decrement the setting of the stepper motor to thereby adjust the orifice size of the valve. Alternatively, a pulse width modulated valve could be used, in which case it may be controlled with the same variable duty cycle signal as supplied to the compressor 30 .
Controller 52 is not limited to solely compressor control applications. The variable duty cycle control signal can also be used to control other types of refrigerant flow and pressure control devices, such as refrigerant regulating valves. FIG. 7 shows such an application, where the output of controller 52 supplies control signals to evaporator stepper regulator 43 . This device is a fluid pressure regulator that is adjusted by stepper motor 45 . The evaporator stepper regulator (ESR) valve 43 adjusts the suction pressure to thereby adjust the capacity of the system.
A block diagram of the presently preferred compressor controller is illustrated in FIG. 6. A description of the various signals and data values shown in this and successive figures is summarized in Table I below.
TABLE I
Default
No.
Variable Name
Value
Description
1
Signal Conditioning:
Sensor Alarm
False
Indicates Sensor Reading is not
within expected range
Sensor Mode
Min
User configuration to indicate if
Min/Max/Avg is performed for
all temperature Sensors
Sampling Time (Ts)
0.5 sec
Rate at which Signal condition-
ing block is executed
Control Type
T/P Type
if controlled by only Temp. or
both Temp. & Pressure
2
Control Block:
Sensor Alarm
False
Same as before
System Alarm
False
Generated by Adaptive Block
indicative some system problem
SSL
0
Steady state loading %
Defrost Status
False
Whether system is in defrost
Pull_Down_Time
0
Time taken to pull down after
defrost
Gain (K)
7
Gain used in PI algorithm
Integral Time (Ti)
100
used in PI
Control Time (Tc)
10 Sec
used in PI
Control Set Pt. (St)
0 F.
used in PI
Operating State
1
What state the machine is
operating at
3
Defrost Control
Defrost Status
False
If defrost status of the case
Defrost Type
External
If the defrost is from external
timer or Internal clock of
controller
Defrost Interval
8 hrs
Time between defrost
Defrost Duration
1 hr
Defrost Duration
Defrost Termination
50 F.
Termination temperature for
Temp.
defrost
At the heart of the controller is control block module 102 . This module is responsible for supplying the variable duty cycle control signal on lead 104 . Module 102 also supplies the compressor ON/OFF signal on lead 106 and an operating state command signal on lead 108 . The compressor ON/OFF signal drives the contactors that supply operating current to the compressor motor. The operating state signal indicates what state the state machine (FIG. 10) is in currently.
The control block module receives inputs from several sources, including temperature and pressure readings from the temperature and pressure sensors previously described. These temperature readings are passed through signal conditioning module 110 , the details of which are shown in the pseudocode Appendix. The control block module also receives a defrost status signal from defrost control module 112 . Defrost control module 112 contains logic to determine when defrost is performed. The present embodiment allows defrost to be controlled either by an external logic signal (supplied through lead 114 ) or by an internal logic signal generated by the defrost control module itself. The choice of whether to use external or internal defrost control logic is user selectable through user input. 116 . The internal defrost control uses user-supplied parameters supplied through user input 118 .
The preferred compressor controller in one form is autoconfigurable. The controller includes an optional adaptive tuning module 120 that automatically adjusts the control algorithm parameters (the proportional constant K) based on operating conditions of the system. The adaptive tuning module senses the percent loading (on lead 104 ) and the operating state (on lead 108 ) as well as the measured temperature after signal conditioning (on lead 122 ). Module 120 supplies the adaptive tuning parameters to control block 102 , as illustrated. The current embodiment supplies proportional constant K on lead 124 and SSL parameter on lead 126 , indicative of steady-state loading percent. A system alarm signal on lead 126 alerts the control block module when the system is not responding as expected to changes in the adaptively tuned parameters. The alarm thus signals when there may be a system malfunction or loss of refrigerant charge. The alarm can trigger more sophisticated diagnostic routines, if desired. The compressor controller provides a number of user interface points through which user-supplied settings are input. The defrost type (internal/external) input 116 and the internal defrost parameters on input 118 have already been discussed. A user input 128 allows the user to specify the temperature set point to the adaptive tuning module 120 . The same information is supplied on user input 130 to the control block module 102 . The user can also interact directly with the control block module in a number of ways. User input 132 allows the user to switch the compressor on or off during defrost mode. User input 134 allows the user to specify the initial controller parameters, including the initial proportional constant K. The proportional constant K may thereafter be modified by the adaptive tuning module 120 . User input 136 allows the user to specify the pressure differential (dP) that the system uses as a set point.
In addition to these user inputs, several user inputs are provided for interacting with the signal conditioning module 110 . User input 138 selects the sensor mode of operation for the signal conditioning module. This will be described in more detail below. User input 140 allows the user to specify the sampling time used by the signal conditioning module. User input 142 allows the user to specify whether the controller shall be operated using temperature sensors only (T) or temperature and pressure sensors (T/P).
Referring now to FIG. 8, the signal conditioning module is shown in detail. The inputs (temperature and/or pressure sensors) are shown diagrammatically at 144 . These inputs are processed through analog to digital convertor 146 and then supplied to the control type selector 148 . Temperature readings from the temperature and/or pressure sensors are taken sequentially and supplied serially through the analog to digital convertor. The control type selector codes or stores the data so that pressure and temperature values are properly interpreted.
Digital filtering is then applied to the signal at 150 to remove spurious fluctuations and noise. Next, the data are checked in module 152 to ensure that all readings are within expected sensor range limits. This may be done by converting the digital count data to the corresponding temperature or pressure values and checking these values against the pre-stored sensor range limits. If the readings are not within sensor range an alarm signal is generated for output on output 154 .
Next a data manipulation operation is performed at 156 to supply the temperature and/or pressure data in the form selected by the sensor mode user input 138 . The current embodiment will selectively average the data or determine the minimum or maximum of the data (Min/Max/Avg). The Min/Max/Avg mode can be used to calculate the swing in pressure differential, or a conditioned temperature value. The average mode can be used to supply a conditioned temperature value. These are shown as outputs 158 and 160 , respectively.
FIG. 9 shows the control block module in greater detail. The conditioned temperature or pressure signal is fed to calculation module 162 that calculates the error between the actual temperature or pressure and the set point temperature or pressure. Module 162 also calculates the rate of change in those values.
The control block module is designed to update the operating state of the system on a periodic basis (every Tc seconds, nominally once every second). The Find Operating State module 164 performs this update function. The state diagram of FIG. 10 provides the details on how this is performed. Essentially, the operating state advances, from state to state, based on whether there is a sensor alarm (SA) present, whether there is a defrost status signal (DS) present and what the calculated error value is. The Find Operating State module 164 supplies the operating state parameter and the Pull Down Time parameter to the decision logic module 166 .
Referring to FIG. 10, the Find Operating State module 164 advances from state to state as follows. Beginning in the initial state 168 the module advances to the normal operating state 170 after initialization. It remains in that state until certain conditions are met. FIG. 10 shows by label arrows what conditions are required to cycle from the normal operating state 170 to the defrost state 172 ; to the pull down state 174 ; to the sensor alarm pull down state 176 ; to the sensor alarm operating state 178 and to the sensor alarm defrost state 180 .
The decision logic module 166 (FIG. 9) determines the duty cycle of the variable duty cycle signal. This is output on lead 182 , designated % Loading. The decision logic module also generates the compressor ON/OFF signal on lead 184 . The actual decision logic will be described below in connection with FIG. 11 . The decision logic module is form of proportional integral (PI) control that is based on an adaptively calculated cycle time T cyc . This cycle time is calculated by the calculation module 186 based on a calculated error value generated by module 188 . Referring back to FIG. 6, the conditioned pressure differential signal on lead 122 (Cond dP) is supplied to the Calculate Error module 188 (FIG. 9) along with the pressure differential set point value as supplied through user input 136 (FIG. 6 ). The difference between actual and set point pressure differentials is calculated by module 188 and fed to the calculation module 186 . The adaptive cycle time T cyc is a function of the pressure differential error and the operating state as determined by the find operating state module 164 according to the following calculation:
T cyc(new) =T cyc(old) +K c * Error (1)
where:
K c : proportional constant; and
Error: (actual-set point) suction pressure swing.
The presently preferred PI control algorithm implemented by the decision logic module 166 is illustrated in FIG. 11 . The routine begins at step 200 by reading the user supplied parameters K, T i , T c and S t . See FIG. 6 for a description of these user supplied values. The constant K p is calculated as being equal to the initially supplied value K; and the constant K i is calculated as the product of the initially supplied constant K and the ratio T c /T i .
Next, at step 202 a decision is made whether the absolute value of the error between set point temperature and conditioned temperature (on lead 190 , FIG. 9) is greater than 5° F. If so, the constant K p is set equal to zero in step 204 . If not, the routine simply proceeds to step 206 where a new loading percent value is calculated as described by the equation in step 206 of FIG. 11 . If the load percent is greater than 100 (step 208 ), then the load percent is set equal to 100% at step 210 . If the load percent is not greater than 100% but is less than 0% (step 212 ) the load percent is set equal to 0% at step 214 . If the load percent is between the 0% and 100% limits, the load percent is set equal to the new load percent at step 216 .
The variable duty cycle control signal generated by the controller can take several forms. FIGS. 12 and 13 give two examples. FIG. 12 shows the variable duty cycle signal in which the duty cycle varies, but the frequency remains constant. In FIG. 12, note that the cycle time, indicated by hash marks 220 , are equally spaced. By comparison, FIG. 13 illustrates the variable duty cycle signal wherein the frequency is also varied. In FIG. 13, note that the hash marks 220 are not equally spaced. Rather, the waveform exhibits regions of constant frequency, regions of increasing frequency and regions of decreasing frequency. The variable frequency illustrated in FIG. 13 is the result of the adaptive modulation of the cycle time T cyc .
FIG. 14 graphically shows the benefits that the control system of the invention has in maintaining tighter temperature control and higher suction pressure with improved system efficiency. Note how the temperature curve 222 of the invention exhibits considerably less fluctuation than the corresponding temperature curve 224 of a conventional controller. Similarly, note that the pressure curve 226 of the invention has a baseline well above that of pressure curve 228 of the conventional controller. Also, the peak-to-peak fluctuation in pressure exhibited by the invention (curve 226 ) is much smaller than that of the conventional controller (curve 228 ).
The controller of the invention operates at a rate that is at least four times faster (typically on the order of at least eight times faster) than the thermal time constant of the load. In the presently preferred embodiment the cycle time of the variable duty cycle signal is about eight times shorter than the time constant of the load. By way of non-limiting example, the cycle time of the variable duty cycle signal might be on the order of 10 to 15 seconds, whereas the time constant of the system being cooled might be on the order of 1 to 3 minutes. The thermal time constant of a system being cooled is generally dictated by physical or thermodynamic properties of the system. Although various models can be used to describe the physical or thermodynamic response of a heating or cooling system, the following analysis will demonstrates the principle.
Modeling the Thermal Time Constant of the System Being Cooled
One can model the temperature change across the evaporator coil of a refrigeration system or heat pump as a first order system, wherein the temperature change may be modeled according to the following equation:
ΔT=ΔT ss [1−exp(− t/γ )]+ ΔT 0 exp(−τ/γ).
where:
ΔT=air temperature change across coil
ΔT ss =steady state air temperature change across coil
ΔT 0 =air temperature change across the coil at time zero
t=time
γ=time constant of coil.
The transient capacity of the unit can be obtained by multiplying the above equation by the air mass flow rate (m) and specific heat at constant pressure (C p ) and integrating with respect to time.
Generally, it is the removal of the refrigerant from the evaporator that controls the time required to reach steady state operating condition, and thus the steady state temperature change across the condenser coil. If desired, the system can be modeled using two time constants, one based on the mass of the coil and another based on the time required to get the excess refrigerant from the evaporator into the rest of the system. In addition, it may also be desirable to take into account, as a further time delay, the time lag due to the large physical distance between evaporator and condenser coils in some systems.
The thermal response of the evaporator coil may be modeled by the following equation:
=½[(1 −e 1/γ1 )+(1 −e 1/γ2 )]
where:
=temperature change across coil/steady state temperature change across coil
t=time
γ 1 =time constant based on mass of coil
γ 2 =time constant based on time required to remove excess refrigerant from evaporator
In practice, the controller of the invention cycles at a rate significantly faster than conventional controllers. This is because the conventional controller cycles on and off in direct response to the comparison of actual and set-point temperatures (or pressures). In other words, the conventional controller cycles on when there is demand for cooling, and cycles off when the error between actual and set-point temperature is below a predetermined limit. Thus the on-off cycle of the conventional controller is very highly dependent on the time constant of the system being cooled.
In contrast, the controller of the invention cycles on and off at a rate dictated by calculated values that are not directly tied to the instantaneous relation between actual and set-point temperatures or pressures. Rather, the cycle time is dictated by both the cycle rate and the duty cycle of the variable duty cycle signal supplied by the controller. Notably, the point at which the controller cycles from on to off in each cycle is not necessarily the point at which the demand for cooling has been met, but rather the point dictated by the duty cycle needed to meet the demand.
Adaptive Tuning
The controller Geneva described above can be configured to perform a classic control algorithm, such as a conventional proportional-integral-derivative (PID) control algorithm. In the conventional configuration the user would typically need to set the control parameters through suitable programming. The controller may also be of an adaptive type, described here, to eliminate the need for the user to determine and program the proper control parameters.
Thus, one important advantage of the adaptive controller is its ability to perform adaptive tuning. In general, tuning involves selecting the appropriate control parameters so that the closed loop system is stable over a wide range of operating conditions, responds quickly to reduce the effect of disturbance on the control loop and does not cause excessive wear of mechanical components through continuous cycling. These are often mutually exclusive criteria, and a compromise must generally be made. In FIG. 18 (and also FIG. 6) there are two basic control loops: the refrigeration control loop and the adaptive tuning loop. The refrigeration control loop is administered by control block module 102 ; the adaptive loop is administered by adaptive tuning module 120 . Details of the adaptive tuning module 120 are shown in FIGS. 15, 16 a- 16 c and 17 . The presently preferred adaptive tuning module uses a fuzzy logic control algorithm that will be described in connection with FIGS. 18-20.
Referring to FIG. 15, the adaptive tuning module performs basically three functions. First, it decides whether to perform adaptive tuning. This is handled by module 240 . Second, it gathers the needed parameters for performing adaptive tuning. This is handled by module 242 . Third, it calculates the adaptive gain used by the control loop. This is handled by module 244 .
Module 240 bases the decision on whether to start tuning upon two factors: the current operating state of the system and the control set point. The flowchart of FIG. 16 a shows the steps involved in this decision. Module 242 integrates key parameters needed for the calculations performed by module 244 . Essentially, module 242 inputs the percent loading, the temperature and pressure values and the set point temperature. It outputs the following data: S_ER (the total number of conditioned temperature and pressure data points that are within 0.5 degrees or 1 Psig of the set point value), S_Close (the total number of percent loading data points that goes to zero percent during a given sampling interval, e.g. 30 min.), S_Open (the total number of percent loading data points that goes to 100% in the sampling interval) and SSLP (a moving average or rolling average of the percent loading during the sampling interval). Module 242 is responsive to a tuning flag that is set by module 240 . Module 242 performs the integration of these key parameters when signaled to do so by the tuning flag. FIG. 16 b shows the steps involved in performing integration of these key parameters.
Finally, the calculation block takes the data supplied by module 242 and calculates the adaptive gain using the process illustrated in FIG. 16 c.
The adaptive tuning module 120 will cycle through various operating states, depending on the state of a timer. FIG. 17 is a state diagram showing how the presently preferred embodiment will function. Note that the sequence transitions from the initialization mode to either the integration mode or the no tuning mode, depending on whether the tuning flag has been set. Once in the integration mode, the system performs integration until the timer lapses (nominally 30 minutes), whereupon the calculation mode is entered. Once the calculations are completed the timer is reset and the system returns to the initialization mode.
The block diagram of the adaptive scheme is shown in FIG. 18 . There are two basic loops—The first one is the PID control loop 260 that runs every “dt” second and the second is the adaptive loop 262 that runs every “ta” second. When the control system starts, the PID control loop 260 uses a default value of gain (K) to calculate the control output. The adaptive loop 262 , checks the error e(t) 264 every “ta” seconds 266 (preferably less than 0.2 * dt seconds). At module 268 if the absolute value of error, e(t), is less than desired offset (OS), a counter Er_new is incremented. The Offset (OS) is the acceptable steady-state error (e.g. for temperature control it may be +/1° F.). This checking process continues for “tsum” seconds 270 (preferably 200 to 500 times dt seconds). After “tsum” seconds 270 , the value Er_new is converted into percentage (Er_new% 272 ). The parameter Er_new% 272 indicates the percentage of sampled e(t) that was within accepted offset (OS) for “tsum” time. In other words, it is a measure of how well the control variable was controlled for past “tsum” seconds. A value of 100% means “tight” control and 0% means “poor” control. Whenever Er_new% is 100%, the gain remains substantially unchanged as it indicates tighter control. However, if Er_new happens to be between 0 and 100%, adaptive fuzzy-logic algorithm module 274 calculates a new gain (K_new 276 ) that is used for next “tsum” seconds by the control algorithm module 278 .
In the preferred embodiment, there is one output and two inputs to the fuzzy-logic algorithm module 274 . The output is the new gain (K_new) calculated using the input, Er_new%, and a variable, Dir, defined as follows:
Dir= Sign[( ER -new%− ER _old%)*( K _new− K _old)] (2)
where:
Sign stands for the sign (+ve, −ve or zero) of the term inside the bracket;
Ernew% is the percentage of e(t) that is within the offset for past “tsum” seconds;
Er_old% is the value of Er_new% in “(tsum−1)” iteration;
K_new is the gain used in “tsum” time; and
K_old is the gain in (tsum−1) time.
For example, suppose the controller starts at 0 seconds with a default value of K=10 and, ta=1 seconds, tsum=1000 seconds and OS=1. Suppose 600 e(t) data out of a possible 1000 data was within the offset. Therefore, after 1000 sec. Er_new%=60 (i.e., 600/1000*100), K_new=10. Er_old% and K_old is set to zero when the adaptive fuzzy-logic algorithm module 274 is used the first time. Plugging these numbers in Eq.(2) gives the sign of the variable “Dir” as positive. Accordingly, the inputs to the adaptive fuzzy-logic module 274 for the first iteration are respectively, Er_new%=60 and Dir=+ve.
The next step is to perform fuzzification of these inputs into fuzzy inputs by using membership functions.
Fuzzification
A membership function is a mapping between the universe of discourse (x-axis) and the grade space (y-axis). The universe of discourse is the range of possible values for the inputs or outputs. For ER_new% it is preferably from 0 to 100. The value in the grade space typically ranges from 0 to 1 and is called a fuzzy input, truth value, or a degree of membership. FIG. 19 shows graph 300 which contains the membership functions for the input, Er_new%. Er_new% is divided into three linguistic variables—LARGE ( 304 ), MEDIUM ( 306 ) AND SMALL ( 308 ). For Er_new%=60, the fuzzy inputs (or degree of membership function) are −0.25 of LARGE and 0.75 of MEDIUM. The input variable “Dir” is well defined (+ve, −ve or zero) and thus does not require a membership function in this application. The next step is to create the “Truth Table” or Rule Evaluation.
Rule Evaluation
Rule evaluation takes the fuzzy inputs from the fuzzification step and the rules from the knowledge base and calculates fuzzy outputs. FIG. 20 shows the rules as truth table. For the first column and first row, the rule is: “IF ER_new% is LARGE AND Dir is NEGATIVE THEN New Gain is NO CHANGE (NC)” (i.e. if the percentage of e(t) data that is within the offset (OS) for last “tsum” seconds is LARGE and the direction (DIR) is NEGATIVE/ZERO then do not change the existing K value (NO CHANGE)).
In the example, because ER_new% has fuzzy inputs LARGE (0.25) AND MEDIUM (0.75) with POSITIVE Dir, the rules that will be used are:
IF ER_new% is LARGE (0.25) AND Dir is POSITIVE THEN New Gain is NO CHANGE (NC=1)
IF ER_new% is MEDIUM (0.75) AND Dir is POSITIVE THEN New Gain is POSITIVE SMALL CHANGE (PSC=1.2)
Defuzzification
Finally, the defuzzification process converts the fuzzy outputs from the rule evaluation step into the final output by using Graph 310 of FIG. 21 . Graph 310 , uses the following labels =“NBC” for negative big change; “NSC” for negative small change; “NC” for no change; “PSC” for positive small change; and PBC for positive big change. The Center of Gravity or centroid method is used in the preferred embodiment for defuzzification. The output membership function for change in gain is shown in FIG. 21 .
The centroid (the Fuzzy-Logic Output) is calculated as: Centroid = K_new · [ ∑ μ ( x ) · x
all . x ∑ μ ( x )
all . x ]
where:
(x) is the fuzzy output value for universe of discourse value x. In our example, the output (K_new) becomes Output = 10 · [ 0.25 ( 1 ) + 0.75 ( 1.2 ) 0.25 + 0.75 ] ≈ 11.50
Once the three steps of fuzzification, rule evaluation, and defuzzification are finished and the output has been calculated, the process is repeated again for new set of Er_new%.
In the above example, after the first 1000 sec, the adaptive algorithm calculates a new gain of K_new=11.50. This new gain is used for the next 1000 sec (i.e. from t=1000 to 2000 sec in real time) by the PID control loop. At t=1001 sec, counter Er_new is set to zero to perform counting for the next 1000 seconds. At the end of another 1000 seconds (ie. at t=2000 seconds), Er_new% is calculated again.
Suppose this time, Er_new% happens to be 25. This means, by changing K from 10 to 11.5, the control became worse. Therefore, it would be better to change gain in the other direction, i.e., decrease the gain rather than increase. Thus, at t=2000 sec, Er_new%=25, Er_old%=60 (previous value of Er_new%), K_new=11.5 and K_old=10 (previous value of K). Applying Eq.(2), a negative “Dir” is obtained. With Er_new% of 25 and Dir=Negative, the fuzzy-logic calculation is performed again to calculate a new gain for the next 1000 seconds. The new value of gain is K_new=7.76 and is used from t=2000 to 3000 seconds by the PID Loop.
Suppose for the third iteration, i.e., from t=2000 to 3000 seconds, Er_new% comes out to be 95% (which represents tighter control). Performing the same fuzzy-logic operation gives the same value of K_new, and the gain remains unchanged until Er_new% again degrades.
Exemplary Applications
Both pulse width modulated (PWM) Compressors and electronic stepper regulator (ESR) Valves can be used to control evaporator temperature/pressure or evaporator cooling fluid (air or water) temperature. The former controls by modulating the refrigerant flow and the latter restricts the suction side to control the flow. Referring back to FIG. 18, the block diagram of the control system for such an actuator working in a refrigeration system 279 is shown. In FIG. 18 one and preferably up to four temperatures of evaporator cooling fluid or one evaporator suction pressure (generally shown at 282 ) is sampled every dt seconds. A sampling time of dt=10 seconds was found to be optimum for both the applications. After processing by the analog to digital module 284 , the sampled signal is then reduced to one number by taking the average or the minimum or the maximum of the four temperatures depending on the system configuration or the user preference at module 286 . Typically, in a single actuator (PWM/ESR) systems where the complete evaporator coil goes into defrost at one time, averaging of control signal is preferred. In a multiple evaporator-single actuator system where defrost of evaporator coils does not occur at the same time, minimum is the preferred mode. The value obtained after avg/min/max is called conditioned signal. At comparison module 288 this is compared with the desired set point to calculate the error, e(t).
The control algorithm used in the loop is a Proportion-integral (PI) control technique (PID). The PI algorithm calculates the valve position (0-100%) in case of ESR or calculates the percentage loading (0 to 100%) in case of PWM compressor. A typical integral reset time, Ti, for both the actuators is 60 seconds. The gain is tuned adaptively by the adaptive loop. The adaptive algorithm is turned off in the preferred embodiment whenever: the system is in defrost; is going through pull-down; there a big set point change; sensor failure has been detected; or any other system failure is detected.
Consequently, the adaptive algorithm is typically used when the system is working under normal mode. The time “ta” preferably used is about 1 seconds and “tsum” is about 1800 seconds (30 minutes). Diagnostics Related to PWM Compressor/ESR Valves:
Referring to FIG. 22, a discharge cooling fluid temperature sensor 312 (Ta), an evaporator coil inlet temperature sensor 314 (Ti) and an evaporator coil exit temperature sensor 316 (To) can provide diagnostic features for the evaporator control using PWM/ESR. The Inlet temperature sensor 314 can be anywhere in evaporator coil 318 . However, the preferred location is about one third of the total evaporator length from the evaporator coil distributor 320 .
Using these three temperature sensors, system learning can be performed that can be used for diagnostics. For example, diagnostics can be performed for ESR/PWM when it is used in a single evaporator along with an expansion valve. In this example, the following variables are tracked every “tsum” second in the adaptive loop. The variables can be integrated just after ER_new integration is done in the adaptive loop.
N-Close: Number of times Valve position /PWM loading was 0%.
N-Open: Number of times Valve position/PWM loading was 100%.
MAVP: The moving average of the Valve position /PWM loading for “tsum” seconds.
SSLP: The steady-state Valve position /PWM loading is set equal to MAVP if for the “tsum” duration ER_new% is greater than 50%.
dT: Moving average of the difference between Ta and Ti (Ta−Ti).
SH: Moving average of the difference between To and Ti (To−Ti) in the said duration. This is approximately the evaporator superheat.
N_FL: Number of times To was less than Ti during the said duration, i.e., “tsum” seconds. This number will indicate how much the expansion valve is flooding the evaporator.
In addition, Pull-down time after defrost, tpd, is also learnt. Based on these variables, the following diagnostics are performed: temperature sensor failure; degraded expansion valve; degraded ESR valve/PWM Compressor; oversized ESR/PWM; undersized ESR/PWM; and no air flow.
Temperature Sensor Failure
Failures of temperature sensors are detected by checking whether the temperature reading falls within the expected range. If PWM/ESR is controlled using Ta as the control variable, then when it fails, the control is done as follows. The above said actuator is controlled based on Ti, or the Ta values are estimated using the learned dT (i.e., add dT to Ti value to estimate Ta). During pull down, the valve/PWM can be set to full-open/load for the learned pull-down time (tpd). If Ti also fails at the same time or is not available, the actuator is opened 100% during pull down time and then set to steady-state loading percent (SSLP) after pull-down-time. An alarm is sent to the supervisor upon such a condition.
Degraded Expansion Valve
If an expansion valve sticks or is off-tuned or is undersized/oversized, the following combinations of the tracked variable can be used to diagnose such problems. N_FL>50% and ER_new%>10% indicate the expansion valve is stuck open or is off-tuned or may be even oversized and thus is flooding the evaporator coil. An alarm is sent upon such a condition. Moreover, SH>20 and N_FL=0% indicate an off-tuned expansion valve or an undersized valve or the valve is stuck closed.
Degraded ESR Valve/PWM Compressor
A degraded ESR is one that misses steps or is stuck. A degraded PWM Compressor is one whose solenoid is stuck closed or stuck open. These problems are detected in a configuration where defrost is performed by setting the ESR/PWM to 0%. The problem is detected as follows.
If ER_new%>50% before defrost and during defrost Ti<32□ F. and SH>5□ F., then the valve is determined to be missing steps. Accordingly, the valve is closed by another 100% and if Ti and SH remain the same then this is highly indicative that the valve is stuck.
If ER_new%=0 and N_Close is 100% and Ti<32 F. and SH>5 F. then PWM/ESR is determined to be stuck open. If ER_new%=0 and N_Open is 100% and Ti>32 F. and SH>5 F. then PWM/ESR is determined to be stuck closed.
Over-sized ESR/PWM
If N_Close>90% and 30%<ER_new%<100%, then an alarm is sent for oversized valve/PWM Compressor.
Under-sized ESR/PWM
If N_Open>90% and ER_new%=0 and SH>5, then an alarm is sent for undersized valve/PWM Compressor.
No Air Flow
If N_Open=100%, ER_new%=0, SH<5 F. and Ti<25 F and N_FL>50%, then either the air is blocked or the fans are not working properly.
Additionally, these diagnostic strategies can also be applied to an electronic expansion valve controller.
The embodiments which have been set forth above were for the purpose of illustration and were not intended to limit the invention. It will be appreciated by those skilled in the art that various changes and modifications may be made to the embodiments discussed in this specification without departing from the spirit and scope of the invention as defined by the appended claims.
APPENDIX
Pseudocode for Performing Signal Conditioning
Repeat the following every Ts Seconds:
Read User Inputs:
Sampling Time (Ts)
Control Type (P or T)
Sensor Mode (Avg/Min/Max)
Perform Analog to Digital Conversion (ADC)
on all (four) Temp. Sensor Channels
output data as Counts
Digitally Filter Counts
Ynew=0.75 Yold+0.25 Counts
output data as Filtered Counts
Convert Filtered Counts to Deg F.
Test if at least one Sensor is within normal operating limits
e.g. within −40 and +90 F.
If none are within limit—Set Sensor Alarm to TRUE
Else Perform Avg/Min/Max operation based on Sensor Mode
If Control Type is NOT a T/P Control Type
Then End Signal Conditioning Routine (until next Ts cycle)
Else (Control Type is T/P) Do the Following:
Perform ADC on Pressure Sensor Channel
output data as Counts
Digitally Filter Counts
Ynew=0.75 Yold+0.25 Counts
output data as Filtered Counts
Convert Filtered Counts to Psig
Test if pressure Sensor is within normal operating limits
e.g. within 0 and +200
If not within limit:
Set dP=dP Set Pt.
Else:
Calculate dP=Pmax-Pmin
Set Sensor Alarm to Conditioned T/dP
End Signal Conditioning Routine (until next Ts cycle) | A diagnostic system includes a controller adapted for coupling to a compressor or electronic stepper regulator valve. The controller produces a variable duty cycle control signal to adjust the capacity of the compressor or valve position of the electronic stepper regulator valve as a function of demand for cooling. The diagnostic system further includes a diagnostic module coupled to the controller for monitoring and comparing the duty cycle with at least one predetermined fault value indicative of a system fault condition and an alert module responsive to the diagnostic module for issuing an alert signal when the duty cycle bears a predetermined relationship to the fault value. | 5 |
FIELD OF THE INVENTION
The present invention relates to a box constructed from a flat blank which is cut and folded. More particularly, the invention relates to a box with a hinged portion for opening and reclosing the box, and to a flat blank used to construct such a box.
BACKGROUND OF THE INVENTION
There are numerous known boxes with hinged portions for opening and reclosing. These boxes can be described generally as having four sides and two ends, the reclosable portion usually provided at one of the ends of the box.
One of the simplest types of reclosable boxes is the box with a perforated end flap like the one disclosed in U.S. Pat. No. 4,142,635 to Capo et al. Such flaps are usually provided with an edge tab of some kind which is insertable in a slot to thereby reclose the box after the perforated flap is torn open.
Some other known boxes are more elaborate, having relatively large hinged covers with skirts or depending flanges which cover the box on its sides, unlike a simple flap. Examples of these types of boxes can be found in U.S. Pat. No. 4,048,052 to Tolaas; U.S. Pat. No. 4,421,236 to Lowe; and U.S. Pat. No. 4,570,790 to Turnage.
Still another type of reclosable box is shown in U.S. Pat. No. 4,733,796 to Halverstadt et al. This last type is similar to the large hinged covers with skirts, but here the skirts of the cover actually form a portion of the sides of the box.
Each type of box has its advantages and disadvantages, usually low cost of manufacture or security of the closure, one of these being sacrificed to provide the other. However, aside from these considerations, some types of boxes are better suited for particular products. For example, the simple end flap is widely used in boxes containing pourable material, whereas the larger hinged covers are more typically used in boxes containing larger solid contents such as cigarettes, or contents which are not pourable such as ice cream.
An important feature of all of the boxes mentioned above is a locking means of some type, that is some means to keep the hinged closable portion of the box securely closed until it is intentionally reopened. As previously mentioned, in the case of the simple flap, the locking means is usually an end tab insertable into a slot. In the case of the larger hinged covers, known locking means include a slit or cut line in the front skirt of the cover which engages with a locking flange in the form of a tab extending from a side of the box as shown in U.S. Pat. No. 4,048,052. Often the locking means is simply the surface contact (or nesting) of the skirt portion of the cover with the sides of the box as shown in U.S. Pat. Nos. 4,570,790 and 4,421,236. Still another locking means is shown in U.S. Pat. No. 4,733,796 where a pair of lips and grooves in the cover portion engage a similar pair of lips and grooves in a side portion of the box.
Each of these locking means has advantages and disadvantages often associated with the competing interests of security of locking and reduced cost of manufacture. Moreover, some locking means can be adapted only to particular box designs.
In some cases, the locking means have the disadvantage of being difficult to use. For example, the flap type opening with the slot insertable tab requires the user to deliberately insert the tab into the slot in order to provide any locking at all.
Of all of the known boxes discussed above, two have a particular advantage that the others do not have. The reclosable openings shown in U.S. Pat. Nos. 4,421,236 and 4,142,635 can both be described as pouring spouts. Although not disclosed in these patents, such a pouring spout opening can be used to dispense a measured portion of contents such as pasta. For example, spaghetti type pasta aligned in a box, perpendicular to the opening, will empty from the box in an amount directly proportional to the size of the opening. If the box is tilted to stop pouring before the pasta is completely free from the box, a measured portion can be obtained and removed manually. Unfortunately, of all the boxes discussed above, those with the pouring spout type opening provide the least secure locking means.
INCORPORATION BY REFERENCE
The complete disclosure of each of the U.S. Patents discussed above, namely U.S. Pat. Nos. 4,048,052; 4,142,635; 4,421,236; 4,570,790; and 4,733,796, is incorporated herein by reference.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a reclosable box which can be inexpensively produced from a flat blank by cutting and folding and where the reclosable portion of the box is provided with secure locking means.
It is also an object of this invention to provide a reclosable box where the locking means is easy to use and does not require deliberate difficult manipulation of the box by the user.
Yet another object of this invention is to provide a reclosable box where a plurality of locking means may be employed, either individually or in combination.
Still another object of this invention is to provide a reclosable box where the reclosable opening is configured such that measured portions of selected contents may be easily dispensed. Moreover, it is an object of the invention to provide means whereby the user can reconfigure the box opening to dispense single or double measured portions.
It is also an object of this invention to provide a reclosable box where the reclosable portion is provided with means to keep the box open as well as means to lock it shut.
Another object of this invention is to provide a flat blank in one piece, hinged in such a manner so as to provide accuracy in positioning of a flap when folded over onto the main body of the blank.
It is still another object of the invention to provide a blank, which after folding and gluing on one side, produces a box that has openings on its top and bottom, that can be used by box manufacturers and box users with little or no modification to existing machinery.
All of these objects are achieved by the box according to this invention which can be constructed from a single flat blank which is scored, perforated and die cut prior to folding. The blank comprises four side panels and two ends, the ends each comprising four flaps, one flap at each end of each side panel. Side panels and flaps are defined by fold lines.
In accordance with this invention, a reclosable opening is created at one end of the box by perforations, cuts or fold lines on three adjacent flaps and the side panels adjacent to these flaps. For example, in one embodiment, a central side panel is provided with an orthogonal fold line which joins angled perforated lines on each of the two panels adjacent to it, thus forming a substantially trapezoidal shape below the fold lines separating panels from flaps. The perforated lines on the adjacent side panels connect with cut or perforated lines on respective adjacent flaps. Thus, when the flaps and panels are folded on their fold lines and the box is constructed, a perforated hinged corner is created. In various embodiments of the invention, additional specified folds, cuts and perforations in the flaps and side panels provide a variety of locking means when the box is constructed from the blank.
In a preferred embodiment of the invention, an additional section of essentially trapezoidal shape is provided with cut and fold lines and glued to the three adjacent side panels in the vicinity of the above-mentioned orthogonal fold line. This additional section can be constructed from the same single blank by cutting and folding an extended portion of the above-mentioned flaps or can be a separate piece from a second blank. When the box is constructed, this additional section provides side panel coverage in the corner of the box when the cover is hinged open. Moreover, this additional section can be cut with shoulders or recesses in such a way that it interacts with mating shoulders or recesses cut in the hinged portion described above.
In yet another embodiment of the invention, perforations are provided on flaps to allow redimensioning of the box opening (mouth) by the user.
The box constructed according to this invention closes easily and stays closed until intentionally reopened because up to four different locking means can be employed. The mouth of the box can be redimensioned by the user to dispense measured portions of selected contents such as spaghetti. The box can be advantageously used to contain and dispense almost any dry product, e.g., pet food, bird seed, cereal, bread crumbs, prunes, raisins, small cookies, potato buds, noodles or any other pasta, rice, powdered detergent, powdered bleach, etc.
The blank for constructing the box can be made of any cardboard, laminated, waxed, foiled, coated, plain, thin or thick and also can be made of plastic material.
BRIEF DESCRIPTION OF THE DRAWINGS
With these and other objects in view, which will become apparent in the following detailed description, the present invention, which is shown by example only, will be clearly understood in connection with the accompanying drawing, in which:
FIG. 1 is a plan view of a flat blank used to construct a box according to a preferred embodiment of the invention;
FIG. 1A is a view similar to FIG. 1, but with additional section 12 folded down;
FIG. 2 is a view similar to FIG. 1 of an alternative embodiment of the invention where additional section 12 is in a slightly different position;
FIG. 2A is a view similar to FIG. 1A, but corresponding to the embodiment of FIG. 2;
FIG. 3 is a perspective view of one corner of a box constructed according to FIG. 1 and shown in an opened position;
FIG. 4 is a view similar to FIG. 3, but shown in the closed position;
FIG. 5 is a view similar to FIG. 3, but from a different angle;
FIG. 6 is a perspective view of a box in a stage of partial construction according to FIG. 1;
FIG. 7 is a perspective view from inside a closed box constructed according to FIG. 1;
FIG. 8 is a view similar to FIG. 3 but with a larger mouth;
FIG. 9 is a view similar to FIG. 3 but of an alternate embodiment constructed according to FIG. 10;
FIG. 10 is a view similar to FIG. 1 of an alternate embodiment of the invention;
FIG. 10A is a view similar to FIG. 10 but with additional section 12 folded down; and
FIG. 11 is a view similar to FIG. 1 showing a plurality of flat blanks to be cut from a single sheet in mass production.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, one embodiment of a blank 10 of the invention is shown. This blank may be constructed of various paperboard materials, including boxboard or any other semi-rigid packaging material. It is advantageous but not necessary that the blank be a single integral blank so that it can be cut from a continuous web of material, or stamped from a single sheet of suitable material. The blank 10 shown in FIG. 1 is designed to be erected into a generally rectangular box of the invention and is depicted in FIG. 1 showing what will become substantially the inside of the box of the presently described preferred embodiment invention.
It will be readily understood by those of ordinary skill in the art that the blank 10 is suitable for and intended to be cut or stamped from a continuous web or sheet, folded and glued, and subsequently filled and finally closed by high speed, automatic machines and automated processes designed for such purposes, as is customary. A box constructed from the blank 10 which is manually assembled, filled and closed is nonetheless considered well within the scope of the invention.
The preferred embodiment of blank 10 shown in FIG. 1 may be conveniently divided by fold lines into four side panels A,B,C,D, plus an extended portion E for gluing to side panel A, and eight flaps A',B',C',D' and A",B",C",D". The number and size of the flaps may be adjusted as will be discussed below and as would be known to one skilled in the art. When the box is folded, side panel A and extended portion E overlie each other to any suitable degree and are glued together. As illustrated in FIG. 1, the side panel A and extended portion E are coextensive in area.
The reclosable opening 20 of the box is constructed from a plurality of cuts and folds shown at the top of the blank in the vicinity of where the side panels B,C,D adjoin their adjacent flaps B',C',D'. It should be clear, however, that the reclosable opening 20 could be positioned at the bottom of the blank or on either side of the blank by appropriate scaling of dimensions, and such repositioning would involve no more than ordinary skill in the art.
It is helpful to refer also to FIGS. 3-8 while examining FIG. 1 to get a better idea how each cut and fold in FIG. 1 operates in the box after it is constructed from the blank.
In the preferred embodiment of FIG. 1, the hinged portion of the reclosable opening 20 is provided by fold line 31 in panel C. Fold line 31 may optionally be provided with a central rounded cut (or perforation) 26, the function of which is described below. Perforated or cut lines 32,33 in the adjacent side panels B,D adjoin fold line 31 and connect with the cut lines 42,43 respectively in the flaps B',D'. As shown in FIG. 1, the cut lines 42,43 are short to accommodate additional section 12 which is constructed partially from flaps B',D' and partially from portions extending therefrom. This additional section 12, however, could easily be constructed as an entirely separate piece, in which case the cut lines 42,43 would extend to the end of the flaps B',D', and the flaps would not be extended as shown, but would end at a point shown approximately by the dashed line T.
Either of the cut lines 42,43 may be provided with a rounded portion 46 which functions as an insertable tab locking means when the box is constructed. The rounded portion 46 also serves as a lifting tab for ease of opening the box. As shown in FIG. 1, cut line 43 is provided with such a rounded portion 46. Referring to FIGS. 3 and 4, one can readily see how cut line 42 then interacts with the rounded portion 46 of cut line 43 to act as a tab locking means when the box is constructed.
In the preferred embodiment, additional section 12 is constructed from the extended flaps B',D' so that it can be folded at fold lines 13,14 to assume its useful position as shown in FIG. 1A. In this illustrated position, additional section 12 is affixed to the side panels B,C,D, preferably by applying an adhesive material or glue along the cross-hatched area 11 as shown in FIG. 1. In practice, the manner and location of gluing will be determined by the particular gluing apparatus and processes employed, as is conventional. This preferred embodiment conserves materials and allows for more accurate registration of the additional section 12.
This additional section 12 is shown in the figures as substantially rectangular in shape. The purpose of the additional section 12 is essentially twofold, to provide a replacement portion for the side panels B,C,D beyond the hinge line 31 and the cut or perforated lines 32,33 after the box has been opened, so that the mouth 50 of the box is confined to the top of the box, as seen in, for example, FIGS. 3, 5, and 8, and also to provide additional locking and spring means for the reclosable opening 20. In some embodiments, all of these features may not be desired and additional section 12 can be reconfigured accordingly, as seen in, for example, FIGS. 9 and 10.
The rectangular shape of additional section 12 provides at least two additional benefits according to the invention. First, additional rigidity is provided to the side panels B,C,D so that heavier or denser products may be suitably packaged in the box for a given sheet thickness or "gauge." Second, because the glue area 11 may extend substantially across the entire widths of the side panels B,C,D, fine-grained material such as detergent may be prevented from leaking out through any separation which might otherwise exist between the side panels and the folded-down additional section 12. However, other shapes such as trapezoidal, would also be suitable, if the aforementioned additional benefits are not desired.
According to a preferred embodiment, additional section 12 provides two types of interactive locking means with a specific configuration of flap C' as shown in FIG. 1. According to the embodiment of FIG. 1, a lower portion of flap C' is cut with three openings, a slot-like opening 22 and two smaller edge (notch-like) openings 25. This portion of flap C' is folded so that it lies on the inside top surface of reclosable opening 20, as seen in FIGS. 5, 7, and 8. Additional section 12 is provided with shoulders 24 and tab 23 (optionally cut with a springing section 27) which interact with the cuts made in flap C'. When the reclosable opening 20 is closed, for example as shown in FIG. 7, the small edge openings 25 engage the shoulders 24 and the slot-like opening 22 engages the edge 21 of the tab 23 to provide positive locking in three places. It is important to note that this locking of the reclosable opening is virtually automatic as compared to an insertable tab flap which can also be provided by rounded portion 46 mentioned above.
The tab 23 uniquely provides a discernible tactile and audible "snap" action when reclosable opening 20 is closed and reopened. This snap action is caused or provided by the fact that the edge 21, in its relaxed condition, extends above the plane of the top surface of the box after the reclosable opening 20 is closed. Thus, the edge 21 is resiliently locked into the slot 22 of flap C'. As can be seen from the figures, the tab 23 bends inwardly as the reclosable opening 20 is closed, with the edge 21 snapping into the corresponding slot 22 only when the box is securely and adequately closed.
This bending action of tab 23 may be advantageously enhanced by optionally providing at least one horizontal score line 54 parallel to the tab edge 21, at a suitable position on the tab 23. A suitable position for this optional horizontal score line 54 for a cigarette box, by way of example only, would be nearer to tab edge 21 so that the tab 23 may flex over the relatively stiff cigarettes contained in the box.
The strength of the resilient action of tab 23 is determined by the width of the tab and its height, and the strength of the material of the blank, both in terms of its separation from the additional section 12 and how far above the plane of the top of the box the tab 23 extends when in its relaxed state. Another important aspect of the tab 23 is the undercut of edge 21 at the upper corners of the tab 23. This undercut may suitably be achieved in a variety of ways or shapes which will be readily apparent to those skilled in the art. The undercut serves to ensure that only the edge 21 of the tab 23 becomes lodged in the slot 22 of flap C; because the tab 23 is itself wider than the slot 22.
The angular cuts 29 at the top of flap C' shown in FIG. 1 are not necessary, but assist in the folding operations to assure that the flap C' does not interfere with the perforated section 28.
Because redundant locking structures are provided, it is possible to omit one of the particular locking structures yet retain most, if not all, of the advantages of the invention. For example, it may be desirable to omit the locking mechanism provided by the shoulders 24 and the small edge openings 25. The small size of the cut-out waste portions produced when the small edge openings 25 are stamped may present difficulties in the manufacturing process, and thus it may be desirable to eliminate the presence of waste particles of such small size. Furthermore, when the invention is applied to boxes made of light gauge stock, such as cigarette boxes, for example, the shoulders 24 and small edge opening 25 may not have sufficient rigidity to prove advantageous.
Additional section 12 can also be cut with a lower spring section 27 (preferably three orthogonal cut lines as shown in FIG. 1) which will interact with the optional rounded cut 26 made in fold 31 mentioned above. Operation of this spring is best seen in FIG. 8 where it functions to hold the reclosable opening 20 in an open position while dispensing contents from the box. Spring 27 also operates to hold the reclosable opening 20 in a closed position as seen in FIGS. 4 and 7, for example.
A perforated portion 28 can also be provided on additional section 12. This perforated portion should be placed so that it extends as shown in FIGS. 3 and 5. As can be seen in FIGS. 3 and 5, this portion 28 of section 12 can be removed by tearing the perforation and this will result in increasing the dimensions of the mouth 50 of the box. This feature is advantageously applied in boxes for pasta such as spaghetti or the like where the size of the mouth of the box can be a gauge of premeasured portions for dispensing. For example, the box can be dimensioned so that the mouth 50 with portion 28 in place dispenses a single serving of spaghetti and when portion 28 is removed by tearing the perforation, a double serving of such pasta is dispensed.
While it should be readily apparent to any person of ordinary skill in the art how the blank of FIG. 1 folds up, for the sake of completeness the following information is provided. The dotted lines separating the panels A,B,C,D and extended position E from one another are score lines on the side of the blank facing away from the reader, i.e., ultimately on the outside of the assembled box. The dotted lines separating the panels A,B,C,D from the bottom flaps A",B",C",D" and the top flaps A',B',C',D' are also score lines on the side of the blank facing away from the reader, as are the fold lines 13,14 of the additional section 12.
The horizontal dotted lines at approximately the midline of the additional section 12 (about even with the shoulders 24) are score lines on the side of the blank facing the reader. Once the additional section 12 is folded downwardly, these score lines are then positioned is substantial alignment with the tops of the side panels B, D. The hinge fold line 31 is similarly a score line on the side of the blank facing the reader, and remains permanently facing inside the assembled box so that the reclosable opening hingedly swings out and away from the assembled box.
The dotted line separating the perforated part 28 from the additional section 12 is preferably perforated through. All of the solid lines of FIG. 1 are out lines.
FIG. 2 shows an alternative embodiment of the inventive blank 10 for creating the box according to this invention. The main difference between FIGS. 1 and 2 is the placement of the fold lines 13,14 separating the additional section 12 from the adjacent flaps B',D'. Moreover, FIG. 2 helps to illustrate how one could construct additional section 12 as a separate piece cut from a different blank. For example if the fold lines 13,14 in FIG. 2 were cut lines, it will be readily seen how section 12 could be made from a separate blank. FIG. 2A shows section 12 folded into position, but also illustrates how section 12 would be placed if it were cut from a separate blank. Additional section 12 would, if cut or stamped from a separate blank, preferably be attached by adhesive means at more than one location such as is employed in the embodiment of FIG. 1.
FIG. 6 shows the blank of FIG. 1 folded into a partially constructed box. The flaps A',B',C',D' remain open so that the box can be filled with contents. The partially constructed box as shown in FIG. 6 is suitable for filling by automated filling apparatus and processes, as is customary. It should be noted that these flaps A',B',C',D' could be closed and the box could be filled from the other end by way of flaps A",B",C",D".
After the box is filled, two flaps A',C' are folded in and then the two remaining open flaps B',D' are folded in, the last flap to be folded being the one which contains the cut line with the rounded portion 46. The flaps are preferably glued or otherwise adhesively secured closed in a manner well known in the art.
When flap C' is folded over, it receives edge 21 of tab 23 in its slot-like opening 22 and its edge openings engage shoulders 24 until the box is opened by the user, as is apparent from FIGS. 5, 7, and 8.
After the box according to the preferred embodiment is constructed and filled, it appears to the consumer generally as depicted in FIG. 4. The lines 32,33 are preferably perforated lines so that the reclosable opening 20 will remain securely closed during shipping. As noted above, however, these lines could be cut lines rather than perforations provided the box is protected during shipping, e.g., by wrapping in plastic.
When the user first opens the box, the perforations in lines 32,33 are broken as shown generally in FIGS. 5 and 8. If line 26 is perforated rather than cut, the perforations of line 26 are also broken upon first opening.
Upon opening the box, mouth 50 is uncovered whereby the contents of the box may be poured out. If the contents are, for example, spaghetti type pasta, the size of the mouth 50 will determine the quantity of contents pouring forth from the mouth 50 when the box is tilted. As mentioned above, the mouth can be dimensioned to allow a measured single portion of contents to empty from the box at one time. The user then has the option of removing perforated portion 28 to allow dispensing of a larger, e.g., double, portion. Suitable instructions may be printed directly on the outwardly facing side of perforated portion 28 for ease and convenience of use.
In the open position, rounded portion 26 and spring 27 interact as shown in FIG. 8 to hold the reclosable portion 20 out of the way of contents emerging from the box through the open mouth 50.
After the box has been opened for the first time, it can be reclosed by moving the reclosable portion 20 back on its hinge 31. FIGS. 5, 7 and 8 show how up to four different locking means can be used to help keep the reclosable opening 20 in the closed position until intentionally reopened. First, rounded portion 26 and spring 27 interact. Second, shoulders 24 are received by openings 25. Third, slot 22 receives the edge 21 of tab 23. Fourth, the user can manually insert tab 46 under line 42. As will be readily seen, three of these four locking means are virtually automatic and do not require intentional action or manipulation on the part of the user, other than moving the reclosable portion 20 to its closed position.
It will also be apparent to those of ordinary skill upon inspection of FIGS. 5 and 8, for example, that the mouth 50 and the additional section 12 can be stamped or cut to form openings suited to a variety of different purposes. For example, the additional security provided by the shoulders 24 interacting with the small edge openings 25 may be deemed unnecessary in a cigarette package. Accordingly, the areas of the additional section 12 which form the sides of the assembled box may be partially eliminated, thus rendering access to the contents of the box easier, especially with ones fingers. This would be important in a cigarette package of generally reduced dimensions.
FIGS. 9, 10 and 10A show a third embodiment of the box and blank according to the invention. In this embodiment the hinged reclosable opening 20 is provided over a mouth of the box which extends along the top of the box and down around the box corner, partially on the side of the box. As will be seen, this configuration is especially useful for packaging "pourable" products such as detergents, because of the "side pour" opening.
In the embodiment of FIGS. 9, 10 and 10A, the reclosable opening 20 is formed with fold lines 31 on flap B, and 40 on flap D'. On panel C is a cut or perforated line 35 which adjoins cut or perforated lines 32,33, similar to the cut or perforated lines 32,33 shown in FIG. 1. Flat section 52 acts as a bias or spring member when the box is fully constructed. Perforated portion 28 is also reconfigured as best seen in FIG. 9. Here perforated portion 28 has a fold line which covers a corner of mouth 50. The box of FIG. 9 is assembled from the blank of FIGS. 10 and 10A by folding down and gluing additional section 12, then folding the side panels A,B,C,D and extended portion E and gluing side panel A to extended portion E, then folding inwardly the flaps A' and C', and finally folding and gluing flaps B' and D'. When so folded, overlapping section 56 serves to help keep fine-grained materials in the box.
As shown in FIG. 9, mouth 50 remains closed until perforated portion 28 is moved or removed. This additional closure or sealing portion 28 is advantageously used in the packaging of fine granular products such as detergents and the like. The extra protection provided by portion 28 assists in preventing spillage of product during shipping or while displayed on a retailer's shelves.
Two locking means are shown in FIGS. 9 and 10, namely the rounded portion 26 interacting with spring 52, plus the tension that is created when additional section 12 is glued down and folded. A snug friction fit is created under reclosable opening 20 which serves to hold opening 20 down and in its closed position.
As already noted, this last embodiment may be advantageously applied to package contents such as detergents where the double locking means shown is sufficient and where the removable configuration of perforated portion 28 is suitable for keeping the contents of the box from spilling out during shipping.
Although the invention is described and illustrated with reference to a plurality of embodiments thereof, it is to be expressly understood that it is in no way limited to the disclosure of such preferred embodiments but is capable of numerous modifications within the scope of the appended claims. | A reclosable box constructed from a flat blank which is cut and folded is featured by a number of different locking devices which may be used alone or in combination. The box can be constructed from a single flat blank and is easily mass produced, and is suited for automated assembly and filling operations. The reclosable portion of the box does not interfere with filling of the box in production. In addition to providing locking devices to keep the box closed until intentionally reopened, devices are disclosed which hold the reclosable portion of the box in an open position to dispense contents of the box. The mouth of the box can be configured to allow redimensioning of the mouth by the user so that selected contents can be dispensed in chosen measured portions. | 1 |
CROSS-REFERNCE TO RELATED APPLICATIONS
[0001] The present invention claims priority to U.S. Provisional Patent Application Ser. No. 60/637,015, filed on Dec. 17, 2004 by Robert K. Heck and Stephen A. Hazebrouck and entitled “Modular Implant System and Method with Diaphyseal Implant,” U.S. Provisional Patent Application Ser. No. 60/731,999, filed on Oct. 31, 2005 by Robert K. Heck and Stephen A. Hazebrouck, and entitled “Modular Diaphyseal and Collar Implant,” and U.S. Provisional Patent Application Ser. No. 60/732,402, filed on Oct. 31, 2005 by Robert K. Heck and Stephen A. Hazebrouck and entitled “Modular Implant System and Method with Diaphyseal Implant and Adapter,” all of which are incorporated by reference herein in their entireties.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to prosthetic joints and, more particularly, to modular orthopaedic lower extremity implant systems.
[0003] The knee joint basically consists of the bone interface of the distal end of the femur and the proximal end of the tibia. Appearing to cover or at least partially protect this interface is the patella which is a sesamoid bone within the tendon of the long muscle (quadriceps) on the front of the thigh. This tendon inserts into the tibial tuberosity and the posterior surface of the patella is smooth and glides over the femur.
[0004] The distal femur is configured with two knob like processes (the medial condyle and the lateral condyle) which are substantially smooth and which articulate with the medial plateau and the lateral plateau of the tibia, respectively. The plateaus of the tibia are substantially smooth and slightly cupped thereby providing a slight receptacle for receipt of the femoral condyles.
[0005] The hip joint consists of the bone interface of the proximal end of the femur and the acetabulum of the hipbone. The proximal femur is configured with a ball-shaped head, which is received within and articulates against the cup-shaped cavity defined by the acetabulum.
[0006] When the knee or hip joint is damaged whether as a result of an accident or illness, a prosthetic replacement of the damaged joint may be necessary to relieve pain and to restore normal use to the joint. Typically the entire joint is replaced by means of a surgical procedure, which involves removal of the surfaces of the corresponding damaged bones and replacement of these surfaces with prosthetic implants. This replacement of a native joint of the leg with a prosthetic joint is referred to as primary total-knee arthroplasty and primary total-hip arthroplasty.
[0007] On occasion, the primary prosthesis fails. Failure can result from many causes, including wear, aseptic loosening, osteolysis, ligamentous instability, arthrofibrosis and patellofemoral complications. When the failure is debilitating, revision surgery may be necessary. In a revision, the primary prosthesis is removed and replaced with components of a revision prosthetic system.
[0008] Implant systems for both primary and revision applications are available from a variety of manufacturers, including DePuy Orthopaedics, Inc. of Warsaw, Ind. DePuy and others offer several different systems for both primary and revision applications. For example, DePuy Orthopaedics offers the P.F.C. SIGMA® Knee System, the LCS® Total Knee System, and the S-ROM Modular Total Knee System. Each of these orthopaedic knee systems includes several components, some appropriate for use in primary knee arthroplasty and some appropriate for use in revision surgery.
[0009] DePuy Orthopaedics also offers other orthopaedic implant systems for other applications. One such system is the LPS System. The LPS System is provided for use in cases of neoplastic diseases (e.g., osteosarcomas, chrondrosarcomas, giant cell tumors, bone tumors) requiring extensive resections and replacements of the proximal and/or distal femur, severe trauma, disease (e.g., avascular necrosis, osteoarthritis and inflammatory joint disease requiring extensive resection and replacement of the proximal and/or distal femur), and resection cases requiring extensive resection and replacement of the proximal, distal or total femur or proximal tibia (e.g., end-stage revision). Any of these conditions or a combination thereof can lead to significant amounts of bone loss. The LPS System provides components that can replace all or significant portions of a particular bone, such as the femur or tibia. The DePuy LPS System is described more fully in U.S. patent application Ser. No. 10/135,791, entitled “Modular Limb Preservation System”, filed Apr. 30, 2002 by Hazebrouck et al., U.S. Pat. Publication No. US2003/0204267A1 (published Oct. 30, 2003) which is incorporated by reference herein in its entirety. Other companies also offer systems for similar indications.
[0010] The LPS system provides a comprehensive set of modular implants capable of addressing a wide range of orthopaedic conditions. Components of the LPS system can be combined in a variety of ways to account for variations in patient anatomy and differences in the amount of native bone remaining. As disclosed in U.S. Pat. Publication No. US2003/0204267A1, the modular components can be combined to replace the proximal or distal femur, total femur, proximal tibia or the mid-shaft of a long bone. Similar systems can be used with other long bones, such as the bones of the upper arm.
[0011] Many of the combinations of components possible with the LPS system include stem components that are configured for implantation within the intramedullary canal of the remaining bone. Metaphyseal sleeves are available for use in the LPS system, as disclosed, for example, in U.S. patent application Ser. No. 10/817,051, entitled “Modular Implant System with Fully Porous Coated Sleeve”, filed on Apr. 2, 2004 by Goodfried, Hazebrouck, Lester and Brown (U.S. Pat. Publication No. 2005/0107883A1), which is incorporated by reference herein in its entirety. However, in some instances, the stem components must be used with implant components that have replaced the entire articulating portion of the bone and the metaphysis of the bone. In some indications, the remaining native bone comprises the diaphysis or shaft of the long bone, and a metaphyseal sleeve cannot be used.
[0012] An example of a long bone is illustrated in FIG. 1 ; in FIG. 1 , the bone 10 is the femur. FIG. 2 illustrates the femur of FIG. 1 after the distal articulating end 12 and metaphysis 14 of the bone 10 have been removed due to neoplastic disease, trauma, disease or as part of an end-stage revision. The diaphysis of the bone is illustrated at 16 in FIGS. 1-2 .
[0013] As shown in FIG. 2 , the intramedullary canal 18 of the diaphysis 16 of the long bone 10 generally tapers, while the implant stem extensions 20 generally have parallel sides, such as those shown at 22 , 24 . As a result, the implant stem extension 20 frequently contacts the native bone tissue at the free end or tip 28 of the stem extension 20 , while leaving gaps 30 along much of the length of the stem extension 20 . Although these gaps 30 could be filled with bone cement, for optimal fixation it is desirable to use porous coated stem extensions. Such porous coated stem extensions tend to bind before becoming fully seated. Consequently, in cases where the stem extension is porous coated to encourage bone ingrowth, the bone ingrowth is frequently limited to the free end 28 of the stem. With bone ingrowth limited to the free end of the stem extension, there is stress shielding of the bone surrounding the remainder of the stem extension, and a long lever arm is created; both of these effects can lead to early loosening of the implant. Additionally, when significant ingrowth does occur and the stem extension must subsequently be removed, the procedure can be difficult.
SUMMARY OF THE INVENTION
[0014] The present invention addresses the need for an implant system that can be effectively used in the diaphyseal region of a long bone and for a surgical method for implanting a system in the diaphyseal region of a long bone.
[0015] In one aspect, the present invention addresses this need by providing a modular orthopaedic implant system comprising a diaphyseal component and a collar component. The diaphyseal component includes a first end, a second end and a tapered outer surface. The first end has a post and the second end has a bore co-axial with the post of the first end. A longitudinal axis extends from the first end to the second end. The longitudinal axis extends through the post at the first end and the bore at the second end. The tapered outer surface is between the first end and the second end, and has a maximum outer diameter at the first end and a minimum outer diameter at the second end. At least part of the tapered outer surface is porous. The collar component includes a first end, a second end and a substantially cylindrical portion between the first end and the second end. The first end of the collar component has a post, and the second end has a bore co-axial with the post of the first end. A longitudinal axis extends from the first end to the second end; the longitudinal axis extends through the post at the first end and the bore at the second end. The substantially cylindrical portion surrounds at least a portion of the bore at the second end and includes an annular surface disposed perpendicular to the longitudinal axis of the collar component at the second end of the collar component. The annular surface has a maximum outer diameter. The post of the diaphyseal component and the bore of the collar component are sized and shaped so that the diaphyseal component and the collar component can be assembled and locked together by inserting the post of the diaphyseal component into the bore of the collar component.
[0016] In another aspect, the present invention addresses this need by providing an orthopaedic implant system for replacing a portion of a long bone. The long bone has an articulation portion, a diaphysis and an intramedullary canal. The kit includes a plurality of articulation components, a plurality of modular stems, a plurality of modular diaphyseal implant components, and a plurality of collar components. Each articulation component is shaped and sized to replace the articulation portion of the long bone, and includes a tapered bore having a first size. The modular stems are to be received in the intramedullary canal of the long bone. Each stem has a free end and an opposite end capable of being connected to another implant component. The modular diaphyseal implant components are capable of being connected to the modular stems. Each diaphyseal implant component includes a first end, a second end and a tapered outer surface. The first end has a tapered post and the second end is provided for connection to a selected modular stem. A longitudinal axis extends between the first end and the second end of each diaphyseal implant component. The tapered outer surface of each diaphyseal implant component has a minimum outer dimension at the second end and a maximum outer dimension positioned between the first end and the second end. Each collar component includes a first end having a post and a second end having a tapered bore co-axial with the post of the first end. The tapered bore of the collar component is smaller than the tapered bore of the articulation component. Each collar has a longitudinal axis extending from the first end to the second end. The longitudinal axis extends through the post at the first end and the bore on the second end. Each collar also has a substantially cylindrical portion between the first end and the second end. The substantially cylindrical portion surrounds at least a portion of the bore at the second end and includes an annular surface disposed transverse to the longitudinal axis of the diaphyseal implant component. The tapered post of each collar component is sized and shaped so that the each collar component can be assembled with each articulation component and frictionally locked together by inserting the tapered post of the collar into the tapered bore of the articulation component. The tapered post of each diaphyseal component is sized and shaped so that each diaphyseal component can be assembled with each collar component and frictionally locked together by inserting the tapered post of the diaphyseal component into the tapered bore of the collar component.
[0017] In another aspect, the present invention provides a method of replacing a portion of a long bone having an articulating surface, an intramedullary canal, a diaphysis spaced from the articulating surface, and a periosteum. A plurality of bone replacement components are provided; each bone replacement component is shaped and sized to replace a portion of the long bone, and each bone replacement component includes a tapered bore. A plurality of modular stems are also provided. The stems are to be received in the intramedullary canal of the long bone, and each stem has a free end and an opposite end capable of being connected to another implant component. A plurality of modular diaphyseal implant components are also provided. Each diaphyseal implant component includes a first end with a tapered post and a second end for connection to a selected modular stem. Each diaphyseal implant component also has a longitudinal axis extending between the first end and the second end and a tapered outer surface. The tapered outer surface has a minimum outer dimension at the second end and a maximum outer dimension positioned between the first end and the second end. At least two of the diaphyseal components have different maximum outer diameters. A plurality of collar components is also provided. Each collar component includes a first end having a post and a second end. The second end has a tapered bore co-axial with the post of the first end. The tapered bore of the collar component is smaller than the tapered bore of the bone replacement implant components. Each collar also has a longitudinal axis extending from the first end to the second end. The longitudinal axis extends through the post at the first end and the bore on the second end. A substantially cylindrical porous portion surrounds at least a portion of the bore at the second end. The cylindrical porous portion is between the first end and the second end. At least two of the collar components have different maximum outer diameters. In the method, the bone is resected to remove a portion of the bone and leave at least a portion of the diaphysis of the bone. A tapered bore is prepared in the diaphysis of the bone. One stem component, one diaphyseal component, one collar component and one bone replacement component are selected. An implant assembly is made by connecting the selected stem component to the second end of the selected diaphyseal component, inserting the tapered post of the selected diaphyseal component into the tapered bore of the selected collar component, and inserting the tapered post of the selected collar component into the tapered bore of the selected bone replacement component. The implant assembly is then implanted so that the stem component is received in the intramedullary canal, a substantial part of the diaphyseal component is received in the tapered bore in the diaphysis of the bone and the collar component is exposed outside of the bone.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is an anterior view of a left femur;
[0019] FIG. 2 is a cross-section of a portion of the diaphysis of the femur of FIG. 1 , shown with a stem extension received in the intramedullary canal of the femur;
[0020] FIG. 3 is an elevation of an orthopaedic implant system illustrating the principles of the present invention, including a set of diaphyseal components and a set of collar components;
[0021] FIG. 4 is a longitudinal cross-section of the set of diaphyseal components and collar components of the system of FIG. 3 ;
[0022] FIG. 5 is an end view of one of the diaphyseal components of FIGS. 3-4 ;
[0023] FIG. 6 is a view of the opposite end of the diaphyseal implant component of FIG. 5 ;
[0024] FIG. 7 is an end view of one of the collar components of FIGS. 3-4 ;
[0025] FIG. 8 is a view of the opposite end of the collar component of FIG. 7 ;
[0026] FIG. 9 is an elevation of one possible set of assemblies of diaphyseal components and collar components;
[0027] FIG. 10 is an elevation of another possible set of assemblies of diaphyseal components and collar components;
[0028] FIG. 11 is an exploded perspective view of a distal femoral implant assembly illustrating use of one of the diaphyseal components and collar components of FIGS. 3-4 in use with one style of stem extension;
[0029] FIG. 12 is an exploded perspective view similar to FIG. 11 , but illustrating use of one of the diaphyseal components and collar components of FIGS. 3-4 in use with a different style of stem extension;
[0030] FIG. 13 is a side view of a distal femoral implant assembly including one of the diaphyseal components and collar components of FIGS. 3-4 in use with a different style of stem extension;
[0031] FIG. 14 is an anterior view of the distal femoral implant assembly of FIG. 13 ;
[0032] FIG. 15 is a longitudinal cross-section through a diaphyseal segment of bone and through an assembly of a stem with one of the diaphyseal components, one of the collar components and another implant component;
[0033] FIG. 16 is a cross-section similar to FIG. 15 , but shown with the stem, diaphyseal component and other component assembled with a different collar component from the system;
[0034] FIG. 17 is a side view of a proximal femoral implant assembly including one of the diaphyseal components and collar components of FIGS. 3-4 ;
[0035] FIG. 18 is a perspective view of a proximal tibial implant assembly including one of the diaphyseal components and collar components of FIGS. 3-4 ;
[0036] FIG. 19 is a side view of an intercalary implant assembly including two of the diaphyseal components and two of the collar components of FIGS. 3-4 ;
[0037] FIG. 20 is a side view of an intercalary implant assembly including one of the diaphyseal components and collar components of FIGS. 3-4 ;
[0038] FIG. 21 is a diagrammatic cross-section of a portion of the remaining portion of the diaphysis after a portion of the femur or long bone has been resected;
[0039] FIG. 22 illustrates the remaining resected diaphysis of FIG. 21 after a tapered bore has been prepared at the resection site of the bone; and
[0040] FIG. 23 illustrates the remaining resected diaphysis of FIG. 22 with an implant assembly including a diaphyseal component fully seated in the bone and a collar component outside of the bone.
DETAILED DESCRIPTION
[0041] A modular orthopaedic knee implant system incorporating the principles of the present invention is illustrated in the accompanying drawings. The illustrated modular orthopaedic knee implant system includes components of several existing orthopaedic knee implant systems, along with new components that provide the orthopaedic surgeon with greater flexibility in selecting the appropriate components to suit the needs of an individual patient. These patient needs can include factors such as individual anatomy and the condition of the native bone tissue.
[0042] FIG. 3 illustrates a set 50 of diaphyseal components and a set of collar components 51 that may be used in the system or kit of the present invention. The illustrated set 50 of diaphyseal components includes five sizes of diaphyseal components, labeled 52 A, 52 B, 52 C, 52 D, 52 E. The illustrated set of collar components 51 includes six sizes of collar components, labeled 53 A, 53 B, 53 C, 53 D, 53 E, 53 F.
[0043] The illustrated diaphyseal components 52 A, 52 B, 52 C, 52 D, 52 E include several common features. The illustrated collar components 53 A, 53 B, 53 C, 53 D, 53 E, 53 F also include several common features. In the following description and in the drawings, like parts are identified with the same reference number, followed by a letter designation to identify the particular size of component.
[0044] Each of the illustrated diaphyseal components 52 A, 52 B, 52 C, 52 D, 52 E has a first end 54 A, 54 B, 54 C, 54 D, 54 E, a second end 56 A, 56 B, 56 C, 56 D, 56 E and a longitudinal axis 58 A, 58 B, 58 C, 58 D, 58 E extending from the first end 54 A, 54 B, 54 C, 54 D, 54 E to the second end 56 A, 56 B, 56 C, 56 D, 56 E. Each of the illustrated diaphyseal components 52 A, 52 B, 52 C, 52 D, 52 E also has a tapered outer surface 60 A, 60 B, 60 C, 60 D, 60 E.
[0045] The tapered outer surface 60 A, 60 B, 60 C, 60 D, 60 E of each diaphyseal implant component 52 A, 52 B, 52 C, 52 D, 52 E in the set 50 is of a different size to accommodate the needs of the individual patient's anatomy. The illustrated set includes sizes ranging from extra-extra-small 52 A to large 52 E.
[0046] The tapered outer surface 60 A, 60 B, 60 C, 60 D, 60 E of each diaphyseal implant component 52 A, 52 B, 52 C, 52 D, 52 E in the set 50 has a minimum outer diameter at the second end 56 A, 56 B, 56 C, 56 D, 56 E and a maximum outer diameter spaced from the first end 54 A, 54 B, 54 C, 54 D, 54 E and the second end 56 A, 56 B, 56 C, 56 D, 56 E. The maximum outer diameter is indicated at 66 A, 66 B, 66 C, 66 D, 66 E in FIGS. 3-6 and 9 - 20 .
[0047] The tapered outer surface 60 A, 60 B, 60 C, 60 D, 60 E, 60 F may have a plurality of flats 68 A, 68 B, 68 C, 68 D, 68 E at the maximum outer diameter 66 A, 66 B, 66 C, 66 D, 66 E. The flats may be provided to help to limit rotation of the diaphyseal components 52 A, 52 B, 52 C, 52 D, 52 E with respect to the bone after implantation, as described in more detail below. It should be understood that the diaphyseal implant components could be provided without such flats if desired.
[0048] FIG. 5 illustrates an end view of one of the diaphyseal implant components 52 D of the set 50 , taken from the second end 56 D of the component. FIG. 6 illustrates an end view of the same diaphyseal component 52 D taken from the first end 54 D of the component. As there shown, the tapered outer surface 60 D has four equally spaced flats 68 D connected by curved arcs 70 D. The maximum transverse outer dimensions of the tapered outer surface 60 D are shown at d 1 and d 2 in FIGS. 5-6 ; in the illustrated embodiments, d 1 =d 2 . Thus, the tapered outer surface 60 D has the same maximum transverse outer dimension d 1 , d 2 along two perpendicular axes at the maximum outer dimension 66 D of the tapered outer surface 60 D.
[0049] In the smallest size of diaphyseal implant component 52 A most of the tapered outer surface 60 A has a frustoconical shape, as shown in FIG. 3 . Frusto-conical is intended to mean shaped like the frustum of a cone, that is, it has the shape of the basal part of a solid cone formed by cutting off the top by a plane parallel to the base. The smallest illustrated diaphyseal implant component 52 A also has a first annular step 72 A. In each of the other sizes of diaphyseal implant components 52 B, 52 C, 52 D, 52 E in the set 50 , the tapered outer surface 60 B, 60 C, 60 D, 60 E comprises a plurality of annular steps: there is a first annular step 72 B, 72 C, 72 D, 72 E between the first end 54 B, 54 C, 54 D, 54 E and second end 56 B, 56 C, 56 D, 56 E of the diaphyseal components, a last annular step 74 B, 74 C, 74 D, 74 E at the second end 56 B, 56 C, 56 D, 56 E of the diaphyseal implant component and a plurality of intermediate annular steps 76 B, 76 C, 76 D, 76 E (shown in FIGS. 3 , 9 - 10 and 13 ) between the first step 72 B, 72 C, 72 D, 72 E and last step 74 B, 74 C, 74 D, 74 E.
[0050] Each step has a substantially cylindrically shaped outer surface and a longitudinal height; the largest diameter steps deviate from a cylindrical shape in the illustrated embodiments because of the presence of the four flats 68 .
[0051] In each illustrated size of diaphyseal implant component, the first annular step 72 A, 72 B, 72 C, 72 D, 72 E has the greatest maximum transverse outer dimension, and the maximum transverse outer dimension of each step progressively decreases to the last annular step 74 A, 74 B, 74 C, 74 D, 74 E which has the smallest maximum transverse outer dimension. In the illustrated set of diaphyseal implant components 52 A, 52 B, 52 C, 52 D, 52 E examples of sizes and numbers of steps are provided in the following table:
Extra Extra Small Diaphyseal Implant Component 52A Outer Height Diameter Taper Angle First step 72A 2 mm 12.95 mm — Frustoconical 15.04 mm 12.65 mm 3° Portion 71A maximum to 10.67 mm minimum Last Step 74A 2 mm 9.81 mm Step Step Outer Overall Height Diameter Taper Angle Extra Small Diaphyseal Implant Component 52B First step 72B 2 mm 15.23 mm 4°52′ Second step 4 mm 14.37 mm Third step 4 mm 13.51 mm Fourth step 4 mm 12.65 mm Last step 74B 4 mm 11.79 mm Small Diaphyseal Implant Component 52C First step 72C 2 mm 19.09 mm 4°33′ Second step 4 mm 18.37 mm Third step 4 mm 17.65 mm Fourth step 4 mm 16.93 mm Fifth step 4 mm 16.21 mm Last step 74C 4 mm 15.49 mm Medium Diaphyseal Implant Component 52D First step 72D 2 mm 22.53 mm 6°35′ Second step 4 mm 21.51 mm Third step 4 mm 20.49 mm Fourth step 4 mm 19.47 mm Fifth step 4 mm 18.45 mm Sixth step 4 mm 17.43 mm Last step 74D 4 mm 16.41 mm Large Diaphyseal Implant Component 52E First step 72E 2 mm 26.51 mm 6°39′ Second step 4 mm 25.49 mm Third step 4 mm 24.47 mm Fourth step 4 mm 23.45 mm Fifth step 4 mm 22.44 mm Sixth step 4 mm 21.42 mm Seventh step 4 mm 20.40 mm Last step 74E 4 mm 19.38 mm
[0052] In the above table, the Overall Taper Angle refers to the angle defined by a line tangent to the steps 72 , 74 , 76 and a line parallel to the longitudinal axis 58 in each size.
[0053] It should be understood that the sizes, numbers of steps and overall taper angles identified in the above tables are provided as examples only. The present invention is not limited to a stepped configuration or to any particular size, number of steps or overall angle of taper unless expressly called for in the claims. Moreover, although five sizes are illustrated in the set 50 , fewer or more sizes could be provided; the invention is not limited to any number of sizes of implant components in a set unless expressly called for in the claims.
[0054] In each of the illustrated diaphyseal implant components 52 A, 52 B, 52 C, 52 D, 52 E, most of the tapered outer surface is porous: the frusto-conical portion of the small implant component 52 A and its first step 72 A are porous and all of the first and intermediate steps 72 B, 72 C, 72 D, 72 E, 76 B, 76 C, 76 D, 76 E of the other sizes of diaphyseal implant components 52 B, 52 C, 52 D, 52 E are porous. The last or smallest diameter step 74 in each size is not porous in the illustrated embodiment.
[0055] As used herein, “porous” refers to a surface that is conducive to bone ingrowth for non-cemented fixation, and “smooth” refers to a surface that is not conducive to such bone ingrowth. Suitable porous surfaces can be made by many different methods: casting, embossing, etching, milling, machining, and coating such as by plasma-spraying or by bonding, for example. Bonded materials can comprise sintered metal beads, sintered metal mesh or screen, or sintered metal fibers, for example. Known, commercially available materials and techniques can be used to create the porous outer surfaces of the diaphyseal components and collar components: for example, POROCOAT® coating, used by DePuy Orthopaedics, Inc. of Warsaw, Ind., could be used, as well as other commercially available coatings. In addition, the porous surfaces may include other materials conducive to bone ingrowth, such as hydroxy apatite coatings, for example. It should be understood that the above-identified examples of materials, methods and commercial products are provided as examples only; the present invention is not limited to any particular material, method or commercial product for the porous surfaces unless expressly called for in the claims. In addition, it should be understood that as additional materials and methods become available to create surfaces that promote bony ingrowth, it is believed that such other materials and methods may also be useful with the present invention.
[0056] Each of the flats 68 A, 68 B, 68 C, 68 D, 68 E in the illustrated diaphyseal components 52 A, 52 B, 52 C, 52 D, 52 E is 6 mm high. The flats are disposed at 90° intervals around the first step and second step in the diaphyseal implant components 52 B, 52 C, 52 D, 52 E that have stepped tapered outer surfaces 60 B, 60 C, 60 D, 60 E and are also disposed at 90° intervals around the tapered frustoconical surface 71 A and first step 72 A of the smallest diaphyseal implant component 52 A. It should be understood that the flats may have different dimensions and different positions.
[0057] As illustrated in FIGS. 3-4 , each diaphyseal component 52 A, 52 B, 52 C, 52 D, 52 E also includes a Morse taper post 73 A, 73 B, 73 C, 73 D, 73 E at the first end 54 A, 54 B, 54 C, 54 D, 54 E of the component. In the set of diaphyseal components, although the sizes of the tapered outer surfaces 60 A, 60 B, 60 C, 60 D, 60 E vary, the Morse taper posts 73 A, 73 B, 73 C, 73 D, 73 E of all of the diaphyseal components 52 A, 52 B, 52 C, 52 D, 52 E are of the same size and shape. The Morse taper posts of the illustrated diaphyseal components are frusto-conical, with diameters of 12.87 mm (0.5069 inches) at the narrowest point, lengths of 15.25 mm (0.600 inches) and taper angles of 2°50′0″. It should be understood that these and all dimensions provided in this description are provided for illustrative purposes only; the invention is not limited to these dimensions or any other dimension unless expressly called for in one of the claims.
[0058] As shown in FIG. 4 , the Morse taper posts 73 A, 73 B, 73 C, 73 D, 73 E all have longitudinal channels 75 A, 75 B, 75 C, 75 D, 75 E aligned along their central longitudinal axes 58 A, 58 B, 58 C, 58 D, 58 E that communicate with bores 77 A, 77 B, 77 C, 77 D, 77 E at the second ends 56 A, 56 B, 56 C, 56 D, 56 E of the diaphyseal components 52 A, 52 B, 52 C, 52 D, 52 E. As described in more detail below, the bores 77 A, 77 B, 77 C, 77 D, 77 E are provided for connecting stem members to the second ends of the diaphyseal components.
[0059] The Morse taper posts 73 A, 73 B 79 , 73 C, 73 D, 73 E are sized and shaped to mate and frictionally lock with Morse taper bores A, 79 B, 79 C, 79 D, 79 E, 79 F formed in the collar components 53 A, 53 B, 53 C, 53 D, 53 E, 53 F. All of the Morse taper bores 79 A, 79 B, 79 C, 79 D, 79 E, 79 F have the same size and shape. Accordingly, each collar component 53 A, 53 B, 53 C, 53 D, 53 E, 53 F is capable of being assembled with each diaphyseal component 52 A, 52 B, 52 C, 52 D, 52 E. The Morse taper bores 79 A, 79 B, 79 C, 79 D, 79 E, 79 F of the illustrated collar components 53 A, 53 B, 53 C, 53 D, 53 E, 53 F are frusto-conical, with diameters of 13.87 mm (0.546 inches) at the widest points (shown at d 5 in FIG. 7 ), depths of 17.35 mm (0.683 inches), and taper angles of 2°50′0″. It should be understood that these and all dimensions provided in this description are provided for illustrative purposes only; the invention is not limited to these dimensions or any other dimension unless expressly called for in one of the claims.
[0060] The Morse taper bores 79 A, 79 B, 79 C, 79 D, 79 E, 79 F of the collar components 53 A, 53 B, 53 C, 53 D, 53 E, 53 F are centered on the central longitudinal axes 81 A, 81 B, 81 C, 81 D, 81 E, 81 F of the collar components and in communication with longitudinal channels 83 A, 83 B, 83 C, 83 D, 83 E, 83 F that extend through Morse taper posts 85 A, 85 B, 85 C, 85 D, 85 E, 85 F. The Morse taper posts 85 A, 85 B, 85 C, 85 D, 85 E, 85 F of the collar components are at a first end 87 A, 87 B, 87 C, 87 D, 87 E, 87 F of the collar components and the Morse taper bores 79 A, 79 B, 79 C, 79 D, 79 E, 79 F of the collar components are at a second end 89 A, 89 B, 89 C, 89 D, 89 E, 89 F of the collar components.
[0061] The Morse taper posts 85 A, 85 B, 85 C, 85 D, 85 E, 85 F of the collar components 53 A, 53 B, 53 C, 53 D, 53 E, 53 F are sized and shaped to be received within and frictionally lock with the Morse taper bores of the bone replacement components, that is, the articulation components and the intercalary components. Accordingly, the Morse taper posts 85 A, 85 B, 85 C, 85 D, 85 E, 85 F may each have a length of 20.32 mm (0.800 inches) to be received in Morse taper bores in the articulation components and intercalary components having a depth of about 24.13 mm (0.950 inches). Maximum outer diameters (shown at d 5 in FIG. 8 ) for the Morse taper posts of the collar components may be, for example, 19.01 mm (0.7485 inches), to be received in bores having maximum diameters of, for example, 19.05 mm (0.7500 inches). For all of the Morse tapers in the system, any typical angle for Morse tapers may be used, such as 2°24′35″, for example. It should be understood that dimensions and angles are provided herein by way of example only; the present invention is not limited to any particular dimension or angle unless expressly called for in the claims.
[0062] In each of the illustrated sizes of collar components 53 A, 53 B, 53 C, 53 D, 53 E, 53 F, at least a portion of the outer surface of each collar is cylindrical in shape. As shown in FIG. 3 , in the extra extra small component 52 A and extra small component 52 B, all or substantially all of the outer surface of the collar 39 A is cylindrical in shape; in the other larger sizes 52 C, 52 D, 52 E the collars 53 C, 53 D, 53 E, 53 F include a cylindrical portion 82 C, 82 D, 82 E, 82 F at the second end 89 C, 89 D, 89 E, 89 F and a frusto-conical portion 84 C, 84 D, 84 E, 84 F at the first end 87 C, 87 D, 87 E, 87 F. A portion or all of each collar component may be porous; for example, an annular porous strip having a height (longitudinal dimension) of 10 mm may be provided on the cylindrical portions 82 A, 82 B, 82 C, 82 D, 82 E, 82 F for tissue attachment and ingrowth. Variations in the type and characteristics of the porous coating may be made to encourage soft tissue ingrowth, as opposed to bone ingrowth. Moreover, features may be included on the collar to allow for attachment of soft tissue or the periosteum to the collar; for example, suture holes may be provided. Preferably, a portion of each collar component has a surface that is conducive to ingrowth of the periosteum.
[0063] Each collar component 53 A, 53 B, 53 C, 53 D, 53 E, 53 F includes a transverse annular surface 86 A, 86 B, 86 C, 86 D, 86 E, 86 F that is perpendicular to the longitudinal axis 81 A, 81 B, 81 C, 81 D, 81 E, 81 F of the collar component. The transverse annular surfaces 86 A, 86 B, 86 C, 86 D, 86 E, 86 F surround the openings into the Morse taper bores 79 A, 79 B, 79 C, 79 D, 79 E, 79 F and have different diameters (shown for example at d 4 in FIG. 7 ). Examples of possible longitudinal lengths of the collar components apart from the Morse taper posts (shown at 1 in FIG. 3 at component 53 F) as well as possible dimensions for d 4 are provided in the following table:
Dimension Component d 4 L 53A 15 mm 20 mm 53B 19 mm 20 mm 53C 23 mm 20 mm 53D 27 mm 20 mm 53E 31 mm 20 mm 53F 35 mm 20 mm
[0064] With a porous coating, the dimension d 4 should increase by about 1.5 mm (sixty-thousandths of an inch). It should be understood that these dimensions are provided as examples only; the present invention is not limited to any particular dimension unless expressly called for in the claims. The transverse annular surface 86 A, 86 B, 86 C, 86 D, 86 E, 86 F may be porous or smooth over all or a portion of its surface area. If porous, the transverse annular surface may provide a surface conducive to tissue ingrowth. It may be desirable to limit any porous coating to the outer portions of the transverse annular surface.
[0065] FIGS. 9 and 10 illustrate various assemblies of diaphyseal components 52 A, 52 B, 52 C, 52 D, 52 E, 52 F and collar components 53 A, 53 B, 53 C, 53 D, 53 D, 53 E, 53 F. In the assemblies illustrated in FIG. 9 , the diaphyseal components and collar components are selected so that a substantial portion of the annular surfaces 86 B, 86 C, 86 D, 86 E, 86 F are exposed beyond the first step 72 A, 72 B, 72 C, 72 D, 72 E of the diaphyseal implant component. In the assemblies illustrated in FIG. 10 , the diaphyseal components and collar components are selected so that the outer diameters of the transverse annular surfaces 86 A, 86 B, 86 C, 86 D of the collar components substantially match the maximum transverse dimensions of the diaphyseal components.
[0066] FIGS. 15 and 16 illustrate the results of using assemblies of the types shown in FIGS. 9 and 10 . In FIG. 15 , the annular surface 86 E of the collar component 53 E is large enough so that the resected end of the bone 91 may bear against the outer rim of the annular surface 86 E if the diaphyseal component 52 E should subside in the bone. In FIG. 16 , the annular surface 86 D of the collar component has a smaller diameter and is substantially covered by the diaphyseal component. Depending on surgeon preference and the individual needs of the patient, with the modular system of the present invention the surgeon may opt to have the annular surface of the collar component partially exposed or substantially covered.
[0067] FIGS. 11-12 illustrate the large size diaphyseal implant component 52 E and largest size of collar component 53 F in exploded views with other modular implant components that may be included in a kit or system and assembled with the diaphyseal implant component 52 E and collar component 53 F for implantation. In FIGS. 11-12 , the assembly is intended for use in replacing a portion of the distal femur. The assemblies of both FIGS. 11 and 12 include a distal femoral implant 100 , a segmental implant component 102 , a collar component 53 F, a diaphyseal component 52 E, and a stem extension. The assembly of FIG. 12 also includes an adapter component 116 . Features of the adapter 116 are disclosed in more detail in U.S. patent application Ser. No. 10/817,051 entitled “Modular Implant System with Fully Porous Coated Sleeve”, filed on Apr. 2, 2004 by Goodfried, Hazebrouck, Lester and Brown, the complete disclosure of which is incorporated by reference herein.
[0068] In FIG. 11 , the stem extension 104 has a coronal-slotted free end or tip 106 , a body 107 and a connection end 108 . The connection end 108 comprises a Morse taper post in the embodiment of FIG. 8 . The Morse taper post at the connection end 108 is received within and frictionally locks with the Morse taper bore 77 E of the diaphyseal component 52 E. In FIG. 12 , the stem extension 110 has a free end or tip 112 , a body 113 and a connection end 114 that comprises a male threaded member. The embodiment of FIG. 12 also includes an adapter 116 with a threaded opening (not shown) to receive the male threaded connection end 114 of the stem extension and a Morse taper post 118 to be received in the Morse taper bore 77 E of the diaphyseal implant component 52 E. All of the large size diaphyseal implant components 52 C, 52 D, 52 E can be assembled with stem extensions in the manners illustrated in FIGS. 11-12 . Due to constraints on the thicknesses of the walls of the tapered outer surfaces 60 A, 60 B of the smaller sized diaphyseal implant components 52 A, 52 B, accommodation is only made for connection to a stem extension with a threaded male end of the type shown in FIG. 12 .
[0069] The bodies 107 , 113 of the stem extensions 104 , 110 may vary. For example, a substantial part of the length of the body, such as body 107 of FIG. 11 , can be porous. Alternatively, the body can be sized and shaped for cemented application, like the body 113 of the stem extension 110 of FIG. 12 . Alternatively, the body of the stem extension can be splined.
[0070] FIGS. 13-14 illustrate a stem extension 115 with a coronal slotted free end 117 , a splined body 119 , and a connection end (not shown) comprising a Morse taper post. In the embodiment of FIGS. 13-14 , the splined body 119 of the stem extension 115 comprises a plurality of cutting flutes. The stem extension 115 of FIGS. 13-14 is not porous. Although in FIGS. 13-14 the free end 117 of the stem extension 115 is illustrated as being substantially flat, it may be desirable for the free end 117 to be bullet-shaped.
[0071] For the femoral articulation components 100 and segmental components 102 of FIGS. 11-14 , U.S. Pat. Publication No. US2003/0204267A1, which is incorporated by reference herein in its entirety, discloses additional details regarding the Morse taper bores in the femoral and segmental components, and of appropriate Morse taper posts for use with such components.
[0072] As disclosed in U.S. Pat. Publication No. US2003/0204267A1, the distal femoral implant component 100 and segmental component 102 both include tabs 120 . Each of the collar components 53 A, 53 B, 53 C, 53 D, 53 E, 53 F include corresponding notches 122 to receive the tabs 120 to prevent the collar components from rotating. These notches can also be used to separate the components if necessary; a tool such as that disclosed in U.S. Pat. No. 6,786,931 may be used.
[0073] It should be understood that a typical implant kit or system would include several sizes of distal femoral implant components 100 , segmental components 102 and stem extensions 104 , 110 . It should also be understood that depending on the size and shape of the distal femoral component, it may not be necessary to use a segmental component 102 ; the collar components 53 A, 53 B, 53 C, 53 D, 53 E, 53 F could be connected directly to the femoral implant component 100 .
[0074] Use of the diaphyseal components 52 A, 52 B, 52 C, 52 D, 52 E and collar components 53 A, 53 B, 53 C, 53 D, 53 E, 53 F of the present invention is not limited to segmental components and femoral components. As illustrated in FIGS. 17-20 , the diaphyseal components and collar components of the present invention can be used with other implant components having an articulation portion. For example, as shown in FIG. 17 , the articulation portion of the implant component could comprise a proximal femoral component 150 (including a femoral head 152 ). As shown in FIG. 18 the articulation portion of the implant component could comprise a proximal tibia component 154 or other component, such as a proximal humeral component (not shown).
[0075] As shown in FIGS. 19-20 , the implant component could be an intercalary implant instead of an articulation component. FIG. 19 illustrates two large size diaphyseal implant components 52 E and two large size collar components 53 F in use with a two-piece intercalary implant 156 of the type disclosed in U.S. Publication No. US2004/0193268A1 entitled “Intercalary Prosthesis, Kit and Method,” filed Mar. 31, 2003 by Hazebrouck, incorporated by reference herein in its entirety, or those disclosed in U.S. Publication No. US2004/0193267A1 entitled “Intercalary Implant,” filed on Mar. 31, 2003 by Natalie Heck and Michael C. Jones (also incorporated by reference herein in its entirety). Such implants may be used with intercalary trials such as those disclosed in U.S. Publication No. US2005/0107794A1, entitled “Orthopaedic Spacer,” filed on Sep. 24, 2004 by Hazebrouck, the complete disclosure of which is incorporated by reference herein. FIG. 20 illustrates a single diaphyseal component 52 E and collar component 53 F in use with the two-piece intercalary component 156 and a standard stem extension 157 for the LPS implant system.
[0076] In FIGS. 17-20 the stem extension is shown diagrammatically and indicated generally by reference number 121 , with the free end indicated by reference number 123 . Other than the bullet shape of the free end 123 , no other features are shown for the body 125 of the stem extension. It should be understood that the body 125 of the stem extension 121 in any of FIGS. 17-20 could have any of the above described features, such as splined cutting flutes, a porous coating, a coronally slotted free end, or could be designed for cemented application.
[0077] All of the components of the illustrated implant systems can be made of standard materials for such implants, such as titanium and cobalt-chrome alloys.
[0078] It should be understood that although the principles of the present invention are described and illustrated with reference to implant components available from DePuy Orthopaedics, Inc., the invention is not limited to these components or their features. The principles of the present invention can be applied to other implant components, including those of other manufacturers and those subsequently developed.
[0079] In use, depending on the condition of the native bone tissue, the orthopaedic surgeon will determine the amount of bone to be resected from the femur (or other long bone). Commercially available instrumentation can be used to resect the bone in the appropriate manner. The diaphysis of a resected bone is illustrated in FIGS. 21-23 at 200 . If it is desirable to use a diaphyseal implant component 52 A, 52 B, 52 C, 52 D, 52 E to secure the implant in place, the surgeon can then select an appropriate size of diaphyseal implant component 52 A, 52 B, 52 C, 52 D or 52 E for the individual patient. The diaphysis 200 of the bone can then be prepared to receive the selected diaphyseal implant component 52 A, 52 B, 52 C, 52 D or 52 E. The surgeon can use a conical reamer (not shown) of a size and shape matching the size and shape of the selected diaphyseal component to mill or machine the diaphysis 200 of the bone to create a tapered bore that closely matches the size and shape of the tapered outer surface 60 A, 60 B, 60 C, 60 D, 60 E of the selected diaphyseal implant component. A tapered bore is illustrated in FIGS. 22-23 at 202 . Since the tapered bore is created to match the size and shape of the selected diaphyseal component, the implants and techniques of the present invention are adaptable to different patient anatomies.
[0080] The surgeon may select an appropriate size collar component according to the surgeon's preferences and the needs of the patient. If the surgeon decides that the optimum patient outcome would result from the use of an assembly that provides a transverse surface to bear against the resected bone, the surgeon would select a collar component wherein the diameter of the transverse annular surface 86 is greater than the maximum transverse outer dimension of the diaphyseal component. It the surgeon decides that the optimum patient outcome would result from use of an assembly that does not provide a transverse surface to bear against the resected bone, the surgeon would select a collar component wherein the diameter of the transverse annular surface 86 does not exceed the maximum transverse outer dimension of the diaphyseal component. Once the appropriate diaphyseal and collar components are selected, the two components may be frictionally locked together by pushing the Morse taper post 73 A, 73 B, 73 C, 73 D, 73 E of the diaphyseal component into the mating Morse taper bore 79 B, 79 C, 79 D, 79 E, 79 F of the collar component 53 A, 53 B, 53 C, 53 D, 53 E, 53 F.
[0081] The surgeon may select a stem extension appropriate to the individual patient and assemble the stem extension with the subassembly of the diaphyseal component and the collar component. The surgeon would also assemble the intercalary component or articulation component with the other parts by inserting the Morse taper post of the collar component into the mating Morse taper bore of the intercalary or articulation component. The stem extension and part of the diaphyseal implant component of the assembled implant, can then be inserted into the bone as illustrated in FIG. 23 and positioned with the tip or free end of the stem extension engaging the bone surface of the intramedullary canal 204 and with the tapered outer surface 60 A, 60 B, 60 C, 60 D or 60 E bearing against the tapered diaphyseal bone defining the tapered bore 202 . The stem extension in FIG. 21 is identified with reference number 121 and its free end is identified with reference number 123 ; as discussed above with respect to FIGS. 17-20 , the stem extension 121 is illustrated diagrammatically, and can include any of the features of the stem extensions 104 , 110 , 115 described above. Because of the shapes and textures of the implant components 121 , 52 A, 52 B, 52 C, 52 D or 52 E received within the bone, there should be no binding before the diaphyseal component 52 A, 52 B, 52 C, 52 D or 52 E is fully seated. Accordingly, implantation should be relatively easy.
[0082] It should be understood that the present invention is not limited to any particular order of assembly of the components. For example, the collar component and articulation component could be assembled and then assembled with the diaphyseal component, or the collar component and diaphyseal component can be assembled and then assembled with the articulation component.
[0083] Generally, when implanted, the first step 72 A, 72 B, 72 C, 72 D, 72 E of each of the diaphyseal implant components 52 A, 52 B, 52 C, 52 D, 52 E and the outer surface of the collar component (other than the Morse taper post) will be exposed outside of the bone as shown in FIG. 23 . Subsequently, some subsidence of the implant can occur over time without damage to the bone. The flats 68 E prevent the diaphyseal component 52 E from rotating or turning in the tapered bore 202 that the surgeon created for it.
[0084] As shown in FIG. 23 , when fully seated, the implant assembly contacts the bone at both the tip 123 of the stem extension 121 and at the tapered outer surface 60 E of the diaphyseal component 52 E. Bone ingrowth can occur around the entire tapered outer surface 60 E of the diaphyseal implant component 52 E. Depending on the intramedullary canal anatomy and characteristics of the stem extension, bone ingrowth can also occur along all or part of the body of the stem; for example, bone ingrowth could occur at the free end of the stem extension and/or at any area between the diaphyseal component and the free end of the stem. For example, if a cemented stem extension is used, such as the stem extension 110 of FIG. 12 , there should be no bone ingrowth along the body of the stem. Similarly, no substantial bone ingrowth should occur along the stem with the splined stem extension 115 of FIGS. 13-14 . If all or part of the stem extension 104 of FIG. 11 is porous, bone ingrowth can be expected at the porous area.
[0085] With the stepped designs of the larger diaphyseal implant components, such as diaphyseal implant components 52 B, 52 C, 52 D, 52 E, shear forces are essentially converted to compressive loads, and the compressive loads are spread among the steps 74 , 76 contacting the diaphyseal bone defining the tapered bore 202 . Accordingly, the implant is immediately stable and capable of bearing weight. In addition, with the bone bearing the axial load at the tapered bore 202 , there is no disadvantageous stress shielding of the bone. Moreover, with the implant assembly contacting the bone at both the tip 106 of the stem extension and at the contacting surfaces of the diaphyseal bone defining the tapered bore 202 and tapered outer surface 60 , any moment arm is significantly reduced if not eliminated. With bone ingrowth occurring at both spaced locations over time, long term implant stability should be improved. Accordingly, the implant assembly of the present invention should be less likely to loosen over time.
[0086] As can be seen in FIGS. 15 and 23 , a small gap 220 may be between the exposed resected bone surface and the transverse annular surface 86 E of the collar 53 E when implanted. If the implant does subside, this gap can decrease to the point that the transverse annular surface 86 E bears directly against the exposed resected bone surface. If the transverse annular surface is porous, tissue ingrowth can occur in the gap 220 over time to seal the intramedullary canal 204 against debris.
[0087] With any of the illustrated assemblies, the periosteum of the bone should grow into the porous outer surface of the collar component 53 . Essentially the ingrowth of tissue along the cylindrical outer surface of the collar (or along the exposed portion of the transverse annular surface of the collar) should effectively seal off the intramedullary canal, to thereby protect the patient from injury or disease resulting from debris entering into the intramedullary canal.
[0088] With the modular implant system of the present invention, it should be possible to reduce inventory of the necessary parts in an implant system or kit.
[0089] It should also be understood that a typical surgical kit would also include trial implant components like those shown in FIGS. 3-4 and 8 - 15 . The surgeon would typically assemble a trial implant and temporarily secure the trial implant assembly in place on the prepared diaphyseal bone to ensure that the assembled implant will be the optimum for the individual patient's needs. The trial components can have features like those described above for the final implant components.
[0090] In case it is necessary to ultimately remove the implant assembly from the patient, such removal should not require the removal of excessive bone stock, since it should only be necessary to remove the portion of the diaphysis defining the tapered bore 202 .
[0091] Various modifications and additions can be made to the above-described embodiments without departing from spirit of the invention. All such modifications and additions are intended to fall within the scope of the claims unless the claims expressly call for a specific construction. | A modular implant system includes a set of anatomically-designed diaphyseal fitting and filling modular implant components and collars. The diaphyseal component connects with a selected intramedullary stem and with a selected collar component. The collar component connects to another implant component such as a modular articular component, a segmental component or an intercalary component. The diaphyseal component has a tapered porous surface that is received with a tapered bore in the bone diaphysis that is prepared to match the size and shape of the tapered porous surface. The collar component has a porous surface for tissue ingrowth, such as the periosteum, to seal the intramedullary canal. The diaphyseal implant is easy to insert and remove, does not bind before fully seating to prevent stress shielding, and eliminates the long lever arm created when fixation occurs only at the tip of the stem, and should eliminate related stem loosening. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application 61/040,562, filed Mar. 28, 2008, which is hereby incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was made with United States government support awarded by the following agencies: National Science Foundation Grant CHE-0449959. The United States government has certain rights in the invention.
BACKGROUND OF INVENTION
[0003] The emergence of resistant bacterial strains without the increased development of new antibiotic structure classes constitutes a serious medical crisis. Brown, E. D.; Wright, G. D. Chem. Rev. 2005, 105, 759-774; Coates, A.; Hu, Y.; Bax, R.; Page, C. Nat. Rev. Drug Discovery 2002, 1, 895-910. Infection with the common pathogen Staphylococcus aureus has been estimated to double the cost, length of stay, and the even death rate in New York City hospitals. Rubin, R. J.; Harrington, C. A.; Poon, A.; Dietrich, K.; Greene, J. A.; Moiduddin, A. Emerging Infectious Diseases 1999, 5, 9-17. Designing antibiotics that treat bacterial infections is a constant struggle for synthetic chemists and biologists because bacteria have an extraordinary ability to adapt and develop resistance to new antibacterial agents. For example, the most recent antibiotic, Linezolid, was released on the market in 2000, only to have cases of Linezolid-resistant bacteria reported the following year. This was alarming news, because Linezolid is a member of the oxazolidinone family, a structure class that had never previously been used as a scaffold for antibacterial agents. This development underscores the need for the discovery of new structural scaffolds with antibacterial activity.
[0004] Combinatorial chemistry continues to play an important role in advancing the chemical biology and drug discovery fields. Navre, M., Application of combinatorial chemistry to antimicrobial drug discovery. Expert Opin. Invest. Drugs 1998, 7, 1257-1269; Seneci, P.; Miertus, S., Combinatorial chemistry and high-throughput screening in drug discovery: Different strategies and formats. Mol. Diversity. 2000, 5, 75-89. One of the main advantages of combinatorial chemistry is the ability to generate a large, diverse library of compounds using a minimum amount of reagents in a relatively short amount of time. Because a combinatorial approach can generate a large number of compounds, this makes it ideal for probing and studying biological targets.
[0005] Solid-phase chemistry has taken on a major role in advancing combinatorial chemistry. Ganesan, A., Recent developments in combinatorial organic synthesis. Drug Discovery Today 2002, 7, 47-55; Balasubramanian, S., Solid phase chemical technologies for combinatorial chemistry. J. Cell. Biochem. 2001, 28-33; Bannwarth, W., Solid phase chemistry. Linkers for solid-phase organic synthesis (SPOS) and combinatorial approaches on solid support. Methods Princ. Med. Chem. 2000, 9, 47-98. Traditional solid phase techniques employ hydrophobic polymeric supports, such as polystyrene beads. Yu, Z. R.; Bradley, M., Solid supports for combinatorial chemistry. Curr. Opin. Chem. Biol. 2002, 6, 347-352. Although these solid supports offer advantages, including rapid and easy compound purification, there are some disadvantages. The hydrophobic nature of polystyrene beads is not compatible with many reactions that require the use of aqueous or certain polar solvents. Recently, the implementation of small molecule macroarrays in combinatorial chemistry has lead to an improved ability to perform both on- and off-support biological assays. Blackwell, H. E., Hitting the SPOT: small-molecule macroarrays advance combinatorial synthesis. Curr. Opin. Chem. Biol. 2006, 10, 203-212; Bowman, M. D.; Jacobson, M. M.; Blackwell, H. E., Discovery of fluorescent cyanopyridine and deazalumazine dyes using small molecule macroarrays. Org. Lett. 2006, 8, 1645-1648; Bowman, M. D.; Jacobson, M. M.; Pujanauski, B. G.; Blackwell, H. E., Efficient synthesis of small molecule macroarrays: optimization of the macroarray synthesis platform and examination of microwave and conventional heating methods. Tetrahedron 2006, 62, 4715-4727; Lin, Q.; Blackwell, H. E., Rapid synthesis of diketopiperazine macroarrays via Ugi four-component reactions on planar solid supports. Chem. Commun. 2006, 2884-2886.
[0006] Solid phase synthesis requires a linker to attach or “link” a synthesized substrate to an insoluble support. A variety of linkers have been used in solid phase synthesis, with two of the most widely used being the Wang and Rink linkers. James, I. W., Linkers for solid phase organic synthesis. Tetrahedron 1999, 55, 4855-4946. These two acid labile linkers are advantageous for synthesis because they can be cleaved with relatively mild acids in a short period of time.
[0007] Small molecule macroarrays can be traced back to the origins of the SPOT-synthesis technique. Frank, R., Spot-Synthesis—an Easy Technique for the Positionally Addressable, Parallel Chemical Synthesis on a Membrane Support. Tetrahedron 1992, 48, 9217-9232. Frank originally designed the SPOT-synthesis technique for the construction of peptide libraries as an alternative to standard solid phase peptide synthesis approaches (i.e. the use of polystyrene beads). Using the SPOT technique individual polypeptides can be synthesized in a spatially addressed format, and the resulting polypeptide arrays can be used in a variety of on support biological assays.
[0008] The generation of small molecule macroarrays involves the use of a planar cellulose support for library construction. This cellulose support is readily accessible laboratory filter paper, an inexpensive alternative to other solid-phase supports. A variety of organic compounds can be used as building blocks for constructing arrays of small molecules. Recently, Blackwell et al. has constructed small molecule macroarrays utilizing multi-component reactions, and microwave irradiation to construct libraries of heterocylces, chalcones, diketopiperazines, and fluorescent cyanopyridine and deazalumazine dyes. Bowman, M. D.; Jeske, R. C.; Blackwell, H. E., Microwave-accelerated SPOT-synthesis on cellulose supports. Org. Lett. 2004, 6, 2019-2022; Lin, Q.; O'Neill, J. C.; Blackwell, H. E., Small molecule macroarray construction via Ugi four-component reactions. Org. Lett. 2005, 7, 4455-4458; Bowman, M. D.; Jacobson, M. M.; Blackwell, H. E., Discovery of fluorescent cyanopyridine and deazalumazine dyes using small molecule macroarrays. Org. Lett. 2006, 8, 1645-1648; Bowman, M. D.; Jacobson, M. M.; Pujanauski, B. G.; Blackwell, H. E., Efficient synthesis of small molecule macroarrays: optimization of the macroarray synthesis platform and examination of microwave and conventional heating methods. Tetrahedron 2006, 62, 4715-4727. Small molecule macroarrays have advantages over traditional solution-phase synthesis, as several hundred compounds can be synthesized in high purity and screened for biological activity in a few days using a minimal amount of reagents, for example as illustrated in FIG. 1 .
[0009] Application of a combinatorial approach to the identification of antibacterial agents permits the generation of diverse arrays of compounds that can be screened for antibacterial activity. Several new antibacterial agents have been identified in combinatorial libraries using a variety of screening techniques, including pyrrolidine bis-cyclic guanidines, hydrazinyl urea-based compounds, benzopyrans, thymidinyl derivatives, and natural product derivatives, and certain 1,3-diphenyl-2-propen-1-ones (chalcones). Hensler, M. E.; Bernstein, G.; Nizet, V.; Nefzi, A., Pyrrolidine bis-cyclic guanidines with antimicrobial activity against drug-resistant Gram-positive pathogens identified from a mixture-based combinatorial library. Bioorg. Med. Chem. Lett. 2006, 16, 5073-5079; Nicolaou, K. C.; Roecker, A. J.; Barluenga, S.; Pfefferkorn, J. A.; Cao, G. Q., Discovery of novel antibacterial agents active against methicillin-resistant Staphylococcus aureus from combinatorial benzopyran libraries. Chembiochem 2001, 2, 460-465; Sun, D.; Lee, R. E., Solid-phase synthesis development of a thymidinyl and 2′-deoxyuridinyl Ugi library for anti-bacterial agent screening. Tetrahedron Lett. 2005, 46, 8497-8501; Shi, S.; Zhu, S.; Gerritz, S. W.; Esposito, K.; Padmanabha, R.; Li, W.; Herbst, J. J.; Wong, H.; Shu, Y. Z.; Lam, K. S.; Sofia, M. J., Solid-phase synthesis and anti-infective activity of a combinatorial library based on the natural product anisomycin. Bioorg. Med. Chem. Lett. 2005, 15, 4151-4154; Ansari, F. L.; Nazir, S.; Noureen, H.; Mirza, B., Combinatorial synthesis and antibacterial evaluation of an indexed chalcone library. Chem. Biodiv. 2005, 2, 1656-1664.
[0010] Chalcones are small molecule natural products found in a variety of plants that exhibit a wide range of biological activities. Kromann, H.; Larsen, M.; Boesen, T.; Schonning, K.; Nielsen, S. F., Synthesis of prenylated benzaldehydes and their use in the synthesis of analogues of licochalcone A. Eur. J. Med. Chem. 2004, 39, 993-1000; Jun, N.; Hong, G.; Jun, K., Synthesis and evaluation of 2′,4′,6′-trihydroxychalcones as a new class of tyrosinase inhibitors. Bioorg. Med. Chem. 2007, 15, 2396-2402; Lawrence, N. J.; Patterson, R. P.; Ooi, L.-L.; Cook, D.; Ducki, S., Effects of a-substitutions on structure and biological activity of anticancer chalcones. Bioorg. Med. Chem. Lett. 2006, 16, 5844-5848; Modzelewska, A.; Pettit, C.; Achanta, G.; Davidson, N. E.; Huang, P.; Khan, S. R., Anticancer activities of novel chalcone and bis-chalcone derivatives. Bioorg. Med. Chem. 2006, 14, 3491-3495.
[0011] Certain chalcones exhibit antimicrobial activity. Sivakumar, P. M.; Seenivasan, S. P.; Kumar, V.; Doble, M., Synthesis, antimycobacterial activity evaluation, and QSAR studies of chalcone derivatives. Bioorg. Med. Chem. Lett. 2007, 17, 1695-1700; Gafner, S.; Wolfender, J.-L.; Mavi, S.; Hostettmann, K., Antifungal and antibacterial chalcones from Myrica serrata. Planta Med. 1996, 62, 67-9. Naturally-occurring chalcones (shown below) are generally lipophilic and have moderate antibacterial activity. There have been solution-phase synthetic efforts directed at improving the antibacterial activity of naturally-occurring chalcones by increasing their water solubility. Nielsen, S. F.; Boesen, T.; Larsen, M.; Schonning, K.; Kromann, H., Antibacterial chalcones-bioisosteric replacement of the 4′-hydroxy group. Bioorg. Med. Chem. 2004, 12, 3047-3054; Nielsen, S. F.; Larsen, M.; Boesen, T.; Schonning, K.; Kromann, H., Cationic chalcone antibiotics. design, synthesis, and mechanism of action. J. Med. Chem. 2005, 48, 2667-2677.
[0000]
[0012] Chalcones should thus be a useful scaffold for making and assessing small molecules for antimicrobial activity. Furthermore, chalcones are adaptable to macroarray methods due to their relatively straightforward synthesis. The key feature of combinatorial chemistry—the speed at which a large number of diverse compounds can be generated—can be applied to the rapid discovery of new lead structures for use as antibacterial agents. The generation of small molecule macroarrays can streamline the process for generating diverse small molecule libraries with potential antibacterial activities, and can be used to identify novel antimicrobial agents, including antibacterial agents.
[0013] Backwell et al. WO 2008/016738 (published Feb. 7, 2008) have reported making chalcone-based small molecule macroarrays including chalcones, and cyanopyridine and methylpyrimidine derivatives of chalcones and the screening of the compound libraries made for antibacterial activity. These macroarrays employed planar cellulose membranes derivatized with a Wang-type linker. See: Bowman, et al. Tetrahedron 2006.
[0014] Bacterial cellular membranes have been identified as a possible target of antibacterial agents. Bacterial membranes are composed mostly of negatively charged phospholipid, phosphatidylglycerol. In contrast, eukaryotic cellular membranes comprise two different phospholipids, phosphatidylcholine and sphingomyelin. Zasloff, M., Antimicrobial peptides of multicellular organisms. Nature 2002, 415, 389-395. The differences in the composition of bacterial and eukaryotic membranes represent a unique structural difference that may be exploited as an antibacterial target. This is shown in the effectiveness of certain antimicrobial peptides, which are inherently present in humans, termed host-defense peptides. Host-defense peptides are short peptides (12-50 amino acids) that are found in a variety of living organisms including humans, and there have been synthetic examples of mimicking host-defense peptides for use as a potential antibacterial therapeutic. Schmitt, M. A.; Weisblum, B.; Gellman, S. H., Unexpected relationships between structure and function in alpha-, beta-peptides: antimicrobial foldamers with heterogeneous backbones. J. Am. Chem. Soc. 2004, 126, 6848-6849; Epand, R. F.; Raguse, T. L.; Gellman, S. H.; Epand, R. M., Antimicrobial 14-Helical beta-Peptides: Potent Bilayer Disrupting Agents. Biochemistry 2004, 43, 9527-9535; Schmitt, M. A.; Weisblum, B.; Gellman, S. H., Interplay among Folding, Sequence, and Lipophilicity in the Antibacterial and Hemolytic Activities of alpha/beta-Peptides. J. Am. Chem. Soc. 2007, 129, 417-428. Most of these amphipathic peptides contain structural features that are believed to contribute to their antibacterial activity, including regions of positively charged amino acid residues (for attraction to negatively charged bacterial membranes), and regions of hydrophobic amino acid residues (for insertion and subsequent disruption of the membrane).
[0015] Peptoids, or N-substituted glycine oligomers, are possible alternatives to antimicrobial peptides because they are resistant to proteolytic degradation and diverse libraries with a variety of sidechains can be generated using commercially available amines.
[0016] The present invention relates to additional methods for synthesis of small molecule macroarrays of chalcones and derivatives thereof and screening of such arrays for useful biological activities, including therapeutic activities and particularly antimicrobial activities. The invention relates in a second aspect to methods for covalently linking amino acids, peptides and/or peptoids to the chalcones and chalcone derivatives of such macroarrays to expand the potential for new antimicrobial compounds. The invention additionally relates to novel chalcones and chalcone derivatives exhibiting antimicrobial, particularly antibacterial activity.
BRIEF DESCRIPTION OF THE FIGURES
[0017] FIG. 1 illustrates a graphical representation of small molecule macroarray construction.
[0018] FIG. 2 provides a synthetic scheme showing Rink and Wang linking routes.
[0019] FIG. 3 provides a synthetic scheme showing the pathway for synthesis of library members.
[0020] FIG. 4 provides a list of materials used in the synthetic scheme of FIG. 3 for synthesis of library members.
[0021] FIG. 5 provides a synthetic scheme showing a pathway for chalcone/peptide synthesis.
[0022] FIG. 6 provides a synthetic scheme showing a pathway for peptoid/chalcone synthesis.
[0023] FIG. 7 provides a synthetic scheme showing an alternative pathway for peptide synthesis.
[0024] FIG. 8 shows an image of a TTC-stained agar-overlay assay showing active chalcones F17 and B19.
[0025] FIGS. 9A through 9O provide data showing the activity of chalcone library members.
[0026] FIGS. 10A through 10F provide data showing the activity of cyanopyridine library members.
[0027] FIGS. 11A and 11B provide data showing the activity of certain amino-pyrimidine library members.
[0028] FIGS. 12A and 12B provide data showing the activity of certain methyl-pyrimidine library members.
[0029] FIGS. 13A through 13E provide data showing dose responses for a number of library members.
[0030] FIGS. 14A through 14C provide data showing hemolytic activity of a number of library members.
[0031] FIG. 15 provides data showing membrane permeability for a number of compounds.
[0032] FIG. 16 illustrates the structures of a number of library members.
SUMMARY OF THE INVENTION
[0033] In one aspect, the invention relates to methods for generating small molecule macroarrays useful for screening of the molecules therein for antimicrobial activity. The methods employ a solid-support platform, preferably a planar cellulose support, which involves the use of a Rink amide linker (See FIG. 2 ) to attach small molecules of the library to the support. The use of this linker results in the formation of an amide group on small molecules released from the support (See FIG. 3 ). This group is polar and generally enhances the water-solubility of the small molecule which in turn can enhance the biological activity of the small molecule. The use of the Rink linker in synthesis of macroarrays and or microarrays allows additional chemical moieties to be covalently attached to the small molecules to enhance the diversity of molecules which can be synthesized and screened using the macroarray methods. In particular, the invention provides methods for making such small molecules linked to amino acids, peptides, N-substituted glycines, or peptoids (oligomers of N-substituted glycines). The attachment of such species can enhance and/or expand the biological activity of the small molecules to which they are attached and allow for targeting of the small molecules to specific sites in a cell or in an organism.
[0034] The use of the Rink linker for attachment of library compounds to the solid platform provides better mechanical properties for the on-support screening of the small molecule macroarrays.
[0035] The present invention provides versatile methods for screening compounds for antimicrobial activity, including antibacterial activity. The present methods are based on using combinatorial synthetic methods to generate arrays (e.g., macroarrays) comprising a large number of candidate molecules, identifying compounds of the array exhibiting antimicrobial activity and quantifying MICs of select compounds in the array. Structurally distinct candidate molecules are synthesized and bonded to distinct known locations (e.g., spots or regions) on a surface of a unitary substrate via linkers (i.e., linking groups attaching the candidates to the substrate). Candidate molecules are subsequently liberated from the substrate by cleaving the linkers and assayed for antibacterial activity by bringing the array into contact with a microbial culture, such as a bacterial culture or fungal culture. An advantage provided by the macroarray platform of the present screening methods is that qualitative and/or quantitative characterization of the antibacterial properties of large numbers of candidate compounds can be achieved on a relatively short time scale (i.e. days) using a single overlay visualization and/or quantification assay step.
[0036] In specific embodiments, the methods of this invention are applied to the synthesis of small molecule chalcones and derivatives thereof, particularly, cyanopyridine derivatives, alkyl pyrimidine derivatives and aminopyrimidine derivatives thereof.
[0037] In specific embodiments, the methods of this invention are applied to the synthesis of macroarrays for screening for antimicrobial activity. In more specific embodiments, the methods of this invention are applied to the synthesis of macroarrays for screening for antibacterial activity. In additional specific embodiments, the methods of this invention are used for screening macroarrays for activity against strains of the genus Staphylococcus and more particularly against strains of S. aureus and even more particularly against strains of Staphylococcus and S. aureus which exhibit methicillin-resistance (e.g., MRSA). The methods herein can be employed for the synthesis and identification of antibacterial compounds.
[0038] In another aspect, the present invention relates generally to compounds providing antibacterial therapeutic agents and preparations, and related methods of using and making antibacterial compounds. Antibacterial compounds of the present invention include chalcone, and alkylpyrimidine, aminopyrimidine and cyanopyridine derivatives of chalcones exhibiting antibacterial activity. In particular, certain antibacterial compounds of the invention exhibit minimum inhibitory concentrations (MIC) against a given bacterium similar to or less than conventional antibacterial compounds in wide use.
[0039] In an aspect, the present invention provides a composition of matter comprising a chalcone or chalcone derivative having Formula I:
[0000]
[0000] and salts, esters and solvates thereof,
where:
M is
[0040]
[0000] where R 11 is a an optionally substituted C1-C6 alkyl or NRR′, R 12 is an optionally substituted C1-C6 alkyl and R and R′ are independently selected from the group consisting of hydrogen, an optionally substituted C1-C6 alkyl, particularly a C1-C6 alkyl substituted with a C6-C13 aryl group, or an optionally substituted C3-C8 cycloalkyl, an optionally substituted C3 to C10 heterocycloalkyl or an optionally substituted C3 to C10 heterocycloalkene, each of which heterocycles contain 1, 2 or 3 heteroatoms (e.g., O, N or S), or an optionally substituted C6-C13 aryl group which includes an C1-C6 alkyl-substituted aryl group,
at least one of R 1 -R 5 is a —O—(CH 2 ) n —CO—NH 2 group, where n is an integer ranging from 1-6 (inclusive) and the remaining R 1 -R 5 are selected from hydrogen, halogen, hydroxyl, an amino group (—NH 2 , —NRR′), a —CN group, an azide group, a —NO 2 group, an optionally substituted C1-C12 alkyl, alkenyl or alkynyl group, an optionally substituted C6-C13 aryl group, an optionally substituted heterocycloalkyl C3-C8 (where the heteroatom(s) are N, O or S) and optionally substituted C1-C12 alkoxy or C6-C13 aryloxy groups;
at least one of R 6 -R 10 is a non-hydrogen substituent, where R 6 -R 10 are independently selected from the group consisting of hydrogen, halogen, hydroxyl, an amine group, a —CN group, an azide group, a —NO 2 group, an optionally substituted C1-C12 alkyl, C2-C12 alkenyl or C2-C12 alkynyl group, an optionally substituted C6-C13 aryl group, an optionally substituted C1-C12 alkoxy or C6-C13 aryloxy group, or a —O—(CH 2 ) m —CO—NH 2 group, where m is an integer ranging from 1-6 (inclusive).
[0041] In the above definitions, R and R′ are selected from hydrogen, C1-C6 alkyl (preferably C1-C3 alkyl), C3-C8 cycloalkyl, including cyclohexyl, C4-C8 heterocycloalkyl (heteroatom=N, O or S), and C6-C13 aryl.
[0042] Optional substitution, includes substitution with one or more halogens, —OH, —OR, —SH, —SR, —COOH, —COO − , —NRR′, —NRR′R″, —CONRR′, —NR—C(NRR′)═NR, —NR—C(NRR′)═NRR′, or C1-C3-alkyl groups, which in turn are optionally substituted with one or more halogens, —OH, —SH, —COOH, —COO − , C1-C3 alkoxy, —NRR′, —NRR′R″, —CONRR′, —NR—C(NRR′)═NR, or —NR—C(NRR′)═NRR′, where R, R′ and R″ are in particular hydrogen, or C1-C3 alkyl groups or C6-C13 aryl groups, which in turn can be substituted with one or more halogens, —OH, —SH, —COOH, —COO − , or C1-C3 alkoxy.
[0043] In another aspect, the invention provides, chalcones, alkyl-substituted cyanopyridines and alkyl-substituted alkyl or animopyrimidines of Formula X:
[0000]
[0000] and salts, esters and solvates thereof
where:
M is
[0044]
[0000] R 11 is a C1-C6 alkyl or NRR′ and R 12 is C 1 -C 6 alkyl and R and R′ are independently selected from the group consisting of hydrogen, C1-C6 alkyl which can be substituted with one or more of halogen, C6-C13 aryl group, a C3-C8 cycloalkyl, a C3 to C10 heterocycloalkyl, (where the heteroatom(s) are N, O or S) which contains 1 or 2 heteroatoms (e.g., O, N or S), or a C6-C13 aryl group which includes an C1-C6 alkyl-substituted aryl group;
at least one of R 1 -R 5 is selected from
[0000]
[0000] where:
each p, independently, is an integer from 1 to 6, inclusive, and r and s, independently are integers ranging from 1 to 100, inclusive, and more preferably r and s range from 2-10, 6-20, or 10-50 inclusive,
R aa is selected from hydrogen, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, C6-C13 aryl, C6-C13 aralkyl, C1-C8 ether, C1-C8 thioether, C3-C8 cycloalkyl or cycloalkenyl, C3-C10 heterocylic which contains 1, 2 or 3 heteroatoms (e.g., N, O or S), or a C3-C13 heteroaromatic group having 1, 2 or 3 heteroatoms (N, O or S) all of which groups are optionally substituted, particularly with one or more halogens, OH, OR, SH, SR, C1-C3-alkyl, —COOH, —COO − , —NRR′, —NRR′R″, —CONRR′, —NR—C(NRR′)═NR, and —NR—C(NRR′)═NRR′, where R, R′ and R″ are in particular hydrogen, and C1-C3 alkyl groups; and
R b is hydrogen, C1-C3 alkyl or R aa and R b together form an optionally substituted C3-C8 cycloalkyl or cycloalkenyl which optionally contains one or two heteroatoms (e.g., N, O or S), or R b is
[0000]
[0000] R p is selected from hydrogen, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, C6-C13 aryl, C1-C8 ether, C1-C8 thioether, C3-C8 cycloalkyl or cycloalkenyl group, which optionally contains one or two heteroatoms (e.g., N, O or S), and a C3-C13 heteroaromatic group having 1, 2 or 3 heteroatoms (N, O or S), all of which are optionally substituted, particularly with one or more halogens, OH, OR, SH, SR, C1-C3-alkyl, —COOH, —COO − , —NRR′, —NRR′R″, —CONRR′, —NR—C(NRR′)═NR, and —NR—C(NRR′)═NRR′ + , where R, R′ and R″ are in particular hydrogen, and optionally substituted C1-C3 alkyl groups; and one of R 13 or R 14 together with R aa form an optionally substituted C3-C8 cycloalkyl or cycloalkenyl group which optionally contains one or two heteroatoms (e.g., N, O or S);
each R 13 and R 14 are independently selected from hydrogen, C1-C6 alkyl which may be substituted with one or more halogens and benzyl or phenyl optionally substituted with one or more halogens, hydroxyl or C1-C3 alkyl groups;
remaining R 1 -R 10 are independently selected from the group consisting of hydrogen, hydroxy, halogen, nitro, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, aryl, aralkyl, aryloxy, arylthio, heteroaryl, heteroarylalkyl, heterocyclic, amino, aminoalkyl, aminoarylalkyl, hydroxyaminoalkyl, cycloalkylaminoalkyl, heteroarylaminoalkyl, heterocyclicaminoalkyl, hydroxyl, hydroxyalkyl, alditol, carbohydrate, polyol alkyl, —(O(CH 2 ) 2 ( 1-3 )O—C1-C3 alkyl, polyoxyalkylene, cycloalkyloxy, cycloalkylalkoxy, haloalkoxy, arylalkoxy, heteroarylalkoxy, heterocyclicoxy, heterocyclicalkoxy, —O(C(R) 2 ) 1-6 C(O)OR, —O(C(R) 2 ) 1-6 C(O)NRR′, amino, alkylamino, acylamino, dialkylamino, cycloalkylamino, arylamino, aralkylamino, heteroarylamino, heteroaralkylamino, heterocyclicamino, heterocyclicalkylamino, —NRR′, —NH(C(R) 2 ) 1-6 C(O)OR′, —NRC(O)R′, —NRC(O)OR′, —NRC(O)SR′, —NRSO 2 NRR′, —NHSO 2 R′, —NRSO2NRR′, —N(C(O)NRR′) 2 , —NRSO 2 R, —NRC(O)NRR′, thiol, alkylthio, haloalkylthio, arylthio, aralkylthio, heteroarylthio, heteroaralkylthio, heterocyclicthio, heterocyclicalkylthio, alkylsulfonyl, arylsulfonyl, haloalkylsulfonyl, —S(CRR′) 1-6 COOR, —S(CF 2 ) 1-6 COOR, —SO 2 NRR′, —SO 2 NROR, —SO 2 NR(O)NRR′, sulfonic acid, sulfonate, sulfate, sulfinic acid, sulfenic acid, cyano, tetrazol-5-yl, carboxy, —C(O)OR, —CONRR′, —C(O)NR(O)R, —CONRSO 2 R, —CONRSO 2 NRR′, —(CRR′) 1-6 (O)OH, —PO 2 H 2 , —PO 3 H 2 , —P(R)O 2 H, and phosphate, all of which can be optionally substituted by one or more selected from the group consisting of halo, alkyl, lower alkyl, alkenyl, cycloalkyl, acyl, hydroxy, hydroxyalkyl, heterocyclic, amino, aminoalkyl, alkoxy, oxo, cyano, carboxy, carboxyalkyl, alkoxycarbonyl, and groups formed by replacing one (preferably) or more non-adjacent CH 2 groups of an alkyl group with an —O-(ether)-S-(thioether), —NR—, —CO—, —SO—, SO 2 —, —NR—CO—, —NR—CO—NR—, —NR—CO—O—, —CO—O—, —CO—S—, —CO—, -aryl-, -aryl-O—, -aryl-S—, -heteroaryl-, or a -heterocyclic-moiety; and
optionally two R 1 -R 5 on adjacent ring carbons and/or two R 6 -R 10 on adjacent ring carbons taken together form a 3-8 member cycloalkyl, a 3-8 member heterocyclic group having 1-3 heteroatoms (e.g., N, O and/or S), a C6-C12 aryl, a 3-8 member heteroaryl group (having 1-3 heteroatoms (e.g., N, O and/or S) optionally substituted by one or more C1-C3 alky, acyl, alkoxycarbonylalkyl, carboxyalkyl, hydroxyalkyl, aminoalkyl, aminohydroxylalkyl, hydroxy, alkyl, carboxy, hydroxyalkyl, carboxyalkyl, amino, cyano, alkoxy, alkoxycarbonyl, acyl, oxo, —NRR′, cyano, carboxy, and halo.
[0045] In specific embodiments, R aa , R 13 or R 14 , independently of each other, are selected from one or more of hydrogen, methyl, isopropyl, isobutyl, sec-butyl, methylthioethyl, phenylmethyl, 4-OH-phenylmethyl, mercaptomethyl, hydroxylmethyl, 2-hydroxy-ethyl, 4-aminobutyl, carbamoylmethyl, 2-carbamoylethyl, carboxymethyl, 2-carboxyethyl, 1H-imidazol-4-yl-methyl, 3-guanidopropyl, or -(1H-indol-3-yl)methyl groups.
[0046] The present invention provides compounds exhibiting useful in vitro antibacterial activities against a variety of bacteria strains, including drug resistant bacterial strains, thereby providing antibacterial therapeutic agents and preparations useful for a range of important clinical applications.
[0047] In another aspect, the present invention provides combinatorial libraries of compounds, including candidate compounds for screening microbial activity including antibacterial activity. In an embodiment of this aspect of the present invention, the present invention provides one or more combinatorial libraries of chalcone compounds and/or derivative thereof having any one of the formulas herein.
[0048] In another aspect, the present invention provides pharmaceutical and therapeutic preparations comprising a therapeutically effective amount of one or more compounds of the present invention of Formula I and X above optionally in combination with a pharmaceutically acceptable carrier. In particular, pharmaceutical and therapeutic preparations of this invention comprise an amount or combined amount of one or more compounds of this invention effective for inhibiting the growth of a selected bacterium, particularly a bacterial pathogen and more particularly a bacterial human or veterinary pathogen. Compounds useful in the methods of this invention include pharmaceutically-acceptable salts and esters of the compounds of formulas herein. Compounds useful in the methods of this invention include pharmaceutically-acceptable prodrugs of the compounds of formulas herein.
[0049] Salts include any salts derived from the acids of the formulas herein which are acceptable for use in human or veterinary applications. The term esters refer to hydrolyzable esters of chalcone compounds, or chalcone derivatives of the present invention. The term ester includes, among others, esters of the compounds of the formulas herein (e.g., Formulas I and X), in which hydroxy groups have been converted to the corresponding esters with inorganic or organic acids such as nitric acid, sulphuric acid, phosphoric acid, citric acid, formic acid, maleic acid, acetic acid, succinic acid, tartaric acid, methanesulphonic acid, p-toluenesulphonic acid and the like, which are non toxic to living organisms. Salts and esters of this invention are prepared by methods that are well known in the art. Salts and esters of the compounds of the formulas herein are those which have the same or similar pharmaceutical or therapeutic (human or veterinary) properties as the chalcone compounds and/or chalcone derivatives of the present invention. Therapeutic and pharmaceutical preparations of the present invention comprise one or more of the compounds of the present invention in an amount or in a combined amount effective for obtaining the desired therapeutic benefit. Therapeutic and pharmaceutical preparations of the invention optionally further comprise a pharmaceutically acceptable carrier as known in the art.
[0050] In another aspect, the present invention provides a method of treating an infectious disease comprising administering to a patient in need of treatment, a composition comprising a compound of the present invention. In an embodiment, the infectious disease relates to that associated with an infectious agent comprising a bacterium. In an embodiment, the bacteria are Gram-positive bacteria. In a specific embodiment, the bacteria include one or more of Bacillus, Listeria, Staphylococcus, Streptococcus, Enterococcus, Corynebacterium, Propionibacterium and Clostridium . In a specific embodiment, the bacteria are one or more selected from the group consisting of S. aureus, S. epidermidis and B. subtilis . In a specific embodiment, the bacteria are one or more drug resistant bacteria.
[0051] In another aspect, the present invention provides methods of inhibiting growth of bacteria. In a specific embodiment of this aspect, a method of the present invention comprises the step of contacting the bacteria with an effective amount of one or more chalcone or chalcone derivative compounds of this invention which exhibit antibacterial activity. In an embodiment, the bacteria are Gram-positive bacteria. In a specific embodiment, the bacteria include one or more of Bacillus, Listeria, Staphylococcus, Streptococcus, Enterococcus, Corynebacterium, Propionibacterium and Clostridium . In a specific embodiment, the bacteria are one or more selected from the group consisting of S. aureus, S. epidermidis and B. subtilis . In a specific embodiment, the bacteria are one or more drug resistant bacteria. Methods of inhibiting bacteria of the present invention include methods useful for treatment of a subject (human or veterinary) and also include methods useful for inhibiting bacteria outside of a subject, such as use for sterilization and disinfection.
[0052] In another embodiment, the invention provides a medicament for treatment of a an infectious disease, particularly one associated with or caused by a bacterium. The medicament comprises a therapeutically effective amount of one or more compounds of this invention as illustrated in one or more formulas herein which compounds exhibit antimicrobial and/or antibacterial activity. The invention also provides a method for making this medicament which comprises combining a therapeutically effective amount of one or more compounds of this invention having antimicrobial and/or antibacterial activity with a selected pharmaceutical carrier appropriate for a given method of administration. The medicament may be an oral dosage form, an intravenous dosage form or any other art-recognized dosage form.
[0053] In another aspect, the present invention provides methods of synthesizing the compounds of the present invention, including methods of synthesizing chalcones, cyanopyridine derivatives of chalcones, alkylpyrimidine derivatives of chalcones, and aminopyrimidine derivatives of chalcones. In an embodiment, for example, the present invention includes methods of synthesizing compounds employing a Rink linker as illustrated in FIG. 3 herein.
[0054] In another aspect, the present invention provides methods of screening compounds, classes of compounds and combinatorial libraries of compounds for antimicrobial activity, including antibacterial activity. In an embodiment of this aspect, a method for screening a plurality of candidate compounds for antimicrobial activity of the present invention comprises the steps of: (i) providing a spatially-addressed array of the candidate compounds supported by a first unitary substrate, wherein the candidate compounds are individually addressed to selected positions of the substrate via linkers; (ii) contacting a microbial culture with the array or with a portion of the array transferred to a second unitary substrate in a manner retaining the relative positions of candidate compounds in the array, whereby candidate compounds having antimicrobial activity exhibit a zone of inhibition in the microbial culture; and (iii) identifying one or more positions in the array or transferred portion of the array corresponding to one or more candidate compounds exhibiting zones of inhibition. In the methods herein, the candidate compounds of the spatially addressed array are linked to that array employing a Rink linker as illustrated in FIG. 3 herein. Optionally, methods of this aspect of the present invention further comprise the step of transferring the portion of the array to a second unitary substrate in a manner retaining the relative positions of candidate compounds in the array. In some embodiments, this transfer step is carried out multiple times so as to generate a plurality of array samples for screening. In a specific embodiment, the invention provides a method of screening the plurality of candidate compounds for antibacterial activity wherein the microbial culture is a bacterial culture. Alternatively, the invention provides a method of screening the plurality of candidate compounds for antifungal activity wherein the microbial culture is a fungal culture. Useful arrays in the present methods include macroarrays and microarrays of candidate compounds.
[0055] The present invention includes methods using overlay assaying techniques wherein a microbial culture is provided in contact with the entire array or a portion thereof to provide effective, nearly simultaneous readout of the activities of a large number of candidate compounds. Overlay assaying techniques useful in these methods include, but are not limited to, techniques wherein an agar medium inoculated with bacteria is provided in contact with the array to provide screening of the antibacterial activities of candidate compounds of the array.
[0056] In some embodiments, the methods of the present invention further comprise the step of cleaving the linkers prior to the step of contacting the bacterial culture with the array or transferred portion of the array. This additional step facilitates achieving effective and biologically significant contact between compounds of the array and the microbial culture. Preferably, the step of cleaving the linkers connecting compounds of the array and the substrate is carried out in a way that does not substantially disrupt the position of individual compounds of the array on the substrate. In some embodiments, the screening methods further comprises the step of transferring the portion of the array to a second unitary substrate in a manner retaining the relative positions of candidate compounds in the array. Exemplary means of transferring a portion of the array in these embodiments include, but are not limited to, overlay transfer methods, such as positioning cleaved arrays between a solvent saturated surface and one or more dry cellulose sheets. An advantage of this embodiment of the present invention is that a single array may be used to generate a plurality of “copies” (i.e., transferred portions of the array which retain the spatially address nature of the compounds in the array) that can be screened to provide replicated assays.
[0057] Screening methods of the present invention may further comprise a number of optional steps. In an embodiment, for example, the method further comprises incubating the microbial culture, such as a bacteria culture, in contact with the array or transferred portion of the array. In an embodiment, for example, the method further comprises the step of measuring a zone of inhibition parameter exhibited by one or more candidate compounds of the array. Useful zone of inhibition parameters for the present methods include, but are not limited to, a diameter of inhibition, a radius of inhibition, and an area of inhibition. In an embodiment, for example, the method further comprises the step of contacting the bacterial culture with a visualization agent, whereby the visualization agent is capable of differentiating between zones of inhibition and zones of no activity. Useful visualization agents include, but are not limited to, redox indicators such as triphenyl tetrazolium chloride capable of providing clear and reproducible visualization of areas of live and dead bacteria for the measuring one or more zone of inhibition parameters.
[0058] Preferably for many applications, candidate compounds are linked to the substrate in a manner such that they can be non-destructively cleaved from the first unitary substrate. The choice of linker and mechanism of cleavage from the substrate may affect the composition of candidate compounds released from the substrate via cleavage reactions. When the Rink linker is used, for example, cleavage of linkers results in candidate compounds having an —CO—NH 2 group introduced through the linking chemistry.
[0059] Substrates useful in the present methods include planar (2D) substrates and three-dimensional substrates. Three-dimensional substrates include beaded materials, such as beaded cellulose, and other useful materials such as tissue engineering scaffolds. A range of substrate compositions are useful in the present invention including, but not limited to, cellulose substrate, nylon substrate, polypropylene substrate, polycarbonate substrate, glass substrate, gold substrate, silicone substrate or amorphous carbon substrate. In some embodiments, the unitary substrate supporting the arrays of this invention is a planar substrate.
[0060] In some methods candidate compounds are synthesized in an array bound to a surface. The candidate compounds are typically linked to the surface by a linker group, preferably for many screening applications a cleavable linker group. In the methods described herein a Rink Linker is employed. The methods of this invention are particularly useful when practiced with macroarrays. However, the methods can be practiced employing microarrays.
DETAILED DESCRIPTION OF THE INVENTION
[0061] All technical and scientific terms used herein have the broadest meanings as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0062] The present invention relates in part to libraries of compounds prepared in array form for testing for biological activity. The array format of the methods herein is particularly suited to assessing activity of library compounds for antimicrobial activity, including anti-fungal, anti-yeast, anti-protozoan, and antibacterial activity. Compounds of libraries herein exhibit antimicrobial activity including antibacterial activity.
[0063] For example, the present invention provides in one aspect a composition of matter comprising a chalcone or chalcone derivative having Formula I:
[0000]
[0000] and salts, esters and solvates thereof,
where:
M is
[0064]
[0000] where R 11 is a C1-C6 alkyl or NRR′ and R 12 is C 1 -C 6 alkyl and R and R′ are independently selected from the group consisting of hydrogen, C1-C6 alkyl which can be substituted with a C6-C13 aryl group, a C1-C8 cycloalkyl, a heterocycloalkyl C3-C8 (where the heteroatom(s) are N, O or S) which optionally contains 1 or 2 heteroatoms (e.g., O, N or S), or a C6-C13 aryl group which includes an C1-C6 alkyl-substituted aryl group,
one of R 1 -R 5 is a —O—(CH 2 ) n —CO—NH 2 group, where n is 1-6 and the remaining R 1 -R 5 are selected from hydrogen, halogen, hydroxyl, an amino group (—NH 2 , —NRR′), a —CN group, an azide group, a —NO 2 group, an optionally substituted C1-C12 alkyl, alkenyl or alkynyl group, an optionally substituted C6-C13 aryl group, an optionally substituted heterocycloalkyl C3-C8 (where the heteroatom(s) are N, O or S) and optionally substituted C1-C12 alkoxy or C6-C13 aryloxy groups;
wherein at least one of R 6 -R 10 is a non-hydrogen substituent and where R 6 -R 10 are independently selected from the group consisting of hydrogen, halogen, hydroxyl, an amine group, a —CN group, an azide group, a —NO 2 group, an optionally substituted C1-C12 alkyl, alkenyl or alkynyl group, an optionally substituted C6-C13 aryl group, an optionally substituted C1-C12 alkoxy or C6-C13 aryloxy group, and a —O—(CH 2 ) m —CO—NH 2 group, where m is 1-6.
[0065] More specifically the invention provides a chalcone compound of Formula II:
[0000]
[0000] and salts, esters and solvates thereof
wherein one of R 1 -R 5 is a —O—(CH 2 ) n —CO—NH 2 group where n is 1-6 and the remaining R 1 -R 5 are selected from hydrogen, halogen, hydroxyl, an amine group (—NH 2 , —NRR′), a —CN group, an azide group, a —NO 2 group, optionally substituted C1-C12 alkyl, alkenyl or alkynyl groups, optionally substituted C6-C13 aryl groups, optionally substituted heterocycloalkyl C3-C8 (where the heteroatom(s) are N, O or S) and optionally substituted C1-C12 alkoxy or C6-C13 aryloxy groups,
wherein at least one of R 6 -R 10 is a non-hydrogen substituent and where R 6 to R 10 are selected from the group consisting of from hydrogen, halogen, hydroxyl, an amine group, a —CN group, an azide group, a —NO 2 group, optionally substituted C1-C12 alkyl, alkenyl or alkynyl groups, optionally substituted C6-C13 aryl groups, optionally substituted C1-C12 alkoxy or C6-C13 aryloxy groups, and a —O—(CH 2 ) m —CO—NH 2 group, where m is 1-6.
[0066] Additionally the invention provides compounds of Formulas III and IV:
[0000]
[0000] where variables are as defined above, and where R 11 is more preferably an optionally substituted C1-C3 alkyl or an —NH 2 group and R 12 is more preferably a C1-C3 alkyl or hydrogen.
[0067] In specific embodiments of the compounds of Formulas I-IV, X and XI (below), one, two or three of R 6 -R 10 are halogens, including one, two or three bromines, one, two or three chlorines or one, two or three fluorines. In a specific embodiment the remaining R 6 -R 10 are hydrogens.
[0068] In specific embodiments of the compounds of Formulas I-IV, X and XI, one, two or three of R 6 -R 10 are C1-C6 haloalkyl groups, including one, two or three C1-C6 perfluoralkyl groups, one, two or three C1-C3 perfluoralkyl groups or one, two or three trifluoromethyl groups and the remaining R 6 -R 10 are hydrogens.
[0069] In specific embodiments of the compounds of Formulas I-IV, X and XI, R 6 , R 7 and R 9 or R 10 are halogens or haloalkyl groups, particularly bromines, chlorines or fluorines and particularly trifluoromethyl groups. In a specific embodiment the remaining R 8 and R 9 or R 10 are hydrogens.
[0070] In specific embodiments of the compounds of Formulas I-IV, X and XI, R 6 , R 7 and R 9 or R 10 are halogens, particularly bromines, chlorines or fluorines. In a specific embodiment the remaining R 8 and R 9 or R 10 are hydrogens.
[0071] In specific embodiments of the compounds of Formulas I-IV, X and XI, R 6 , R 7 and R 9 or R 10 are C1-C6 fluoroalkyl groups, more specifically perfluoroalkyl group, and even more specifically trifluoromethyl groups. In a specific embodiment the remaining R 8 and R 9 or R 10 are hydrogens.
[0072] In specific embodiments of the compounds of Formulas I-IV, X and XI, R 11 and R 12 are C1-C3 alkyl or hydrogen.
[0073] In specific embodiments of the compounds of Formulas I-IV, X and XI, R 6 or R 7 or R 8 is a halogen or a C1-C3 perfluoralkyl group. In a specific embodiment the remaining R 6 -R 10 groups are hydrogens.
[0074] In specific embodiments of the compounds of Formulas I-IV, X and XI, one of R 1 -R 5 is an OH, C1-C3 alkoxy, a phenoxy, a benzyloxy, —COC1-C3 alkyl, C1-C6 haloalkyl, or halo. In another specific embodiment of the compounds of Formulas I-IV, X and XI, one of R 1 -R 5 is an OH, methoxy, trifluoromethyl, bromo, fluoro or chloro group.
[0075] In specific embodiments of the compounds of Formulas I-IV, one of R 1 , R 2 or R 3 is —O—(CH 2 ) n —CO—NH 2 , where n is 1-6. In other embodiments, R 1 is —O—(CH 2 ) n —CO—NH 2 , where n is 1-6. In other embodiments, R 2 is —O—(CH 2 ) n —CO—NH 2 , where n is 1-6. In other embodiments one of R 1 , R 2 or R 3 is —O—CH 2 CO—NH 2 . In other embodiments, R 1 is —O—CH 2 —CO—NH 2 . In other embodiments, R 2 is —O—CH 2 —CO—NH 2 . In other embodiments, all other R 1 -R 5 are hydrogens.
[0076] In specific embodiments of the compounds of Formulas I-IV, R 1 is —O—(CH 2 ) n —CO—NH 2 , where n is 1-6 and R 4 is a halogen. In specific embodiments, all of R 2 , R 3 and R 5 are hydrogens.
[0077] In specific embodiments of the compounds of Formulas I-IV, R 1 is —O—(CH 2 ) n —CO—NH 2 , where n is 1-6 and all of R 2 , R 3 , R 4 and R 5 are hydrogens.
[0078] In specific embodiments of the compounds of Formulas I-IV, R 3 is —O—(CH 2 ) n —CO—NH 2 , where n is 1-6 and R 4 is a C1-C3 alkyl or perfluoralkyl. In specific embodiments, all of R 1 , R 2 and R 5 are hydrogens.
[0079] In specific embodiments of the compounds of Formulas I-IV and X, none of R 1 -R 10 is an OH group. In specific embodiments of the compounds of Formulas I-IV and X, none of R 1 -R 5 is an OH group. In specific embodiments of the compounds of Formulas I-IV and X, none of R 6 -R 10 is an OH group.
[0080] The invention provides antimicrobial, particularly antibacterial, compounds including F17, F19, F11, F12, F13, F6, B17, B19, or B14 (see FIGS. 3 , 4 and 16 for naming convention).
[0081] The invention provides antimicrobial, particularly antibacterial, compounds including F5, F7, F9, F18. F26 and D27.
[0082] The invention provides antimicrobial, particularly antibacterial, compounds including F8. F10, F22, F25, E6 and B27.
[0083] In another aspect the invention provides compounds of Formula X:
[0000]
[0000] and salts, esters and solvates thereof
where:
M is
[0084]
[0000] R 11 is a C1-C6 alkyl or NRR′ and R 12 is C 1 -C 6 alkyl and R and R′ are independently selected from the group consisting of hydrogen, C1-C6 alkyl which can be substituted with one or more of halogen, C6-C13 aryl group, a C3-C8 cycloalkyl, a C3 to C10 heterocycloalkyl, (where the heteroatom(s) are N, O or S) which contains 1 or 2 heteroatoms (e.g., O, N or S), or a C6-C13 aryl group which includes an C1-C6 alkyl-substituted aryl group;
at least one of R 1 -R 5 is selected from
[0000]
[0000] wherein p is an integer 1-6;
[0000]
[0000] (including NH 2 -peptide-CO—(CH 2 ) p —O—), where p is an integer from 1 to 6, r is an integer ranging from 1 to 100 and more preferably from 10 to 50,
R aa is selected from hydrogen, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, C6-C13 aryl, C6-C13 aralkyl, C1-C8 ether, C1-C8 thioether, C3-C8 cycloalkyl or cycloalkenyl which optionally contains one or two heteroatoms (e.g., N, O or S), and a C3-C13 heteroaromatic group having 1, 2 or 3 heteroatoms (N, O or S) all of which are optionally substituted, particularly with one or more halogens, OH, OR, SH, SR, C1-C3-alkyl, —COOH, —COO − , —NRR′, —NRR′R″, —CONRR′, —NR—C(NRR′)═NR, and —NR—C(NRR′)═NRR′ + , where R, R′ and R″ are in particular hydrogen, and C1-C3 alkyl groups; R b is hydrogen, C1-C3 alkyl or R aa and R b together form an optionally substituted C3-C8 cycloalkyl or cycloalkenyl which optionally contains one or two heteroatoms (e.g., N, O or S),
[0000]
[0000] where p is 1-6, s is an integer ranging from 1 to 100 and more preferably from 10 to 50;
R p is selected from hydrogen, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, C6-C13 aryl, C1-C8 ether, C1-C8 thioether, C3-C8 cycloalkyl or cycloalkenyl group which optionally contains one or two heteroatoms (e.g., N, O or S), and a C3-C13 heteroaromatic group having 1, 2 or 3 heteroatoms (N, O or S), all of which are optionally substituted, particularly with one or more halogens, OH, OR, SH, SR, C1-C3 alkyl, —COOH, —COO − , —NRR′, —NRR′R″, —CONRR′, —NR—C(NRR′)═NR, and —NR—C(NRR′)═NRR′ + , where R, R′ and R″ are in particular hydrogen, and C1-C3 alkyl groups; and one of R 13 or R 14 together with R aa form an optionally substituted C3-C8 cycloalkyl or cycloalkenyl group which optionally contains one or two heteroatoms (e.g., N, O or S);
R 13 and R 14 are independently selected from hydrogen, C1-C6 alkyl which may be substituted with one or more halogens and benzyl or phenyl optionally substituted with one or more halogens, hydroxyl or C1-C3 alkyl groups;
R 1 -R 10 are independently selected from the group consisting of hydrogen, hydroxy, halogen, nitro, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, aryl, aralkyl, aryloxy, arylthio, heteroaryl, heteroarylalkyl, heterocyclic, amino, aminoalkyl, aminoarylalkyl, hydroxyaminoalkyl, cycloalkylaminoalkyl, heteroarylaminoalkyl, heterocyclicaminoalkyl, hydroxyl, hydroxyalkyl, alditol, carbohydrate, polyol alkyl, —(O(CH 2 ) 2 ( 1-3 )O—C1-C3 alkyl, polyoxyalkylene, cycloalkyloxy, cycloalkylalkoxy, haloalkoxy, arylalkoxy, heteroarylalkoxy, heterocyclicoxy, heterocyclicalkoxy, —O(C(R) 2 ) 1-6 C(O)OR, —(C(R) 2 ) 1-6 C(O)NRR′, amino, alkylamino, acylamino, dialkylamino, cycloalkylamino, arylamino, aralkylamino, heteroarylamino, heteroaralkylamino, heterocyclicamino, heterocyclicalkylamino, —NRR′, —NH(C(R) 2 ) 1-6 C(O)OR′, —NRC(O)R′, —NRC(O)OR′, —NRC(O)SR, —NRSO 2 NRR′, —NHSO 2 R′, —NRSO2NRR′, —N(C(O)NRR′) 2 , —NRSO 2 R, —NRC(O)NRR′, thiol, alkylthio, haloalkylthio, arylthio, aralkylthio, heteroarylthio, heteroaralkylthio, heterocyclicthio, heterocyclicalkylthio, alkylsulfonyl, arylsulfonyl, haloalkylsulfonyl, —S(CRR′) 1-6 COOR, —S(CF 2 ) 1-6 COOR, —SO 2 NRR′, —SO 2 NROR, —SO 2 NR(O)NRR′, sulfonic acid, sulfonate, sulfate, sulfinic acid, sulfenic acid, cyano, tetrazol-5-yl, carboxy, —C(O)OR, —CONRR′, —C(O)NR(O)R, —CONRSO 2 R, —ONRSO 2 NRR′, —(CRR′) 1-6 (O)OH, —PO 2 H 2 , —PO 3 H 2 , —P(R)O 2 H, and phosphate, all of which can be optionally substituted by one or more selected from the group consisting of halo, alkyl, lower alkyl, alkenyl, cycloalkyl, acyl, hydroxy, hydroxyalkyl, heterocyclic, amino, aminoalkyl, alkoxy, oxo, cyano, carboxy, carboxyalkyl, alkoxycarbonyl, and groups formed by replacing one (preferably) or more non-adjacent CH 2 groups of an alkyl group with an —O-(ether)-S-(thioether), —NR—, —CO—, —SO—, SO 2 —, —NR—CO—, —NR—CO—R—, —NR—CO—O—, —CO—O—, —CO—S—, —CO—, -aryl-, -aryl-O—, -aryl-S—, -heteroaryl-, or a -heterocyclic-moiety;
two R 1 -R 5 on adjacent ring carbons and/or two R 6 -R 10 on adjacent ring carbons taken together form a 3-8 member cycloalkyl, a 3-8 member heterocyclic group having 1-3 heteroatoms (e.g., N, O and/or S), a C6-C12 aryl, a 3-8 member heteroaryl group (having 1-3 heteroatoms (e.g., N, O and/or S) optionally substituted by one or more C1-C3 alky, acyl, alkoxycarbonylalkyl, carboxyalkyl, hydroxyalkyl, aminoalkyl, aminohydroxylalkyl, hydroxy, alkyl, carboxy, hydroxyalkyl, carboxyalkyl, amino, cyano, alkoxy, alkoxycarbonyl, acyl, oxo, —NRR′, cyano, carboxy, and halo.
[0085] The invention provides compounds of Formula XI:
[0000]
[0000] where R 1 -R 10 are as defined for Formula X.
[0086] In a specific embodiment of Formulas X and XI, R 1 -R 10 groups other than those which comprise amino acid, peptide, N-substituted glycines or peptoids, are selected from halogens, hydroxyl, C1-C3 alkyl, C1-C6 haloalkyl, —COC1-C3 alkyl, phenoxy, and phenyl.
[0087] In specific embodiments of Formulas X and XI, R 1 , R 2 , R 3 or R 6 is selected from:
[0000]
[0000] wherein p 1, 2 or 3;
[0000]
[0000] (including NH 2 -peptide-CO—(CH 2 ) p —O—), where p is 1, 2 or 3, and r is an integer ranging from 1 to 100 and more preferably from 10 to 50, and each R b is hydrogen or linked to R aa and each R aa alone or in combination with R b are amino acids side groups of amino acids found in proteins and in particular the 20 common amino acids (Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Ser, Thr, Trp, Tyr, and Val);
[0000]
[0000] where p is 1, 2 or 3; s is an integer ranging from 1 to 100 and more preferably from 10 to 50; R p is selected from hydrogen, C1-C8 alkyl, alkenyl, or alkynyl, C6-C13 aryl, C3-C8 cycloalkyl which optionally contains one or two heteroatoms (e.g., N, O or S), an C1-C8 alkyl amino group, a C1-C8 alkylamide, —(CH 2 ) m NRR′, —(CH 2 ) m CONRR′, —(CH 2 ) m —NR—C(NRR′)═NR, where m is an integer ranging from 1-6, and R, R′ are in particular hydrogen, and C1-C3 alkyl groups; and R 13 or R 14 are hydrogen except that one of R 13 or R 14 together with R p can form an optionally substituted C3-C8 cycloalkyl or cycloalkenyl group which optionally contains one or two heteroatoms (e.g., N, O or S);
[0000]
[0000] where Raa is as defined above; or
[0000]
[0000] where r is an integer ranging from 1-100 (also 10-50) and Raa is as defined above.
[0088] In a specific embodiment of Formulas X and XI which contains
[0000]
[0000] the selected R aa and R b form a peptide that is amphipathic, In another embodiment, the peptide formed by the combined R aa and R b is a host defense peptide as is known in the art. Peptides in this group may contain 1-10, 20-30, 25-40, or 50-100 amino acids,
[0089] In a specific embodiment of Formulas X and XI which contains
[0000]
[0000] and is 10 to 50, the combined R aa and R b form a peptide that is amphipathic. In another embodiment, the peptide formed by the combined R aa and R b is a host defense peptide as is known in the art. Peptides in this group may contain 1-10, 20-30, or 25-40 amino acids.
[0090] In additional specific embodiments of Formulas X and XI which contains
[0000]
[0000] the independently selected Raa and Rb groups together form a peptide that is cationic, e.g, that is rich in Lys, Arg and/or His amino acid groups. More specifically, in an embodiment, the peptide is one wherein 50% of more of the R aa and R b groups are those of cationic amino acids, for example Lys, Arg and/or His. More specifically, in an embodiment, the peptide is one wherein 75% of more of the R aa and R b groups are those of cationic amino acids, for example Lys, Arg and/or His In more specific embodiments, the peptide formed has only Lys and/or Arg groups. In more specific embodiments, the peptide formed has only Lys and/or Arg groups and r is 1-10, 2-10, 3-10, 6-10 or 6-20. In more specific embodiments, the peptide formed has only His groups. In more specific embodiments, the peptide formed has only His groups and r is 1-10, 2-10, 3-10, 6-10 or 6-20. In specific embodiments, the peptides are formed from L-amino acids. In other embodiments, the peptides are formed from D-amino acids.
[0091] In additional specific embodiments of Formulas X and XI which contains
[0000]
[0000] the independently selected Raa and Rb groups together form a peptide that is cationic but which has hydrophobic and/or aromatic peptide regions flanking the cationic regions. For example, the peptide can contains a poly Arg, poly Lys or poly His portion, ranging in size from 6-20 amino acids, with one or two flanking region having 2 or more, including 2-10 or 2-20, hydrophobic or aromatic amino acids. In specific embodiments, the peptides are formed from L-amino acids. In other embodiments, the peptides are formed from D-amino acids.
[0092] In any of the formulas herein where appropriate any of the variable groups can comprise a protecting group.
[0093] As used herein optional substitution means substitution with one or more non-hydrogen substituents selected from the group consisting of hydroxyl group, halide, —CN group, —NO 2 group, a-NH 2 , an amine group (—NRR′), an amide group (—NR—CO—R′ or —CO—NR′R), an acyl group (—CO—R), thiol, substituted or unsubstituted C1-C6 alkyl, akenyl or alkynyl groups, substituted or unsubstituted C6-C13 aryl groups, substituted or unsubstituted C1-C6 alkoxy groups, substituted or unsubstituted C6-C13 aryloxy groups, substituted or unsubstituted C3-C12 heterocyclic groups where the heteroatoms are N, O or S. Non-hydrogen substitution for substituents mean substitution with one or more non-hydrogen groups selected from hydroxyl, halogen, —CN, —NO 2 , —NR″R′″, unsubstituted C1-C3 alkyl, unsubstituted phenyl or benzyl groups.
[0094] In the above definitions, R and R′ are selected from hydrogen, C1-C6 alkyl (preferably C1-C3 alkyl), C3-C8 cycloalkyl, C4-C8 heterocycloalkyl (heteroatom=N, O or S), and C6-C13 aryl; and R″ and R′″ are selected from hydrogen, C1-C6 alkyl (preferably C1-C3 alkyl), C3-C8 cycloalkyl, C4-C8 heterocycloalkyl (heteroatom=N, O or S), and C6-C13 aryl.
[0095] In addition, hereinafter, the following definitions apply:
[0096] As used herein, the term “array” refers to an ordered arrangement of structural elements, such as an ordered arrangement of individually addressed and spatially localized elements. Arrays useful in the present invention include arrays of containment structures and/or containment regions, such as fluid containment structures or regions, provided in a preselected, spatially organized manner. In some embodiments, for example, different containment structures and/or regions in an array are physically separated from each other and hold preselected materials, such as the reactants and/or products of chemical reactions, for example candidate compounds for screening of antimicrobial activity.
[0097] Arrays of the present invention include “microarrays” and “macroarrays” which comprise an ordered arrangement of containment structures and/or containment regions capable of providing, confining and/or holding reactants, products, solvent and/or catalysts corresponding to one or more chemical reactions, reaction conditions and/or screening conditions. In some embodiments, a portion of the reactants and/or products confined in a containment structure/region of a microarray or macroarray are immobilized, for example by spatially localized conjugation to a selected region of containment structure or region. Microarrays and macroarrays of the present invention, for example, are capable of providing an organized arrangement of containment structures and/or regions, wherein different containment structures and/or regions are useful for providing, confining and/or holding preselected combinations of reactants, products and/or candidate compounds having well defined and selected compositions, concentrations and phases. Containment structures and/or regions of microarrays and macroarrays are also useful for providing, confining and/or holding the products of chemical reactions. In some embodiments, for example, each containment structure and/or region of the microarrays and macroarrays is physically separated and contains the product of a different chemical reaction or a chemical reaction carried out under different reaction conditions.
[0098] The terms “microarray” and “macroarray” are used herein in a manner consist with the art. In some embodiments, a microarray comprises a plurality of containment structures or regions having at least one microsized (e.g., 1 to 1000s of microns) or sub-microsized (e.g., less than 1 micron) physical dimension. In some contexts, containment structures/regions of a microarray are smaller than containment structures/regions of a macroarray. In some contexts, containment structures/regions of a microarray are provided in a higher density than containment structures/regions of a macroarray. In some contexts, the number of containment structures/regions of a microarray is larger than the number of containment structures/regions of a macroarray. In specific embodiments, the invention provides macroarrays produced by SPOT synthesis are described herein and as known in the art. Macroarrays in the context of the present invention which are arrays of candidate compound for screening are prepared such that each compound member of the array (each spatially-localized compound) is present in an amount sufficient to allow its removal form the array for further analysis, for example, to measure spectral properties or to obtain confirmatory structural analysis (e.g., by mass spectroscopic analysis or NMR analysis). As will be understood by one having ordinary skill in the art may different microarray and macroarray formats are useable in the present invention including, but not limited to, standard 96, 384 or 1536 microarray configurations.
[0099] As defined herein, “contacting” means that a compound used in the present invention is provided such that is capable of making physical contact with another element, such as a microorganism, a microbial culture or a substrate. In another embodiment, the term “contacting” means that the compound used in the present invention is introduced into a subject receiving treatment, and the compound is allowed to come in contact in vivo.
[0100] Alkyl groups include straight-chain, branched and cyclic alkyl groups. Alkyl groups include those having from 1 to 30 carbon atoms. Alkyl groups include small alkyl groups having 1 to 3 carbon atoms. Alkyl groups include medium length alkyl groups having from 4-10 carbon atoms. Alkyl groups include long alkyl groups having more than 10 carbon atoms, particularly those having 10-30 carbon atoms. Cyclic alkyl groups include those having one or more rings. Cyclic alkyl groups include those having a 3-, 4-, 5-, 6-, 7-, 8-, 9- or 10-member carbon ring and particularly those having a 3-, 4-, 5-, 6-, or 7-member ring. The carbon rings in cyclic alkyl groups can also carry alkyl groups. Cyclic alkyl groups can include bicyclic and tricyclic alkyl groups. Alkyl groups are optionally substituted. Substituted alkyl groups include among others those which are substituted with aryl groups, which in turn can be optionally substituted. Specific alkyl groups include methyl, ethyl, n-propyl, iso-propyl, cyclopropyl, n-butyl, s-butyl, t-butyl, cyclobutyl, n-pentyl, branched-pentyl, cyclopentyl, n-hexyl, branched hexyl, and cyclohexyl groups, all of which are optionally substituted. Substituted alkyl groups include fully halogenated or semihalogenated alkyl groups, such as alkyl groups having one or more hydrogens replaced with one or more fluorine atoms, chlorine atoms, bromine atoms and/or iodine atoms. Substituted alkyl groups include fully fluorinated or semifluorinated alkyl groups, such as alkyl groups having one or more hydrogens replaced with one or more fluorine atoms. An alkoxyl group is an alkyl group linked to oxygen and can be represented by the formula R—O.
[0101] Alkenyl groups include straight-chain, branched and cyclic alkenyl groups. Alkenyl groups include those having 1, 2 or more double bonds and those in which two or more of the double bonds are conjugated double bonds. Alkenyl groups include those having from 2 to 20 carbon atoms. Alkenyl groups include small alkenyl groups having 2 to 3 carbon atoms. Alkenyl groups include medium length alkenyl groups having from 4-10 carbon atoms. Alkenyl groups include long alkenyl groups having more than 10 carbon atoms, particularly those having 10-20 carbon atoms. Cyclic alkenyl groups include those having one or more rings. Cyclic alkenyl groups include those in which a double bond is in the ring or in an alkenyl group attached to a ring. Cyclic alkenyl groups include those having a 3-, 4-, 5-, 6-, 7-, 8-, 9- or 10-member carbon ring and particularly those having a 3-, 4-, 5-, 6- or 7-member ring. The carbon rings in cyclic alkenyl groups can also carry alkyl groups. Cyclic alkenyl groups can include bicyclic and tricyclic alkyl groups. Alkenyl groups are optionally substituted. Substituted alkenyl groups include among others those which are substituted with alkyl or aryl groups, which groups in turn can be optionally substituted. Specific alkenyl groups include ethenyl, prop-1-enyl, prop-2-enyl, cycloprop-1-enyl, but-1-enyl, but-2-enyl, cyclobut-1-enyl, cyclobut-2-enyl, pent-1-enyl, pent-2-enyl, branched pentenyl, cyclopent-1-enyl, hex-1-enyl, branched hexenyl, cyclohexenyl, all of which are optionally substituted. Substituted alkenyl groups include fully halogenated or semihalogenated alkenyl groups, such as alkenyl groups having one or more hydrogens replaced with one or more fluorine atoms, chlorine atoms, bromine atoms and/or iodine atoms. Substituted alkenyl groups include fully fluorinated or semifluorinated alkenyl groups, such as alkenyl groups having one or more hydrogens replaced with one or more fluorine atoms.
[0102] Aryl groups include groups having one or more 5- or 6-member aromatic or heteroaromatic rings. Aryl groups can contain one or more fused aromatic rings. Heteroaromatic rings can include one or more N, O, or S atoms in the ring. Heteroaromatic rings can include those with one, two or three N, those with one or two O, and those with one or two S, or combinations of one or two or three N, O or S. Aryl groups are optionally substituted. Substituted aryl groups include among others those which are substituted with alkyl or alkenyl groups, which groups in turn can be optionally substituted. Specific aryl groups include phenyl groups, biphenyl groups, pyridinyl groups, and naphthyl groups, all of which are optionally substituted. Substituted aryl groups include fully halogenated or semihalogenated aryl groups, such as aryl groups having one or more hydrogens replaced with one or more fluorine atoms, chlorine atoms, bromine atoms and/or iodine atoms. Substituted aryl groups include fully fluorinated or semifluorinated aryl groups, such as aryl groups having one or more hydrogens replaced with one or more fluorine atoms.
[0103] Arylalkyl groups are alkyl groups substituted with one or more aryl groups wherein the alkyl groups optionally carry additional substituents and the aryl groups are optionally substituted. Specific alkylaryl groups are phenyl-substituted alkyl groups, e.g., phenylmethyl groups. Alkylaryl groups are alternatively described as aryl groups substituted with one or more alkyl groups wherein the alkyl groups optionally carry additional substituents and the aryl groups are optionally substituted. Specific alkylaryl groups are alkyl-substituted phenyl groups such as methylphenyl. Substituted arylalkyl groups include fully halogenated or semihalogenated arylalkyl groups, such as arylalkyl groups having one or more alkyl and/or aryl having one or more hydrogens replaced with one or more fluorine atoms, chlorine atoms, bromine atoms and/or iodine atoms.
[0104] Optional substitution of any alkyl, alkenyl and aryl groups includes substitution with one or more of the following substituents: halogens, —CN, —COOR, —OR, —COR, —OCOOR, —CON(R) 2 , —OCON(R) 2 , —N(R) 2 , —NO 2 , —SR, —SO 2 R, —SO 2 N(R) 2 or —SOR groups. Optional substitution of alkyl groups includes substitution with one or more alkenyl groups, aryl groups or both, wherein the alkenyl groups or aryl groups are optionally substituted. Optional substitution of alkenyl groups includes substitution with one or more alkyl groups, aryl groups, or both, wherein the alkyl groups or aryl groups are optionally substituted. Optional substitution of aryl groups includes substitution of the aryl ring with one or more alkyl groups, alkenyl groups, or both, wherein the alkyl groups or alkenyl groups are optionally substituted.
[0105] Optional substituents for alkyl, alkenyl and aryl groups include among others:
[0000] —COOR where R is a hydrogen or an alkyl group or an aryl group and more specifically where R is methyl, ethyl, propyl, butyl, or phenyl groups all of which are optionally substituted;
—COR where R is a hydrogen, or an alkyl group or an aryl groups and more specifically where R is methyl, ethyl, propyl, butyl, or phenyl groups all of which groups are optionally substituted;
—CON(R) 2 where each R, independently of each other R, is a hydrogen or an alkyl group or an aryl group and more specifically where R is methyl, ethyl, propyl, butyl, or phenyl groups all of which groups are optionally substituted; R and R can form a ring which may contain one or more double bonds;
—OCON(R) 2 where each R, independently of each other R, is a hydrogen or an alkyl group or an aryl group and more specifically where R is methyl, ethyl, propyl, butyl, or phenyl groups all of which groups are optionally substituted; R and R can form a ring which may contain one or more double bonds;
—N(R) 2 where each R, independently of each other R, is a hydrogen, or an alkyl group, acyl group or an aryl group and more specifically where R is methyl, ethyl, propyl, butyl, or phenyl or acetyl groups all of which are optionally substituted; or R and R can form a ring which may contain one or more double bonds;
—SR, —SO 2 R, or —SOR where R is an alkyl group or an aryl groups and more specifically where R is methyl, ethyl, propyl, butyl, phenyl groups all of which are optionally substituted; for —SR, R can be hydrogen;
—OCOOR where R is an alkyl group or an aryl groups;
—SO 2 N(R) 2 where R is a hydrogen, an alkyl group, or an aryl group and R and R can form a ring; —OR where R═H, alkyl, aryl, or acyl; for example, R can be an acyl yielding —OCOR* where R* is a hydrogen or an alkyl group or an aryl group and more specifically where R* is methyl, ethyl, propyl, butyl, or phenyl groups all of which groups are optionally substituted;
[0106] Specific substituted alkyl groups include haloalkyl groups, particularly trihalomethyl groups and specifically trifluoromethyl groups. Specific substituted aryl groups include mono-, di-, tri, tetra- and pentahalo-substituted phenyl groups; mono-, di-, tri-, tetra-, penta-, hexa-, and hepta-halo-substituted naphthalene groups; 3- or 4-halo-substituted phenyl groups, 3- or 4-alkyl-substituted phenyl groups, 3- or 4-alkoxy-substituted phenyl groups, 3- or 4-RCO-substituted phenyl, 5- or 6-halo-substituted naphthalene groups. More specifically, substituted aryl groups include acetylphenyl groups, particularly 4-acetylphenyl groups; fluorophenyl groups, particularly 3-fluorophenyl and 4-fluorophenyl groups; chlorophenyl groups, particularly 3-chlorophenyl and 4-chlorophenyl groups; methylphenyl groups, particularly 4-methylphenyl groups, and methoxyphenyl groups, particularly 4-methoxyphenyl groups.
[0107] As to any of the above groups which contain one or more substituents, it is understood, that such groups do not contain any substitution or substitution patterns which are sterically impractical and/or synthetically non-feasible. In addition, the compounds of this invention include all stereochemical isomers arising from the substitution of these compounds.
[0108] Pharmaceutically acceptable salts comprise pharmaceutically-acceptable anions and/or cations. Pharmaceutically-acceptable cations include among others, alkali metal cations (e.g., Li + , Na + , K + ), alkaline earth metal cations (e.g., Ca 2+ , Mg 2+ ), non-toxic heavy metal cations and ammonium (NH 4 + ) and substituted ammonium (N(R′) 4 + , where R′ is hydrogen, alkyl, or substituted alkyl, i.e., including, methyl, ethyl, or hydroxyethyl, specifically, trimethyl ammonium, triethyl ammonium, and triethanol ammonium cations). Pharmaceutically-acceptable anions include among other halides (e.g., Cl − , Br − ), sulfate, acetates (e.g., acetate, trifluoroacetate), ascorbates, aspartates, benzoates, citrates, and lactate.
[0109] Compounds of the invention can have prodrug forms. Prodrugs of the compounds of the invention are useful in the methods of this invention. Any compound that will be converted in vivo to provide a biologically, pharmaceutically or therapeutically active form of a compound of the invention is a prodrug. Various examples and forms of prodrugs are well known in the art. Examples of prodrugs are found, inter alia, in Design of Prodrugs, edited by H. Bundgaard, (Elsevier, 1985), Methods in Enzymology, Vol. 42, at pp. 309-396, edited by K. Widder, et. al. (Academic Press, 1985); A Textbook of Drug Design and Development, edited by Krosgaard-Larsen and H. Bundgaard, Chapter 5, “Design and Application of Prodrugs,” by H. Bundgaard, at pp. 113-191, 1991); H. Bundgaard, Advanced Drug Delivery Reviews, Vol. 8, p. 1-38 (1992); H. Bundgaard, et al., Journal of Pharmaceutical Sciences, Vol. 77, p. 285 (1988); and Nogrady (1985) Medicinal Chemistry A Biochemical Approach, Oxford University Press, New York, pages 388-392).
[0110] The compounds of this invention may contain one or more chiral centers. Accordingly, this invention is intended to include racemic mixtures, diasteromers, enantiomers and mixture enriched in one or more steroisomer. The scope of the invention as described and claimed encompasses the racemic forms of the compounds as well as the individual enantiomers and non-racemic mixtures thereof.
[0111] Before the present methods are described, it is understood that this invention is not limited to the particular methodology, protocols, cell lines, and reagents described, as these may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims.
[0112] It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, reference to “a cell” includes a plurality of such cells and equivalents thereof known to those skilled in the art, and so forth. As well, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably.
[0113] As used herein, the term “treating” includes preventative as well as disorder remittent treatment. As used herein, the terms “reducing”, “suppressing” and “inhibiting” have their commonly understood meaning of lessening or decreasing.
[0114] In certain embodiments, the present invention encompasses administering the compounds useful in the present invention to a patient or subject. A “patient” or “subject”, used equivalently herein, refers to an animal. In particular, an animal refers to a mammal, preferably a human. The subject either: (1) has a condition remediable or treatable by administration of a compound of the invention; or (2) is susceptible to a condition that is preventable by administering a compound of this invention.
[0115] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference for the purpose of describing and disclosing the chemicals, cell lines, vectors, animals, instruments, statistical analysis and methodologies which are reported in the publications which might be used in connection with the invention. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.
[0116] The inventors have a developed an expedient approach to synthesize and screen focused parallel libraries prepared in a macroarray format for antibacterial behavior. Using this format, the inventors have discovered several new antibacterial agents, some of which are comparable to linezolid with respect to antibacterial activity. The inventors have discovered a new structure class for antibacterial compounds that displays excellent activity against S. aureus.
[0117] Cellulose paper is a robust, easy-to-manipulate support for the synthesis of macroarrays of chalcones and chalcone derived heterocycles ( FIG. 2 ). Bowman, M. D.; Jacobson, M. M.; Pujanauski, B. G.; Blackwell, H. E. Tetrahedron 2006, 62, 4715-4727.
[0118] To further expand the utility of this platform, the synthesis of the macroarrays was coupled with high throughput screening techniques. Antimicrobial cationic peptides had been previously prepared by the SPOT-synthesis technique and subsequently screened to find inhibitors at the μg/mL range. Hilpert, K.; Volkmer-Engert, R.; Walter, T.; Hancock, R. E. W. Nature Biotechnology 2005, 23, 1008-1012. Encouraged by this work and previously published accounts of the antibacterial activity of chalcones, the inventors looked at the synthesis and the screening of small molecules by both on-support and solution-based assays. Nielsen, S. F.; Larsen, M.; Boesen, T.; Schonning, K.; Kromann, H. J. Med. Chem. 2005, 48, 2667-2677; Nielsen, S. F; Boesen, T.; Larsen, M.; Schonning, K.; Kromann, H. Biorganic Medicinal Chemistry 2004, 12, 3047-3054; Bowden, K. Dal Pozzo, A.; Duah, C. K. J. Chem. Res . ( S ) 1990, 12, 2801-2830.
[0119] The invention may be further understood by the following non-limiting examples:
Example 1
Synthesis of Libraries Employing Rink Linkers
[0120] FIG. 1 illustrates a general schematic of small molecule macroarray library construction and screening. In order to improve coupling efficiency of the initial building blocks and expand the set of possible building blocks used in library construction, we chose to explore the use of the well-characterized Rink-amide linker system. Bernatowicz, M. S.; Kearney, T.; Neves, R. S.; Koster, H., An Efficient Method for Racemization Free Attachment of 9-Fluorenylmethyloxycarbonyl-Amino Acids to Peptide-Synthesis Supports. Tetrahedron Lett. 1989, 30, 4341-4344; Rink, H., Solid-phase synthesis of protected peptide fragments using a trialkoxy-diphenyl-methyl ester resin. Tetrahedron Lett. 1987, 28, 3787-90. FIG. 2 illustrates the generation of the Rink linker on planar cellulose substrate (e.g., chromatography paper). The figure shows a comparison to the Wang linker used in previous work (WO08/016,738).
[0121] It was reasoned that the use of this system would circumvent some of the problems that are associated with using the Wang linker system to construct small molecule macroarrays. One main advantage of using the Rink linker system is the relatively mild conditions required (standard diisopropylcarbodiimide (DIC) coupling conditions) for coupling the Rink linker to the amino-cellulose support. These conditions are beneficial as they permit the support to stay robust throughout the entire macroarray construction, making it easier to perform syntheses and on-support biological assays post cleavage. Furthermore, we found the Rink linker support to be highly stable, as the support could be prepared and used after sitting on the bench-top for several weeks. This Rink linker strategy also reduces the number of synthetic steps needed to generate a linker suitable for substrate attachment, as an Fmoc-Rink-amide linker can be attached and deprotected in three high-yielding steps. Also, the Rink linker is acid labile, so similar cleavage conditions (TFA vapor) can be used as previously described for the Wang linker system.
[0122] Blackwell et al. has previously had success attaching initial building blocks to Rink linker-derivatized cellulose support using standard peptide coupling reagents. Lin, Q.; O'Neill, J. C.; Blackwell, H. E., Small molecule macroarray construction via Ugi four-component reactions. Org. Lett. 2005, 7, 4455-4458. Using Fmoc-Rink-amide linker and amino-cellulose support, Rink support was prepared with a coupling efficiency of ˜75%. All coupling efficiencies were quantified using standard UV-Fmoc analysis. Carpino, L. A.; Han, G. Y., 9-Fluorenylmethoxycarbonyl Amino-Protecting Group. J. Org. Chem. 1972, 37, 3404. Because of the relative expense of the Fmoc-Rink-amide linker, it was “spotted” (along with coupling reagents) onto the amino-cellulose support, in contrast to the blanket functionalization used with the Wang linker system. Bowman, M. D.; Jacobson, M. M.; Blackwell, H. E., Discovery of fluorescent cyanopyridine and deazalumazine dyes using small molecule macroarrays. Org. Lett. 2006, 8, 1645-1648. We observed a dramatic improvement in the coupling efficiency of the Rink linker compared to previous results with the Wang linker system (75% vs. 15%), especially since the spotting approach employed relied on the use of significantly less linker material.
[0123] In order to attach the acetophenones to the Rink linker, bromoacetic acid (BrAcOH) could be attached using standard DIC coupling conditions, followed by displacement of the bromide by an amino acetophenone. Hydroxyacetophenones however, would still need to be subjected to a KOtBu/DMF solution, in which we found certain hydroxyacetophenones to be insoluble. In order to overcome these solubility problems, the hydroxyacetophenones could first be converted into acetyl-phenoxyacetic acids via S N 2 reaction with methyl bromoacetate and subsequent saponification. These acetyl-phenoxyacetic acids could be directly attached to the Rink-amide linker via a DIC coupling reaction at room temperature to produce support-bound acetophenones, which were then available for further derivatization reactions. Coupling of the acetyl-phenoxyacetic acids to the Rink support proceeded with excellent purity (>95% as determined by HPLC analysis) and modest conversion (60-90% as determined by HPLC analysis). We found that this reaction step could be performed at lower temperatures (43° C.) relative to the Wang linker support (80° C.), which was advantageous as we had observed that multiple reactions at high temperatures “wrinkled” the cellulose support, making it incompatible with on-support biological assays.
[0124] With the acetophenones attached to the Rink linker support, we needed to determine if the same reaction conditions used for the Claisen-Schmidt condensation (benzaldehyde spotted 3× in 1.5 M KOH in 50% EtOH/H 2 O, 80° C., 10 min) would be compatible with the Rink linker system. Before it would be practical to construct larger macroarrays, it was beneficial to optimize the Claisen-Schmidt condensation reaction on the planar array. Initial results from small test libraries had indicated low purities (<60% as determined by HPLC analysis) for the corresponding “Rink” chalcones after TFA cleavage. After several optimization attempts, we found that performing the reaction at a lower temperature (43° C.) resulted in the best reaction conversion and purity of the corresponding Rink support bound chalcones (>85% as determined by HPLC analysis) after TFA cleavage. Again, the low reaction temperatures also helped to preserve the robustness of the cellulose support.
[0125] With the optimized reaction conditions in hand, we proceeded to construct a small molecule macroarray of chalcone derivatives. This library was designed to validate the utility of the Rink system as an improved platform for small molecule macroarray construction, compared to the previous Wang linker system. Acetophenone and benzaldehyde building blocks as shown in FIG. 4 where chosen for preparing a library of chalcones as shown in FIG. 3 . Pyrimidine and pyridine heterocycle derivatives of chalcones were synthesized using previously reported reaction conditions (see FIG. 3 ). Bowman, M. D.; O'Neill, J. C.; Stringer, J. R.; Blackwell, H. E., Rapid Identification of Antibacterial Agents Effective against Staphylococcus aureus Using Small-Molecule Macroarrays. Chem. Biol. 2007, 14, 351-357; see also WO 2008/016738.
[0126] Libraries containing 174 chalcones, 174 cyanopyridines, and 24 pyrimidines were synthesized on a planar cellulose support system ( FIG. 3 ). LC-MS analyses of a subset of the total compounds (20%) cleaved from the macroarray showed good to excellent purities (80-99%).
[0127] FIGS. 5-7 illustrate one advantage of the use of the Rink linker for array synthesis in that it can be used to attach amino acids, peptides, N-substituted glycines or peptoids (oligomers of N-substituted glycines) to the chalcone backbone. FIG. 5 illustrates addition of a N-protected amino acid to the Rink linker followed by reaction with an acetophenone (as described above, exemplary acetophenones listed in FIG. 4 ). Thereafter the benzaldehyde (as described above, exemplary benzaldehydes listed in FIG. 4 ) is reacted with the attached acetophenone to form the chalcone. As illustrated the chalcone derivatized with the amino acid can be released from the substrate. Also as illustrated in FIG. 5 multiple amino acids can be added at point “#” in the synthesis using standard solid-phase peptide synthesis. The R group of the amino acid can in general be any group that does not interfere with the chemistry illustrated in FIG. 5 . As is known in the art certain R groups that might be sensitive or interfere with the chemistry shown may be provided with protective groups. A wide variety of protective groups is known in the art and one of ordinary skill in the art understands how to chose a protective group useful for a given set of reaction conditions.
[0128] FIG. 6 illustrates attachment of an N-substituted glycine to a chalcone backbone. The Rink linker is first reacted as illustrated in FIG. 6 with bromoacetic acid to form a solid attached bromoacetamide which in turn is reacted with a primary amine (most generally NH 2 —R p , see formulas above for exemplary definition of R b ) forming an N-substituted glycine on the solid. The primary amine may be a diamine (as illustrated) a triaminer or a polyamine, in each case the additional amine groups in the R b group must be protected during synthesis). Steps 1 and 2 of FIG. 6 can be repeated to form a peptoid on the solid, e.g.:
[0000]
[0000] The unprotect amine group attached to the solid is then reacted with the acetophenone as described above and thereafter reacted with the benzaldehyde to form the chalcone. FIG. 7 illustrates an alternative peptide synthesis combined with chalcone formation on a solid. In this case an O-protected amino acid (e.g., using OtBu protecting group) is reacted with bromo acetamide on the solid. The unprotected NH of the attached amino acid is then reacted with the acetophenone followed by reaction with the benzaldehyde to form the chalcone. Peptide synthesis can be continued after deprotection of the O-tBu group (other appropriate protecting groups can be used) either before or after chalcone formation. In all of FIGS. 5-7 , the chalcone formed can be further reacted as illustrated in FIG. 3 to form cyanopyridines and pyrimidines.
Example 2
Solution Phase Synthesis of Rink Acetophenones and Rink Chalcones
[0129] As previously discussed, the acetophenones used in macroarray construction required a carboxylic acid functionality for attachment to the Rink amide linker. To efficiently install this moiety, a general synthetic scheme was designed to derivatize a variety of acetophenones (Scheme 1). An acetophenone was reacted with methyl bromo acetate in the presence of potassium carbonate (K 2 CO 3 ), and the product was isolated by precipitation from water. Hydrolysis of the ester with NaOH in H 2 O/THF afforded the acetyl-phenoxyacetic acid carboxylic acid in excellent purity.
[0000]
[0130] In order to estimate the loadings of individual macroarray members, the corresponding acetophenones were cleaved from the macroarray and analyzed by HPLC analysis. An accurate calibration curve was needed for each acetophenone building block to estimate the loading of each macroarray member. Initial attempts at solid phase synthesis of the desired control compounds resulted in low purities and low yields (data not shown), therefore a solution-phase method was pursued.
[0131] An acetophenone was reacted with commercially available 2-bromoacetamide in the presence of K 2 CO 3 , with the product precipitating out after addition of the reaction mixture to water. This solution-phase reaction produced the desired “Rink” acetophenone acid in high yield (70-90%) and excellent purity; allowing for calibration curve generation.
Example 3
Lead Compound Re-Synthesis
[0132] Once active compounds had been identified in the biological assays (as described under Aim 2), they were synthesized in solution to obtain an authentic sample for characterization and further biological evaluation. As some of the active chalcones were similar in structure to our previously reported active chalcones synthesized with the Wang linker 43 , our initial synthetic route was aimed at generating the chalcone first, followed by an S N 2 reaction with 2-bromoacetamide. Although this short synthesis allowed us to obtain the desired chalcone in sufficient quantities after several re-crystallizations, an alternate synthesis was devised to increase reaction yields and decrease purification time.
[0000]
[0133] We found that our solution-phase synthesis of Rink acetophenones could be modified to yield our target chalcones in moderate yields and high purities (Scheme 2). The high purities were attributed to the careful choice of solvent used in the Claisen-Schmidt condensation between the Rink acetophenone and an aldehyde. After dissolving the Rink acetophenone and benzaldehyde in a 1:1 H 2 O:MeOH mixture, 100 uL of a 1:1 (w:v) NaOH:H 2 O solution was added with the chalcone product precipitating out of solution. Purification was thus greatly simplified (no re-crystallization or column chromatography required), as the precipitate was simply filtered and washed several times with a 1:1 H 2 O:MeOH solution to afford the desired Rink chalcone product in excellent purity.
[0134] In order to verify that solution phase synthesis affords only the trans chalcone product, a 1 H NMR spectrum was analyzed by measuring the coupling constants of the two vinylic protons present in the α,β-unsaturated enone moiety. Only one set of vinylic proton peaks were observed and these had coupling constants ranging from 16-17 Hz, indicating a trans double bond. In order to rule out the possibility of the vinylic proton peaks of the cis isomer being obscured or overlapping with other aromatic peaks in the 1 H NMR spectrum, the solution phase Rink chalcones were subjected to LC-MS analysis, which indicated the presence of only 1 peak at 254 nm, thus confirming our initial hypothesis that the trans chalcone is formed when solution phase synthesis is employed.
[0135] It was important to determine which isomers (trans or cis) were produced in the our solution phase Rink chalcone synthesis because it had been previously reported that the trans chalcone isomer is responsible for the antimicrobial activity, while the cis isomer was virtually inactive. Larsen, M.; Kromann, H.; Kharazmi, A.; Nielsen, S. F., Conformationally restricted anti-plasmodial chalcones. Bioorg. Med. Chem. Lett. 2005, 15, 4858-4861.
[0136] Although the double bond of the chalcone is prone to photoisomerization under certain conditions, it is difficult to predict the rate and extent of isomerization for individual chalcones because it is highly dependent on a variety of factors including solvent and type of substitution on aromatic rings. Larsen et al. 2005. The activity results observed for the chalcones may be affected by some level of isomerization of the chalcones.
Example 4
Antibacterial Screening
[0137] After preparation of the small molecule macroarray, we examined several methods for analyzing the antibacterial activity of individual compounds on the macroarray. Our first plan was to analyze each compound using a standard Kirby-Bauer disk diffusion assay. However, this assay gave only a qualitative assessment of antibacterial activity and furthermore, all of the compound was consumed in the assay.
[0138] Next examined was a solution-based assay that consisted of “punching out” individual spots from the macroarray with a standard desktop hole-punch, cleaving the compound in the presence of TFA vapor, and eluting with acetonitrile, and generating stock solutions in DMSO to test antibacterial activity. This procedure allowed for evaluation of antibacterial activity using a minimal amount of compound in a solution-based antibacterial assay, while the remaining compound could be used in HPLC analysis. This allowed direct assessment of the purity of compounds that were used in the solution-based antibacterial assay.
[0139] The third method evaluated was to determine antibacterial activity was an agar-overlay technique (as illustrated in FIG. 8 ), in which a macroarray was cleaved, overlaid with agar inoculated with S. aureus , and incubated for 18 h at 37° C. Macroarrays were cleaved for 1 h in a sealed desiccator saturated with TFA vapor. After the incubation period, triphenyl tetrazolium chloride (TTC) was added to the macroarray, allowing a clear determination of active antibacterial compounds. TTC is a redox indicator commonly used to show the presence or absence of live bacteria. Areas that appeared white indicated dead bacteria (i.e. antibacterial compound), whereas red areas indicated live bacteria (i.e. compound without antibacterial activity).
[0140] One drawback to the agar-overlay technique was that the entire compound was consumed during the assay. Therefore, it was impossible to determine the purities of the compounds that were being screened in the agar-overlay format, which could lead to mis-identification of inactive compounds that merely had low purities. To address this issue it was considered that creating “copies” of the macroarray would allow use of the agar-overlay assay and still have enough of the compound to either test against other bacterial strains or analyze purity by HPLC. A method was used in which the cleaved macroarray could be transferred to multiple cellulose sheets simultaneously. See WO 2008/016738 for more details of this method particularly as applied to macroarrays having Wang linkers. The copies are made by sandwiching a cleaved macroarray between solvent-soaked cellulose sheets and dry cellulose sheets. Pressure is applied, and the solvent is wicked upwards, transferring compound to the previously dry cellulose sheets in a spatially addressed manner. With each new macroarray copy, it is possible to simultaneously screen antibacterial activity of a compound against a number of important human pathogenic bacteria including, methicillin-resistant S. aureus (MRSA), Staphylococcus epidermidis, Bacillus subtilis , and Klebsiella pneumoniae.
[0141] Cleaved macroarrays are neutralized with ammonia vapor before being placed in a suitably sized agar dish. Freshly prepared agar inoculated with bacteria is poured over the entire macroarray, and the array was incubated for 18 h at 37° C. After 18 h, a solution of TTC is added and hits are identified as described above. Agar-overlay assays can also be used to screen antibacterial activity against S. epidermidis, B. subtillis , and K. pneumoniae . Estimated MICs were determined by cleaving the parent acetophenone building block from the macroarray and determining the approximate loading by HPLC analysis.
[0142] Prior to the agar-overlay assay, copies are made of the cleaved macroarray. In order to validate the agar-overlay screen, we use one copy for the agar-overlay method and another copy for a solution-phase MIC assay. In the solution phase assay, individual spots are punched out, placed in separate 4 mL glass vials, and eluted with acetonitrile. After solvent removal, loadings are estimated by analyzing an HPLC trace of the parent macroarray-cleaved acetophenone. Within a given series of acetophenones the corresponding Claisen-Schmidt condensation, as well as the other heterocycle generating reactions, proceeded with nearly 100% conversion. Therefore, we used the amount of cleaved acetophenone from one spot to estimate the amount of chalcone, pyrimidine, or cyanopyridine derivative on other spots. In general, compound amount (post-cleavage) ranged from 100-200 nmoles per spot, which was enough material to perform solution-phase antibacterial assays as well as HPLC or LC-MS analyses.
[0143] Macroarray compounds are dissolved in DMSO and pipetted into a 96-well multititer plate containing Luria-Bertani (LB) broth inoculated with MRSA. The final concentrations of the compounds selected, e.g., 50 μM, 25 μM, 12.5 μM, 6.3 μM, and 3.1 μM, with a final DMSO concentration of 2.5% for each compound in a given well. The plate is incubated with shaking at 37° C. for 18 h, and the absorbance is measured at 595 nm using a plate-reader. The approximate MIC can be determined by the complete absence of bacterial growth relative to our negative control (LB broth with no bacteria added). FIGS. 9A-9O , 10 A- 10 F, 11 A- 11 B and 12 A- 12 B illustrate results of such assays with certain compounds of Formula I.
[0144] It was found that the agar-overlay assay provided a good primary screen for the macroarrays, as the compounds that showed activity in the agar-overlay assay (white spots) also showed good to strong antibacterial activity in the solution-phase assay. The screening methods can be used for a variety of microorganism, including bacteria and fungus. In particular, the screening methods can be employed to assess antibacterial activity against Gram-Negative and Gram-Positive bacteria.
[0145] FIGS. 13A-13E provide exemplary MIC data for several compounds of Formula I.
[0146] Compounds useful for therapeutic application preferably have low hemolytic activity. The hemolytic activity of several compounds of Formula I was assessed using standard methods as illustrated in FIGS. 14A-14C .
[0147] Compounds useful for therapeutic application as antimicrobial activity preferably affect bacterial cell membrane permeability. FIG. 15 illustrates the affect of several compounds of Formula I on the permeability of bacterial cells.
[0000] Support Solution Support MIC MIC Compound Purity (%) a (μM) b (μM) c F19 82 <3.125 3.1 ± 0.2 F17 87 <3.125 3.5 ± 0.5 B19 80 <3.125 4.0 ± 0.5 F5 97 12.5-25 17 ± 1.0 B18 87 25-50 54 ± 1.0 linezolid — — 5.0 ± 1.0 ciprofloxacin — — 0.6 ± 0.2
Table 1. Antibacterial activity of lead compounds from Rink support. (a) determined by HPLC trace at 254 nm. (b) solution-phase assay from cleaved macroarray. (c) authentic solution-phase sample.
[0148] Chalcones B19, F17, and F19 had antibacterial activity with MICs of 4.0±0.5 μM, 3.5±0.5 μM, and 3.1±0.2 μM, respectively (Table 1). (Note that compound names are based on the letter and number code of FIG. 4 which identifies the acetophenone and benzaldehyde used to form the base chalcone.) Several active chalcones, (B19, F17, F19, F5 and B18), were synthesized in solution to obtain more precise MIC values using our previously described solution phase assay. Notably, we identified chalcones that have antibacterial activities against MRSA in the low micromolar range and comparable to commercial therapeutics (ciprofloxican and linezolid).
[0149] In particular Compounds F19, F17 and B19 exhibited low solution MIC's (5 microliter or less) against MRSA and also exhibited low levels of hemolysis at 4× their MIC.
Materials and Methods
Bacteriological Assays
[0150] Bacteriological work was performed with strains obtained from ATCC. Luria-Bertani (LB) medium was used, as directed, for all bacterial work and was solidified with agar as needed. Overnight cultures were grown at 37° C. with shaking ( B. subtilis was grown at 30° C.).
Disk Diffusion Assay
[0151] Compound spots were cleaved with TFA and neutralized with NH 3 as described herein. A 200-μL portion of diluted S. aureus 10390 (10 6 CFU/mL) was spread homogeneously across an agar plate. Compound spots were placed onto the agar, the plate was incubated at 37° C. for 18 h, and the diameters of the zones of inhibition were measured.
Agar Overlay TTC Assay
[0152] Macroarray copies were generated using the array transfer protocol described herein. Warm agar (15 mL) containing 10 6 CFU/mL bacteria was poured into a Petri dish (9 cm diameter). The dish was swirled to eliminate air bubbles, and a macroarray copy (6×6 cm) was fully submerged in the agar. Following an 18 h incubation at 37° C., the plates were flooded with 0.1% (w/v) TTC in LB and allowed to develop for 1 h to visualize the zones of inhibition. Red zones indicated healthy bacteria, while white zones indicated that a compound on the macroarray inhibits growth of the bacterial strain.
MIC Determination
[0153] For estimated MIC determination, DMSO was added to the dried compound residue obtained from a single spot to afford ca. 100 μL of a 2 mM stock solution. Aliquots (5 μL) of these solutions were added to a 96-well plate, followed by 195 μL of diluted S. aureus 10390 (10 6 CFUs/mL) to yield ca. 50 μM final concentrations. The plates were swirled for 1 h to ensure compound dissolution, incubated for 12 h at 37° C., and the absorbance at 595 nm was recorded using a plate reader. Compounds that showed a selected level of growth inhibition at ca. 50 μM were subjected to further testing at C1-C3 concentrations (ca. 25 and 12.5 μM). Actual MIC values were determined for lead compounds resynthesized in solution using an analogous procedure with solutions of known concentration.
Analytical and Synthetic Instrumentation.
[0154] 1 H NMR and 13 C NMR spectra were recorded on a Bruker AC-300 spectrometer in deuterated solvents at 300 MHz and 75 MHz, respectively. Chemical shifts are reported in parts per million (ppm, δ) using tetramethyl silane (TMS) as a reference (0.0 ppm). Couplings are reported in hertz. LC-MS analyses were performed using a Shimadzu LCMS-2010a (Columbia, Md.) equipped with two pumps (LC-10ADvp), controller (SCL-10Avp), autoinjector (SIL-10Advp), UV diode array detector (SPD-M10Avp), and single quadrupole analyzer (by electrospray ionization, ESI). The LC-MS is interfaced with a PC running the Shimadzu LCSolutions software package (Version 2.04 Su2-H2). A Supelco (Bellefonte, Pa.) 15 cm×2.1 mm C-18 wide-pore reverse-phase column was used for all LC-MS work. Standard reverse-phase HPLC conditions for LC-MS analyses were as follows: flow rate=200 μL/min; mobile phase A=0.4% formic acid in H 2 O; mobile phase B=0.2% formic acid in acetonitrile. HPLC analyses were performed using a Shimadzu HPLC equipped with a single pump (LC-10Atvp), solvent mixer (FCV-10Alvp), controller (SCL-10Avp), autoinjector (SIL-10AF), and UV diode array detector (SPD-M10Avp). A Shimadzu Premier 25 cm×4.6 mm C-18 reverse-phase column was used for all HPLC work. Standard reverse-phase HPLC conditions were as follows: flow rate=1.0 mL/min; mobile phase A=0.1% trifluoroacetic acid (TFA) in water; mobile phase B=0.1% TFA in acetonitrile. UV detection at 254 nm was used for all HPLC analyses. Compound purities were determined by integration of the peaks in HPLC traces measured at this wavelength.
[0155] Attenuated total reflectance (ATR)-IR spectra were recorded with a Bruker Tensor 27 spectrometer, outfitted with a single reflection MIRacle Horizontal ATR by Pike Technologies. A ZnSe crystal with spectral range 20,000 to 650 cm −1 was used. UV spectra were recorded using a Cary 50 Scan UV-Vis spectrometer running Cary WinUV 3.00 software. Thin layer chromatography (TLC) was performed on silica gel 60 F 254 plates (E-5715-7, Merck). Sonication of reactions was performed in a laboratory ultrasound bath (Branson model #1510R-MT). All reported melting points are uncorrected.
[0156] Macroarray reactions subjected to oven heating were performed on a pre-heated bed of sand in a standard drying oven (VWR model #13OOU). Temperature measurements of planar surfaces were acquired using a non-contact IR thermometer (Craftsman model #82327) with an error of ±2.5%. An Eppendorf pipetteman with a calibrated range between 0.5 μL and 10.0 μL was used to “spot” or apply reagents onto planar membranes in a spatially addressed manner using disposable plastic tips. Washing steps were 5 min each. After each washing sequence, the macroarray was dried under a stream of N 2 for 20 min.
[0157] Solution-phase, microwave-assisted reactions were performed in a Milestone MicroSYNTH Labstation multimode microwave (MW) synthesis reactor. i This instrument is equipped with a continuous power source (1000 W max) and interfaced with an Ethos MicroSYNTH Lab Terminal PC running EasyWave reaction monitoring software. Using this reactor system, MW irradiation can be applied to reactions using either power (wattage) control or temperature control. Specialized, 70 mL Teflon/polyetheretherketone (PEEK) vessels, designed to withstand temperatures up to 200° C. and pressures up to 280 psi, were used for all MW-assisted reactions. The internal temperature of the reaction vessel was monitored using a fiber-optic temperature sensor enclosed in a protective ceramic sheath. At pressures above the 280-psi limit, the vessels are designed to release excess pressure by venting and then resealing themselves. No evidence of venting was observed during the course of the reactions described herein.
[0158] All chemical reagents were purchased from commercial sources (Alfa-Aesar, Aldrich, and Acros) and used without further purification. Solvents were purchased from commercial sources (Aldrich and J. T. Baker) and used as obtained, with the exception of dichloromethane (CH 2 Cl 2 ), which was distilled over calcium hydride immediately prior to use. Planar cellulose membranes (Whatman 1Chr and 3MM chromatography paper, 20×20 cm squares) were purchased from Fisher Scientific and stored in a dessicator at room temperature until ready for use. All reaction on planar supports were performed under air.
[0159] TFA vapor compound cleavage procedure. Cleavage was performed either on compound spots (for the Kirby-Bauer disk diffusion assay and the solution-phase MIC assay) or the intact macroarray (for the TTC agar overlay assay). Compound spots were punched out of macroarrays using a standard desktop hole punch (spot diameter=6 mm) and placed in individual 4 mL vials. A 10 mL portion of TFA was added to the bottom of a glass vacuum dessicator (interior diameter 21 cm, interior height 20 cm). Up to 240 vials containing the spots (or one 12 cm×18 cm, intact macroarray) were placed on a perforated ceramic platform in the dessicator that was situated 7 cm above the TFA. The dessicator was evacuated to 60 mm Hg over a 10 min period. The dessicator was disconnected from the vacuum, sealed, and allowed to stand for an additional 50 min at room temperature. The vials (or intact macroarray) were removed from the dessicator and allowed to vent in a fume hood for 15 min. For routine LC-MS characterization or the solution-phase MIC assays, the compounds were eluted from the spots by adding acetonitrile (1.0 mL) to each vial. The vials were sealed and shaken for 15 min, after which the paper disks were removed, and the acetonitrile was evaporated under reduced pressure. For the Kirby-Bauer disk diffusion assay or the TTC agar overlay assay, the cleaved spots or macroarrays were subjected to an ammonia (NH3) neutralization step instead of elution (see biological assay section below). This cleavage method gave quantitative release of products (as determined by quantification of cleaved hydroxyacetophenone).
Full Bacteriological Assay Protocols
Kirby-Bauer Disk Diffusion Assay.
[0160] Preparation of Spots. Compound Spots were Subjected to the TFA cleavage conditions described above. The spots were next subjected to NH3 vapor to neutralize any remaining TFA. A 100 mL portion of concentrated NH4OH solution was poured into a 2.6 L Pyrex dish. Vials containing the spots (or intact macroarrays) were placed inside a small evaporating dish, and this was placed into the NH4OH solution. The Pyrex dish was covered, and NH3 vapor was allowed to slowly diffuse into the vials. After 1 h, the vials were removed from the NH3 chamber, and the spots were allowed to stand open in a fume hood for at least 15 min to vent prior to analysis in the following assays. This afforded dry, paper disks containing adsorbed compound. Vancomycin susceptibility test disks (30 μg per disk) and methicillin susceptibility disks (10 μg per disk) were used as controls as received.
[0161] Representative assay procedure. A 400 μL portion of S. aureus overnight culture was diluted with 100 mL of sterile LB broth to give ca. 1.0×106 colony forming units (CFUs) per mL. A 200 μL portion of this suspension was added to Petri dishes containing non-selective agar, and spread homogeneously across the agar with a sterile cotton swab.
[0162] Up to four compound disks (prepared as described above) were placed gently onto the bed of agar equidistant from each other. (Note: either face of the disk could be placed on top of the agar, as the compound was distributed uniformly throughout the disk.) The Petri dishes were incubated at 37° C. for 18 h. The plates were removed, and the diameters of the zones of inhibition were measured in mm using a ruler.
Macroarray Transfer Protocol.
[0163] A chalcone macroarray (12 cm×18 cm) was subjected to the TFA cleavage and NH 3 neutralization conditions described above, except that the spots were not punched out of the array. The intact, cleaved, and dried macroarray was cut into six square sections (12 spots each), and a concentrated fluorescent dye solutions in EtOAc was spotted (ca. 10 nL, using a glass capillary) in-between the compounds for later verification of macroarray transfer.
[0164] Untreated Whatman 3MM filter paper was cut into 6 cm×6 cm squares and arranged into a 2 cm high stack (30 squares). This stack was placed into a glass Petri dish (diameter=15 cm) containing 50 mL EtOH and allowed to soak up the solvent until saturated. A macroarray section was placed facedown on the stack, followed by four additional dry squares of Whatman 3MM. A flat aluminum block was placed on top of the stack and pressure (3 kg) was applied for 90 sec. The four sheets were then removed from the stack, separated with tweezers, allowed to dry, and visualized with a UV lamp (Centela Mineralight Lamp UVGL-58 at 366 nm) to confirm compound transfer. The fluorescent spots were marked with a #2 lead pencil and connected to form a grid. These macroarray copies were subjected to the TTC assay described in detail below. To prevent contamination in subsequent copies, the top two soaked sheets of the filter paper stack were removed after each transfer and replaced with fresh squares of EtOH-soaked filter paper.
[0165] This method gave a gradient of compound concentrations, with the last copy containing the most compound. The gradient was consistent across all locations on the array and for all compounds in the same structure class. Other solvents (CH 2 Cl 2 , MeOH) and longer transfer times were examined; the methods described here were found to be optimal.
Agar Overlay TTC Screening Protocol.
[0166] Test tubes were filled with 15 mL of 0.8% (w/v) agar in LB, autoclaved, and stored in a 55° C. water bath until needed. For bacterial overlay, an appropriate volume of overnight culture was added to each test tube. The tube was gently vortexed, and the contents (15 mL) were quickly poured into a sterile, polystyrene Petri dish (diameter=9 cm). The dish was swirled to eliminate lingering air bubbles, and a 12-spot macroarray copy (described above) was gently slid into the solution. The dish was swirled to completely immerse the membrane in agar, and the agar was allowed to cool. The dish was incubated for 18 h at 37° C. Following incubation, the plates were “flooded” by the addition of 8 mL of 0.1% (w/v) TTC solution in LB and allowed to develop for ca. 1 h to visualize the zones of inhibition. Red zones above the macroarray copy indicated healthy cells, while white zones indicated that a compound on the macroarray copy had growth inhibitory activity against the strain of interest.
[0167] Initially, we performed our overlays according to the procedures published by Silen et al (Silen, J. L.; Lu, A. T.; Solas, D. W.; Gore, M. A.; Maclean, D.; Shah, N. H.; Coffin, J. M.; Bhinderwala, N. S.; Wang, Y.; Tsutsui, K. T.; Look, G. C.; Campbell D. A.; Hale, R. L.; Navre, M.; DeLuca-Flaherty, C. R. Antimicrob. Agents Chem. 1998, 42, 1447-1453.) However, we found that all of the compounds “hit” using this method, and we were unable to determine our best hits. To better resolve the relative activities of our compounds, the agar volume was increased from eight to 15 mL .
[0168] Methicillin susceptibility test. We examined the susceptibility of our two S. aureus strains to methicillin using the agar overlay TTC assay. A susceptibility disk containing 10 μg of methicillin was placed in a Petri dish. Warm agar (0.8% in 15 mL LB) containing 106 CFU/mL of either S. aureus 10390 (SA) or methicillin-resistant S. aureus 33591 (MRSA) was poured over the disk. The dishes were incubated at 37° C. for 18 h and visualized with TTC.
Macroarray Overlay Data.
Estimated MIC Determination Protocol for Macroarray Compounds.
[0169] Preparation of spot samples and controls. An aliquot of DMSO (ca. 100 μL depending on the loading of the parent hydroxyacetophenone) was added to the dried compound residue obtained after TFA cleavage and elution from a single spot. This afforded a 2.0 mM “spot stock” solution for each spot. A small aliquot of each “spot stock” solution was saved for subsequent LC-MS analysis.
[0170] For the linezolid standard, 1.0 mL of acetonitrile was added to a single linezolid susceptibility test disk (30 μg per disk) in a 4 mL vial and vortexed for 15 min. The disk was removed, and the solution was concentrated under reduced pressure. The resulting residue was dissolved in 44 μL of DMSO to afford a 2.0 mM “spot stock” solution of linezolid.
[0171] Control “support” spots were punched from planar supports that had undergone all macroarray synthesis steps except for the loading of the initial hydroxyacetophenone building blocks. These samples allowed us to study the effects of the support background composition on bacterial growth. In addition, hydroxyacetophenone derived spots that had undergone all macroarray synthesis steps except for the Claisen-Schmidt condensation were used as “parent” controls. These samples allowed us to determine the effects of minor impurities resulting from unreacted acetophenone reacting in subsequent steps. “Spot stock” solutions were generated from each of these spots as described above. In all cases studied, neither the support nor the parent control spots affected S. aureus growth.
[0172] For estimated MIC screens, 5.0 μL portions of the “spot stock” solutions were added to the appropriate wells in a sterile, polystyrene 96-well plate to yield ca. 50 μM solutions (dependent on the initial loading of hydroxyacetopheneone and compound purity). To the positive and negative control wells, 5.0 μL of DMSO were added (positive controls contained bacteria but no compound, while negative controls had neither compound, nor bacteria). All estimated MIC assays were performed in quadruplicate. Note: the MIC value is defined as the lowest concentration where no bacterial growth occurs.
[0173] Representative estimated MIC assay procedure. This assay procedure is based in part on the method reported by Strøm et al. (Strøm, M. B.; Haug, E. B.; Skar, M. L.; Stensen, W.; Stiberg, T.; Svendsen, J. S. J. Med. Chem. 2003, 46, 1567-1570.) A 400 μL portion of overnight S. aureus 10390 culture was diluted with 100 mL of sterile LB broth to give ca. 10 6 CFUs per mL. Aliquots (195 μL) of this solution were added to all of the wells in a sterile 96-well plate (except for the negative control wells; 195 μL of sterile LB broth were added to these wells). The plates were placed on an orbital shaker table and gently swirled for 1 h to ensure compound dissolution, and then incubated (without shaking) for 12 h at 37° C. The absorbance at 595 nm was recorded using a plate reader. Compounds that demonstrated complete growth inhibition had an absorbance equal to that of the negative control. Compounds exhibiting no growth inhibition had an absorbance equal to that of the positive control.
[0174] Compounds that showed a selected complete growth inhibition at ca. 50 μM were subjected to further testing. The original “spot stock” solutions of these compounds were diluted with DMSO to give ca. 25 and 13 μM final concentrations and tested for inhibitory activities using the procedure described above.
[0175] All references throughout this application, for example patent documents including issued or granted patents or equivalents; patent application publications; and non-patent literature documents or other source material; are hereby incorporated by reference herein in their entireties, as though individually incorporated by reference, to the extent each reference is at least partially not inconsistent with the disclosure in this application (for example, a reference that is partially inconsistent is incorporated by reference except for the partially inconsistent portion of the reference).
[0176] When a group of substituents is disclosed herein, it is understood that all individual members of those groups and all subgroups, including any isomers and enantiomers of the group members, and classes of compounds that can be formed using the substituents are disclosed separately. When a Markush group or other grouping is used herein, all individual members of the group and all combinations and subcombinations possible of the group are intended to be individually included in the disclosure. When a compound is described herein such that a particular isomer or enantiomer of the compound is not specified, for example, in a formula or in a chemical name, that description is intended to include each isomer and enantiomer of the compound described individually or in any combination. When an atom is described herein, including in a composition, any isotope of such atom is intended to be included. Specific names of compounds are intended to be exemplary, as it is known that one of ordinary skill in the art can name the same compounds differently. Every formulation or combination of components described or exemplified herein can be used to practice the invention, unless otherwise stated. Whenever a range is given in the specification, for example, a temperature range, a time range, or a composition range, all intermediate ranges and subranges, as well as all individual values included in the ranges given are intended to be included in the disclosure.
[0177] All patents and publications mentioned in the specification are indicative of the levels of skill of those skilled in the art to which the invention pertains. References cited herein are incorporated by reference herein in their entirety to indicate the state of the art, in some cases as of their filing date, and it is intended that this information can be employed herein, if needed, to exclude (for example, to disclaim) specific embodiments that are in the prior art. For example, when a compound is claimed, it should be understood that compounds known in the prior art, including certain compounds disclosed in the references disclosed herein (particularly in referenced patent documents), are not intended to be included in the claim.
[0178] The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention. It will be apparent to one of ordinary skill in the art that methods, devices, device elements, materials, procedures and techniques other than those specifically described herein can be applied to the practice of the invention as broadly disclosed herein without resort to undue experimentation. All art-known functional equivalents of methods, devices, device elements, materials, procedures and techniques described herein are intended to be encompassed by this invention. Whenever a range is disclosed, all subranges and individual values are intended to be encompassed. This invention is not to be limited by the embodiments disclosed, including any shown in the drawings or exemplified in the specification, which are given by way of example or illustration and not of limitation.
[0179] The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments, exemplary embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims. The specific embodiments provided herein are examples of useful embodiments of the present invention and it will be apparent to one skilled in the art that the present invention may be carried out using a large number of variations of the devices, device components, methods steps set forth in the present description. As will be obvious to one of skill in the art, methods and devices useful for the present methods can include a large number of optional composition and processing elements and steps.
[0180] Many of the molecules disclosed herein contain one or more ionizable groups [groups from which a proton can be removed (e.g., —COOH) or added (e.g., amines) or which can be quaternized (e.g., amines)]. All possible ionic forms of such molecules and salts thereof are intended to be included individually in the disclosure herein. With regard to salts of the compounds herein, one of ordinary skill in the art can select from among a wide variety of available counterions those that are appropriate for preparation of salts of this invention for a given application. In specific applications, the selection of a given anion or cation for preparation of a salt may result in increased or decreased solubility of that salt.
[0181] Every formulation or combination of components described or exemplified herein can be used to practice the invention, unless otherwise stated.
[0182] Whenever a range is given in the specification, for example, a temperature range, a time range, or a composition or concentration range, all intermediate ranges and subranges, as well as all individual values included in the ranges given are intended to be included in the disclosure. It will be understood that any subranges or individual values in a range or subrange that are included in the description herein can be excluded from the claims herein.
[0183] All patents and publications mentioned in the specification are indicative of the levels of skill of those skilled in the art to which the invention pertains. References cited herein are incorporated by reference herein in their entirety to indicate the state of the art as of their publication or filing date and it is intended that this information can be employed herein, if needed, to exclude specific embodiments that are in the prior art. For example, when composition of matter are claimed, it should be understood that compounds known and available in the art prior to Applicant's invention, including compounds for which an enabling disclosure is provided in the references cited herein, are not intended to be included in the composition of matter claims herein.
[0184] As used herein, “comprising” is synonymous with “including,” “containing,” or “characterized by,” and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. As used herein, “consisting of” excludes any element, step, or ingredient not specified in the claim element. As used herein, “consisting essentially of” does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim. In each instance herein any of the terms “comprising”, “consisting essentially of” and “consisting of” may be replaced with either of the other terms. The invention illustratively described herein suitably may be practiced in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein.
[0185] One of ordinary skill in the art will appreciate that starting materials, biological materials, reagents, synthetic methods, purification methods, analytical methods, assay methods, and biological methods other than those specifically exemplified can be employed in the practice of the invention without resort to undue experimentation. All art-known functional equivalents, of any such materials and methods are intended to be included in this invention. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention that in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.
[0186] Methods of this invention comprise the step of administering a “therapeutically effective amount” of the present therapeutic formulations containing the present compounds, to treat, reduce or regulate a disease state in a patient, including a disease state involving one or more infectious agents such as bacteria. The term “therapeutically effective amount,” as used herein, refers to the amount of the therapeutic formulation, that, when administered to the individual is effective to treat, reduce or regulate a disease state in a patient, including a disease state involving one or more infectious agents such as bacteria. As is understood in the art, the therapeutically effective amount of a given compound or formulation will depend at least in part upon, the mode of administration (e.g. intravenous, oral, topical administration), any carrier or vehicle employed, and the specific individual to whom the formulation is to be administered (age, weight, condition, sex, etc.). The dosage requirements need to achieve the “therapeutically effective amount” vary with the particular formulations employed, the route of administration, and clinical objectives. Based on the results obtained in standard pharmacological test procedures, projected daily dosages of active compound can be determined as is understood in the art.
[0187] Any suitable form of administration can be employed in connection with the therapeutic formulations of the present invention. The therapeutic formulations of this invention can be administered intravenously, in oral dosage forms, intraperitoneally, subcutaneously, or intramuscularly, all using dosage forms well known to those of ordinary skill in the pharmaceutical arts.
[0188] The therapeutic formulations of this invention can be administered alone, but may be administered with a pharmaceutical carrier selected upon the basis of the chosen route of administration and standard pharmaceutical practice.
[0189] The therapeutic formulations of this invention and medicaments of this invention may further comprise one or more pharmaceutically acceptable carrier, excipient, or diluent. Such compositions and medicaments are prepared in accordance with acceptable pharmaceutical procedures, such as, for example, those described in Remingtons Pharmaceutical Sciences, 17th edition, ed. Alfonoso R. Gennaro, Mack Publishing Company, Easton, Pa. (1985), which is incorporated herein by reference in its entirety. | The present invention relates generally to compounds providing antibacterial therapeutic agents and preparations, and related methods of using and making antibacterial compounds. Antibacterial compounds of the present invention include chalcone, alkylpyrimidine, aminopyrimidine and cyanopyridine compounds and derivatives thereof exhibiting minimum inhibitory concentrations (MIC) similar to or less than conventional antibacterial compounds in wide use. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent Application No. 10 2005 006 601.1, filed Feb. 11, 2005, the entire content of which is incorporated herein by reference. The disclosures of all U.S. and foreign patents and patent applications mentioned below are also incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method for transportation of pulverulent filling material through a line, and in particular, micronized filling material. The invention also relates to a device for carrying out the method.
[0003] Pulverulent filling materials may be foodstuffs and luxury items, such as, for example, coffee powder, cocoa powder, and the like. Alternatively, the filling material may be a pharmaceutical, in which case the filling material may contain very small nonflowable pulverized particles, or consist solely of such. In particular, powders used as pharmaceuticals are commonly taken by the patient in the form of what is known as “micronized powder” in very small quantities of 2 to 20 mg (milligrams). Such micronized powders commonly have a particle size of between 0.5 micrometers and 5.0 micrometers and below. Such powders can agglomerate to a very great extent, so that, in technical terms, they cannot be transported and introduced into containers in a simple manner.
[0004] German patent document DE 102 47 829 A1 discloses a method and device for the pneumatic conveyance of pulverulent material through a line. The pulverulent material is acted upon alternately by underpressure and overpressure, and is thus alternately sucked into and pressed out of a line section. Action by gas underpressure and gas overpressure requires a filter element. The finer the pulverulent material is, the more quickly such filter elements clog up. In order to maintain the performance and continuity of the powder transport through the line, the overpressure has to be increased continuously in response to the clogging of the filter element. An attempt is made to reduce the degree of contamination of the filter element (and thereby lengthen its useful life) by designing the filter element in such a way that it surrounds, as a hollow cylinder, the section of the line acted upon by the underpressure and overpressure.
[0005] Filling devices, such as the types known from German patent documents DE 202 09 156 U1 and DE 102 26 989 A1, are commonly supplied with such pulverulent filling material through lines of this type. Pulverulent filling material is introduced from the filling devices into individual containers in predetermined metered quantities. An interruption in the operation of such filling devices, such as may occur, for example, during cleaning work on the above-mentioned filter element which is no longer sufficiently gas-permeable, is highly undesirable.
SUMMARY OF THE INVENTION
[0006] It is an object of the invention to provide a method of supplying pulverulent filling material to filling devices of the above-mentioned type that is as reliable as possible, and at the same time, is as economical as possible.
[0007] According to one exemplary embodiment of the present invention, a method of transporting pulverulent filling material through at least one line comprises: opening a chamber-like line region located in the at least one line; introducing the pulverulent filling material into the chamber-like line region; closing the chamber-like line region; and pressing the pulverulent filling material out of the chamber-like line region and at least partially into the at least one line using at least one compressed air pulse.
[0008] Another exemplary embodiment of the present invention relates to an apparatus for transporting pulverulent filling material. The apparatus comprises: a storage vessel including at least one exit; a chamber-like line region constituting a powder chamber located at the at least one exit of the storage vessel; a line connected to the chamber-like line region, through which a portion of the pulverulent filling material present in the chamber-like line region is transported out of the chamber-like line region; a compressed air duct that issues into the chamber-like line region; and a closing device for the chamber-like line region, the closing device adapted to close the chamber-like line region powder tight with respect to the storage vessel.
[0009] One advantage of the present invention is that no gas-permeable filter elements are required in order to transport the pulverulent filling material. More specifically, the transport of the pulverulent filling material through a line can be implemented solely by gas pressure pulses, such as, for example, air pressure pulses. According to an exemplary embodiment, a chamber-like line region is formed in the line through which pulverulent filling material is to be transported. The chamber-like line region can be opened and pulverulent filling material can be introduced into the chamber-like line region. Subsequently, the chamber-like line region can be closed, and then the introduced filling material can be pressed out of the chamber-like line region and at least a little way into the line by means of at least one compressed air pulse. Additional filling material can then be introduced into the then completely or partially emptied chamber-like line region, and pressed out of the chamber-like line region and a little way into the line in a similar manner. This operation can be repeated intermittently, with the result that filling material portions lying at a greater or lesser distance one behind the other in the line are pressed through the line. At the region of issue of the line, the pulverulent filling material falls, for example, into the storage container of the respective metering device present near the filling device.
[0010] The filling of the chamber-like line region may take place from a powder storage vessel. The powder storage vessel may be positioned, for example, with its outlet present in the bottom region in relation to the chamber-like line region in such a way that powder can flow out of the storage vessel and into the chamber-like line region. Subsequently, the chamber-like line region can be closed, and the pulverulent filling material can be pressed out of the line region and into the line by means of one or more compressed air pulses, as described above.
[0011] The filling material present in the storage vessel may be loosened continuously or intermittently, in order to avoid the formation of material bridges within the storage vessel.
[0012] It has proved advantageous to arrange in the storage vessel a scraping element, by means of which pulverulent filling material can be scraped, that is to say pushed, into the chamber-like line region. The scraping element may at the same time be used in order to close the chamber-like line region. Insofar as the continuously or intermittently driven scraper is located in the region of the orifice of the chamber-like Line region, it may serve as a closure for this line region. During the further movement of the scraper, the latter then releases the orifice, so that a following or the same scraper can again push pulverulent filling material into the line region.
[0013] Details relating to the design of the apparatus according to the invention, by means of which the above-described method according to the invention can be carried out, are illustrated in the drawings. It may be advantageous for a plurality of the lines through which pulverulent filling material is transported to end in a single storage vessel. Pulverulent filling material can thereby be transported out of a single storage vessel through a plurality of lines to a plurality of filling devices. The plurality of outlets of the storage vessel may be arranged in the bottom region of the latter and preferably such that the individual orifices of the various lines can be opened and closed successively, or even simultaneously, by means of one scraper moving, for example, rotating, back and forth. The scraper may correspondingly possess a plurality of scraping arms which, on the one hand, push filling material into the individual chamber-like line regions and, on the other hand, close the respective line regions once these have been filled with filling material. As illustrated by way of example in the drawings, this may effectively be made possible in a simple way in technical terms by means of a rotating scraper having a corresponding number of scraping arms.
[0014] An agitating device may be provided in the storage vessel in order to avoid bridge formation by the filling material in the storage vessel. This agitator device may be fixedly connected to the scraper in structural terms, so that, during, for example, a rotating movement of the agitator, the scraper also rotates.
[0015] The gas, such as, for example, the air pressure pulse required for transporting the individual filling material quantities may be set, as desired, in its pulse length and, independently of this, also in its pressure intensity. In the case of the filter element known in the prior art, which is acted upon alternately by underpressure and by overpressure, and in which the pressure pulse is also utilized for cleaning off the filter element, a specific pressure intensity cannot be undershot. In the present case, this restriction is absent because there is no filter element.
[0016] Further refinements and advantages of the invention may be gathered from the features also listed in the claims and from the exemplary embodiment illustrated in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention is described and explained in more detail below with reference to the exemplary embodiments illustrated in the drawings, in which:
[0018] FIG. 1 is a cross-sectional view through a storage vessel according to the invention with open bottom outlets, taken along line 1 - 1 of FIG. 2 ,
[0019] FIG. 2 is a cross-sectional view through the bottom region of the storage vessel of FIG. 1 , taken along line 2 - 2 of FIG. 1 ,
[0020] FIG. 3 is a cross-sectional view similar to that of FIG. 1 , shown with closed bottom outlets,
[0021] FIG. 4 is a cross-sectional view through the bottom region of the storage vessel of FIG. 3 , taken along line 4 - 4 of FIG. 3 ,
[0022] FIG. 5 is a longitudinal cross-section through an exemplary storage vessel according to the present invention, pivoted through 1800 and docked at a powder container,
[0023] FIG. 6 shows the storage vessel of FIG. 5 , which, together with the powder container, is pivoted back upward again through 180°, and which is filled with powder out of the powder container,
[0024] FIG. 7 is a cross-sectional view similar to FIG. 1 , of another exemplary storage vessel according to the present invention, taken along line 7 - 7 of FIG. 8 , and
[0025] FIG. 8 is a cross-sectional view through the bottom region of the storage vessel of FIG. 7 , taken along line 8 - 8 of FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
[0026] Referring to FIG. 1 , pulverulent filling material 12 is present in a storage vessel 10 . The storage vessel 10 can narrow conically downward. In the exemplary embodiment shown, the storage vessel 10 can be closed by means of a cover 14 when it is oriented as shown in FIG. 1 . Alternatively, the cover 14 can be omitted.
[0027] Six lines 18 can be distributed around the circumference of the bottom 16 of the storage vessel 10 . In the exemplary embodiment shown, the lines 18 are arranged in a star-shaped manner. According to an alternative embodiment, more or less than six lines 18 can be arranged on the storage vessel 10 .
[0028] Each of the lines 18 can end in a chamber-like line region 20 below the bottom 16 . This chamber-like line region 20 can include an orifice 22 directed upward toward the storage vessel 10 . The orifice 22 can communicate with an orifice 24 of approximately the same size in the bottom 16 . The pulverulent filling material 12 present in the storage vessel 10 can fall through the orifice 24 of the bottom 16 and through the orifice 22 in the line 18 into the chamber-like line region 20 of the line 18 from the top downward. This applies to each of the lines 18 .
[0029] The chamber-like line region 20 can constitute an upwardly open powder chamber. The filling of the chamber-like line region 20 can take place by means of a scraper 28 . The scraper 28 , in the exemplary embodiment sh own, includes a plurality of scraping arms 30 (see FIG. 2 ) which rotate over the bottom 16 in a plane parallel to the bottom 16 and at a very short distance from the bottom 16 . The scraping arms 30 can push pulverulent filling materials 12 in the direction of rotation 32 (see FIG. 2 ) into the corresponding line region 20 , by means of their longitudinal sides 36 . During the further rotation of the respective scraper 28 in the direction of rotation 32 , the respective scraping arm 30 can close an orifice 24 in the bottom 16 . The orifice 22 in the chamber-like line region 20 is thereby also closed. The scraper 28 can alternatively include only one scraping arm.
[0030] Compressed air can be pressed into the line region 20 from outside through a compressed air duct 40 issuing into the rear bottom region of the chamber-like line region 20 . The filling material 12 present in the line region 20 can thus be pressed out of the chamber-like line region 20 and at least partially into the line 18 . A compressed air pulse is delivered through the compressed air duct 40 only when the scraping arm 30 closes the orifice 24 , that is to say, when the chamber-like line region 20 is closed in the direction toward the supply vessel 10 . The chamber-like line region 20 can comprise a bag-like end of the respective line 18 .
[0031] A shaft 46 can pass through the storage vessel 10 substantially centrally and substantially vertically (when viewed in the orientation shown in FIG. 1 ). The shaft 46 can be driven in the direction of rotation 32 via a motor drive, not illustrated. The shaft 46 can have a hub 48 fixed to it in terms of rotation. As shown in FIG. 1 , the hub 48 can be located in the bottom region of the storage vessel 10 . In the exemplary embodiment shown in FIG. 2 , the six scraping arms 30 project radially from the hub 48 . An agitator 50 can adjoin the top of the hub 48 . The agitator 50 can be fixed to the shaft 46 in terms of rotation. The agitator 50 can include longitudinal bars 54 , which are arranged parallel to the outer wall 52 of the storage vessel 10 . The longitudinal bars 54 can be arranged at a distance from one another. Transverse bars 56 can connect the longitudinal bars 54 to a sleeve-shaped carrying member 58 which can be fixed in terms of rotation to the hub 48 . Diagonal holding bars 60 can also be provided in the upper region. Consequently, the agitator 50 can have a basket-like configuration.
[0032] During rotation of the shaft 46 , the agitator 50 , together with longitudinal bars 54 , transverse bars 56 , and upper holding bars 60 , can move in the direction of rotation 32 , and thereby loosen the pulverulent filling material 12 present inside the storage vessel 10 . At the same time, during this rotational movement of the agitator 50 , the scraping arms 30 can also move jointly in the direction of rotation 32 , causing powder to move into the region of the bottom orifices 24 . To the extent the chamber-like line region 20 present under the respective bottom orifice 24 is empty, this line region 20 is thus re-filled with powder. To the extent that powder is still present in the chamber-like line region (e.g., because the powder has not been emptied out of the line region 20 by means of one more compressed air pulses), the scraping arm 30 sweeps over the orifice 24 without powder being introduced into the line region 20 .
[0033] FIGS. 3 and 4 illustrate the state in which the six scraping arms 30 are all simultaneously aligned above the corresponding six orifices 24 . In this position, the chamber-like line regions 20 can be emptied.
[0034] Once substantially all of the pulverulent filling material 12 has been transported out of the storage vessel 10 through the lines 18 and the storage vessel 10 is consequently empty, the storage vessel 10 can be pivoted through an angle of 180° about an axis 66 , as shown in FIGS. 5 and 6 . In the exemplary embodiment shown, the axis 66 is substantially horizontal, however alternative configurations are possible. Once inverted, the cover 14 of the storage vessel 10 can be removed, or has previously been removed. A powder container 70 which contains pulverulent filling material 12 and from which the upper cover has been removed can then be docked from below onto the storage vessel 10 ( FIG. 5 ). Subsequently, the storage vessel 10 , together with the docked powder container 70 , can be pivoted upward through 180° again. The storage vessel 10 is then again in its position illustrated in FIGS. 1 and 3 . The pulverulent filling material 12 present in the powder container 70 can then fall downward out of the powder container 70 into the storage vessel 10 . As soon as the powder container 70 is empty, it can be removed from the storage vessel 10 and the storage vessel 10 closed again by means of the cover 14 . Alternatively, the powder container 70 could remain on the storage vessel 10 , so that the cover 14 could be dispensed with. During the aforementioned refilling of the storage vessel 10 with pulverulent filling material 12 , substantially no pulverulent filling material 12 is transported away from the storage vessel 10 through the lines 18 . This does not impede the work of the filling device connected to the lines 18 , since the metering devices present near the filling devices have in each case their own small stores for the pulverulent filling material 12 . The lines 18 connected to the storage vessel 10 end in these stores which belong to the prior art and are not illustrated in the drawings.
[0035] The pressure pulses can be controlled in terms of their pulse length and/or their pressure intensity in the chamber-like line regions of the lines 18 , through monitoring of the fill level of the filling material still present in the respective stores. Accordingly, only the chamber-like line regions 20 that are connected to lines 18 issuing into stores that need to be filled with pulverulent filling material are emptied by means of one or more pressure pulses.
[0036] Referring to FIG. 3 , three portions 12 . 3 of pulverulent filling material 12 are illustrated in line 18 located on the right-hand side of the figure. Each of these portions 12 . 3 can correspond to the quantity of pulverulent filling material pressed out of a chamber-like region 20 by means of a compressed air pulse. The pulverulent filling material 12 or the portion 12 . 3 is in each case pressed only a little way into the line 18 and pressed further on. The emptying operation can take place several times in succession, so that portions 12 . 3 are arranged in succession, like beads on a chain, in the line 18 . In each case, the most-recent portion 12 . 3 to enter the line 18 pushes the front portions 12 . 3 through the line 18 . The individual portions 12 . 3 leave the line in succession at its other end, not illustrated in the drawing.
[0037] The storage vessel 10 . 7 illustrated in FIGS. 7 and 8 differs from the storage vessel 10 in its scraper 28 . 7 . The scraper 28 . 7 includes a single scraping arm 30 . 7 . This scraping arm 30 . 7 can have such a large area extending parallel to the bottom 16 that it simultaneously covers a plurality of (e.g., three or four) the orifices 24 in the bottom 16 . In contrast, the previously described scraper 28 of the storage vessel 10 ( FIGS. 1-6 ) can simultaneously cover or uncover all of the orifices 24 . Thus, in the case of scraper 28 . 7 , the orifices 24 closed in each case can remain closed for a longer period of time compared to scraper 28 , for similar speeds of rotation. As a result, compressed air can be conducted through the respective compressed air duct 40 into the chamber-like line region 20 for comparatively longer than is possible in the case of the scraper 28 .
[0038] The invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art, that changes and modifications may be made without departing from the invention in its broader aspects, and the invention, therefore, as defined in the appended claims, is intended to cover all such changes and modifications that fall within the true spirit of the invention. | A method of tranporting pulverulent filling material through at least one line. The method comprises opening a chamber-like line region located in the at least one line, introducing the pulverulent filling material into the chamber-like line region, closing the chamber-like line region, and pressing the pulverulent filling material out of the chamber-like line region and at least partially into the at least one line using at least one compressed air pulse. | 1 |
This application is a continuation of application Ser. No. 737,664, filed 5/24/85, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image processing apparatus suitable for an electronic file, facsimile, reader or digital copier.
2. Description of the Prior Art
In a prior art apparatus which uses a solid-state image pick-up device such as a CCD to read pixel density of an image to reproduce the image, a function of background elimination in which background color of a document (for example, a newspaper) is not reproduced but only characters are sharply reproduced may be equipped to impart intelligency.
The methods for doing so are classified as follows:
1 The background color is sequentially detected and a binarization threshold is set to be higher than the background density.
2 An entire area of the document is read in advance, the background color level is detected from a density histogram and the binarization threshold is set accordingly. In the method 1, it is difficult to follow an abrupt change in the image density and a portion of character information is dropped or the background color is partially reproduced. Thus, it allows real-time processing but accuracy is low.
On the other hand, the latter or pre-scan method 2 allows high accuracy processing because it can correctly detect the background color. However, since the document has to be read twice, a double length of time is required and this method is not suitable to a high speed apparatus. In addition, the apparatus is complex because it must prepare the density histogram of the entire document.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an image processing apparatus which presents a high quality of reproduced image.
It is another object of the present invention to provide an image processing apparatus which performs background elimination function with high accuracy in real time.
It is another object of the present invention to provide an image processing apparatus having an image discrimination function.
It is another object of the present invention to provide an image processing apparatus capable of presenting an excellent reproduced image with a simple construction.
It is still another object of the present invention to provide an image processing apparatus having an image discrimination function for images whose background colors are to be eliminated.
Other objects features and advantages of the present invention will be apparent from the following description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a density curve of a document having a colored background,
FIG. 2 is a circuit diagram of one embodiment of an image processing apparatus of the present invention,
FIG. 3 shows a detail of an image discrimination circuit,
FIG. 4 shows a detail of a MAX detector 3a, a MAX memory 3b, a MIN detector 3d and MIN memory 3e,
FIG. 5 shows pixel densities of a document,
FIG. 6 shows areas of the MAX memory 3b,
FIG. 7 is a sectional view of a reader and a printer, and
FIG. 8 illustrates a second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The binarization processing by a constant threshold is first explained.
FIG. 1 shows a density curve of a document having a colored background, and unit image areas A1 to A7 represent character areas and background areas. For example, A1 represents a uniform colored background such as that of a newspaper, and A2 and A3 represent character areas. A4 to A7 represent a blue copy document (e.g., one made by diazo type copier). A4 and A7 represent colored background and characters are at a boundary of A5 and A6.
If the image is binarized by a slice level SL shown in FIG. 1, the background is determined as black and the characters cannot be identified, in the areas A1 to A3. In the areas A4 to A7, the characters are reproduced but a portion of the background is also reproduced in dots. Thus, a noisy image is reproduced.
In a prior art system, the threshold is set to a slice level SL1 in the areas A1 to A3 and to a slice level SL2 in the areas A4 to A7 to prevent the background from being reproduced. In the present embodiment, noting the fact that the background area is a gray level area having only a small density change variation within it, the image is divided in character areas and gray level areas, and a binarization threshold for the gray level areas is set to be higher (closer to a black level) than that of the character areas so that the background is eliminated in the reproduced image.
The threshold for the gray level areas should be higher than a maximum density of an ordinary colored background document and lower than an ordinary character density. A large character includes a gray level area having a high density and a small density change. Accordingly, if the above determination is done for each 4×4-pixel block, it may be identified as a gray area. Thus, in the present embodiment, the threshold for the gray level areas is set to 40 (where white level is 0 and black level is 63), which value was experimentally derived to prevent line images such as characters from being binarized to white.
The threshold need not be constant in the 4×4-pixel unit area: the area may be dither-processed (gray level G half-tone processing) to have an average of approximately 40. By setting the threshold to 32-47, the character areas can be reproduced and gray levels and the background can be eliminated.
The threshold to binarize the line image such as characters is usually set to a relatively low level in order to prevent drop-out of the characters and to sharply reproduce the characters. If this low level threshold only is used to eliminate the background of the document containing the characters, the background elimination is not perfect, and in some cases the background partially appears black and the characters or the document cannot be sharply reproduced.
In the present embodiment, a relatively low threshold is set for the character areas to sharply reproduce the characters, and a higher threshold is set for the background area to eliminate the background.
FIG. 2 shows a circuit diagram of one embodiment of the image processing apparatus of the present invention. Numeral 1 denotes a solid-state image pick-up device such as a CCD, which reads an image on a document and converts it to a video signal, numeral 2 denotes an A/D converter which converts an analog video signal to a digital signal, and numeral 3 denotes an image tone discrimination circuit which discriminates an image tone (a characteristic or property of an image) for each 4×4-pixel block, as shown in Japanese Patent Application Ser. No. 92074/1983. An output of the image tone discriminator (which is "1" when a character area is discriminated and "0" when a gray level area is discriminated) is supplied to a multiplexer 9 which selects a corresponding binary video signal 1 (to be described later) and sends it to a image reproducer (printer) 11.
On the other hand, comparators 5 and 6 compare the output of the A/D converter 2 with predetermined binarization thersholds and produce an output "1" if the video signal is larger than the threshold to allow dot printing and produce an output "0" if the video signal is not larger than the threshold. The output of the image tone discrimination circuit 3 and the binary video signal are synchronized by shift registers 4A and 4B.
By the arrangement shown in FIG. 2, the image is discriminated and processed for each block on a real time basis.
A fixed threshold of 25 is set to the comparator 5 from a fixed threshold setting circuit 12 in order to binarize the character areas, and a threshold is selectively set to the comparator 6 by a dither circuit 7 or a fixed threshold setting circuit 8 in order to binarize the image in the gray level area. When the dither circuit 7 is selected, 64 or 16-step gray levels are reproduced by the dither circuit in accordance with the document density in the gray level area, and when the fixed threshold setting circuit 8 is selected, the gray level area (background of the document) is eliminated and only the characters are reproduced on a white background. The threshold from the fixed threshold setting circuit 8 is higher than the threshold from the fixed threshold setting circuit 12, as described above.
A switch 10 is an operation key arranged on a console unit. An operator can select the threshold depending on whether the document is a character document or a character/photograph document. For the character document, the fixed threshold setting circuit 8 is selected, and for the character/photograph document, the dither circuit 7 is selected.
The image tone discrimination circuit 3 may utilize a density difference in the unit block or a space frequency, or any other method which allows separation of the character area and the gray level area. The image may be discriminated for each block or for each pixel.
FIG. 3 shows a detail of the image tone discrimination circuit. Numeral 2a denotes a video data signal which has been converted to the digital signal by the A/D converter 2 and is a 6-bit parallel signal, numeral 3a denotes a MAX detector for detecting a maximum pixel density (L max) for each block, and numeral 3b denotes a MAX memory which stores therein an output from the MAX detector. It can store a 6-bit density level information for each of the blocks which are equal in number to one quarter of the number of pixels in one main scan line. An output of the MAX memory 3b is fed back to an input of the MAX detector 3a to allow comparison of L max in the corresponding block of the preceding main scan line with the pixel density of the current main scan line. The output of the MAX memory 3b is also supplied to a subtractor 3g through a latch 3c. Numeral 3d denotes a MIN detector for detecting a minimum pixel density (L min) for each block, and numeral 3e denotes a MIN memory which stores therein an output from the MIN detector 3d. An output of the MIN memory 3e is supplied to a latch 3f and fed back to the input of the MIN detector 3d to allow comparison of L min in the corresponding block of the preceding main scan line with the pixel density of the current main scan line. Subtractor 3g calculates a difference between the output L max of the latch 3c and the output L min of the latch 3f, that is, (L max-L min), and numeral 3h denotes a comparator for comparing the output (L max-L min) of the subtractor 3g with a predetermined image tone discrimination parameter P. The output of the comparator 3h is stored in an image area memory 3i. The image tone discrimination parameter P is supplied from a parameter circuit 26. Numeral 3j denotes a correction circuit for correcting the output of the image area memory 3i. The image tone discrmination circuit 3 comprises those elements.
The operation of the image processing apparatus is now explained. If the reader (CCD 1 and A/D converter 2) main-scans and sub-scans the document to read it in 64 levels, a 6-bit video data is produced for each pixel and the reader produces the video data signal which is a 6-bit parallel signal. The image tone discrimination circuit 3 divides the image into 4×4-pixel blocks, detects L max and L min for each block, calculates (L max-L min) and compares (L max-L min) with the image tone discrimination parameter P to separate the line image areas such as character areas from the gray level areas.
If (L max-L min)≧P, a line image area is discriminated, and if (L max-L min)<P, a gray level area is discriminated. The result is stored in the memory in the image tone discrimination circuit 3. The line image area is represented by "1" and the gray level area is represented by "0".
The binary data is delayed in the shift registers 4A and 4B by a time equal to that needed for processing in the image tone discrimination circuit 3. When the output of the image tone discrimination circuit 3 is "1", the binary data of the shift register 4A is selected by the multiplexer 9, and when the output of the image tone discrimination circuit 3 is "0", the binary data of the shift register 4B is selected. In the video signal thus obtained, either binarized or dither-processed image data appears for each 4-pixel block in the main scan direction. The binary data from the multiplexer 9 is supplied to the printer 11 which can be such as a laser beam printer, which reproduces an image on a record paper.
FIG. 4 shows a detail of the MAX detector 3a, MAX memory 3b, MIN detector 3d and MIN memory 3e. Numerals 3a-1 and 3d-1 denote comparators and numerals 3a-2 and 3d-2 denote flip-flops (F/F). The RAM 3b, comparator 3a-1 and F/F 3a-2 divide the 4-bit serial image density data 2a to 4×4-pixel unit blocks and detect the maximum pixel density L max for each unit block.
The detection of L max is explained with reference to FIGS. 5 and 6. FIG. 5 shows image densities read by the solid-state image pick-up device such as a CCD, converted to a digital signal by the A/D converter 2 and arranged to correspond to the original document. FIG. 6 shows memory areas of the MAX memory as shown in Fig-6(A), the MAX memory 3b has a space to store 4-pixel data of the image read at 16 pixels/mm in the main scan direction from the document having a length of 256 mm in the main scan direction, that is, data corresponding to image areas A0 to A1023.
In FIG. 5, arrows H and V indicate the main scan direction and the sub-scan direction of the document. A0, A1, . . . are unit blocks (image areas each having 4×4=16 pixels).
Let us assume that when the CCD main-scans the (4n+1) th line, the image data 2
3→7→10→10→8→0→
are sequentially supplied to the comparator 3a-1 and the MAX memory 3b in synchronism with a main scan clock CK. The comparator 3a-1 sequentially compares the serially supplied image data with the data stored in the MAX memory 3b, and if the supplied pixel density is higher, the output of the comparator 3a-1 is held in the F/F 3a-2 and the MAX memory 3b is set to a write mode.
When the first data of the (4n+1)th line is supplied to the comparator 3a-1, it is unconditionally written into the MAX memory 3b as an initial value in the image area in which that data is included. In FIG. 5, the density data "3" is the initial value in the image area A0, and the data "8" is the initial value in the image area A1.
In the image area A0 when the next data "7" of the (n+1)th line is supplied to the comparator 3a-1, the initial value "3" stored in the MAX memory 3b is read and both data values are compared. Since 7>3, the content of the MAX memory 3b is changed from "3" to "7".
Similarly, when the next data values "10" is supplied, the content of the MAX memory 3b is again updated, and at the end of the transfer of the four-pixel data contained in the image area A0 of the (4n+1)th line, the maximum data "10" of the four pixels is stored at the address of the memory area of the MAX memory 3b corresponding to the image area A0.
At the end of the scan of the image area A1 on the (4n+1)th line, the maximum data "9" is stored. The above steps are repeated by 1024 times, for example, to all image areas on the (4n+1)th line, and at the end of the steps, 1024 data are stored at the address of the MAX memory 3b as the maximum data L max of the image areas on the (4n+1)th line.
During the scan of the (4n+2)th line, the image data are sequentially compared with the maximum data of the corresponding image areas on the (4n+1)th line. Accordingly, at the end of the processing of the (4n+2)th line, the data value "10" is stored in the area of the MAX memory 3b for the image area A0 as the maximum data, as shown in FIG. 6(c).
Similarly, at the ends of the processing of the (4n+3)th and (4n+4)th line, the data "15" is stored as shown in FIGS. 6(D) and 6(E).
In the processing of the next {4(n+1)+1}th line, the data "15" is read from the MAX memory 3b as the maximum value L max for the image area A0 before the initial value "12" is written into the same address of the MAX memory 3b, and it is supplied to the subtractor 3g through the latch 3c.
The MIN memory 3e, comparator 3d-2 and F/F 3d-1 detect the minimum pixel density L min in the image area in the same manner as the MAX memory 3b, comparator 3a-1 and F/F 3a-2 detect the maximum density L max.
FIG. 7 shows a digital copier to which the present invention is applied. It shows a sectional view of the reader 1a and the printer 11 shown in FIG. 2. The document is placed face-down on a document glass 33 (a mounting refererence is at the left inner side as viewed from the front). The document is pressed against the document glass 33 by a document cover and is illuminated by a fluorescent lamp 32 and a light reflected therefrom is condensed to a CCD 31 through mirrors 35 and 37 and a lens 36. The mirrors 37 and 35 are moved at velocity ratio of 2. The optical unit is moved from left to right at a constant velocity under a PLL control by a DC servo motor. The velocity is 180 mm/sec in a forward run in which the document is illuminated, and 468 mm/sec in a return run.
The printer unit 11 below the reader unit 1a in FIG. 7 is now explained. The bit-serial image signal processed in the circuit shown in FIG. 2 is supplied to a laser scan optical unit 55 of the printer. This unit comprises a semiconductor laser, collimator lens, rotating polygon mirror, F-a lens and correction optical system. The image signal from the reader is applied to the semiconductor laser where it is electro-optically converted to a laser beam, which is collimated by a collimator lens, and the collimated light is directed to the rotating polygon mirror so that the laser beam scans the photoconductor 38. The polygon mirror is rotated at 2,600 r.p.m.
The laser beam from the unit is directed to the photoconductor 38 through the mirror 54. The photoconductor 38 may comprise three layers, a conductive layer, a photoconductor layer and an insulation layer. Process components for forming the image are arranged around the photoconductor 38. Numeral 39 denotes a pre-discharger, numeral 40 denotes a pre-discharge lamp, numeral 41 denotes a primary charger, numeral 42 denotes a secondary charger, numeral 43 denotes an exposure lamp, numeral 44 denotes a developing unit, numeral 47 denotes a paper feed guide, numeral 48 denotes a regist roller, numeral 49 denotes a transfer charger, numeral 50 denotes a separation roller, numeral 51 denotes a convey guide, numeral 52 denotes a fixer and numeral 53 denotes a tray.
The operation of those process components has been well known and hence detailed explanation thereof is omitted.
In the present embodiment, the input image data are binarized by the comparators. Alternatively, they may be binarized by a memory addressed by the input image data. The same is true for the dither processing. The image tone discrimination method is not limited to those shown in FIGS. 4 to 6 but other methods may be used.
Referring to FIG. 8, a second embodiment is explained. The like elements to those shown in FIG. 2 are designated by the like numerals. In the present embodiment, a control signal is applied from a terminal C to the A/D converter 2. The A/D converter 2 switches an A/D conversion range of the video signal in accordance with the control signal. The control signal may be supplied from an operation key (not shown) arranged on a console (not shown). When a document having a light background is to be reproduced, an operator depresses the operation key. As a result, the control signal is produced and the A/D conversion range of the A/D converter 2 is switched so that the digital video signal without the background component is produced. In this manner, the image with the background eliminated is reproduced on a real time basis.
As described above, according to the present invention, the level of the background of the conventional image is experimentally picked to set a fixed threshold used to binarize only the gray level image area (background area) Accordingly, the hardware scale is very small and yet the background processing is sufficiently practical.
When the gray level in the background is to be reproduced, the threshold is dither-processed. Thus, the characters are sharply reproduced and the gray level area is correctly reproduced in accordance with the original document.
The present invention is not limited to the illustrated embodiments but various modifications may be made within the scope of the claim. | Image processing apparatus comprises a first processor for binarizing an input image data with a first threshold level, a second processor for binarizing the input image data with a second threshold level, and a selector for discriminating an image tone of the input image data and selecting one of the first and second processors in accordance with a discrimination result. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates generally to methods and apparatus for perforating, and more specifically relates to methods and apparatus for retaining shaped charges in a perforating gun.
After an oil or gas well is drilled, casing is typically placed in the well to line the side of the wellbore. Before the well is placed on production, the casing and the producing formation are perforated. Ordinarily, perforating guns are lowered into the well until they are adjacent the formation to be produced. The guns are then detonated, perforating the casing and the formation, and the well may be produced.
Typically, the perforating gun includes a plurality of shaped charges mounted at spaced intervals in a charge carrier. The shaped charges are detonated by means of a detonating cord. Typically the charge carrier takes the form of a hollow cylindrical tube retained within a housing. The housing is adapted to be coupled to the tubing string or to a wireline. The charge carrier tube will include apertures, machined or stamped in the side of the carrier tube, to receive the shaped charges.
In the past, the shaped charges have been mounted in the charge carrier by means of various apparatus, including flat retention bands, threaded assemblies, and bolted flanges. Typically, these prior art apparatus have served to both retain the charges in place in the charge carrier and hold the detonating cord in contact with the shaped charges. As a result, when installing the shaped charges in the charge carrier, it has been necessary to simultaneously ensure that the detonating cord is properly aligned in the mounting clip with the shaped charge.
These conventional methods of mounting shaped charges has several disadvantages. First, the methods are very time consuming since such typical conventional mounting apparatus must be separately inserted into the charge holder before the shaped charge is installed. In addition, conventional mounting apparatus typically cannot satisfactorily be attached to either the shaped charges or the charge carrier prior to assembly of the shaped charge in the carrier. These conventional apparatus thus provide extra pieces to assemble at the well site, and may be easily lost or misplaced.
Accordingly, the present invention provides a securing method and apparatus whereby a shaped charge can be easily mounted in the charge holder and operatively secured to the detonating cord; and whereby the securing apparatus may be affixed to the shaped charges prior to mounting of the shaped charges in the perforating gun.
SUMMARY OF THE INVENTION
In one preferred embodiment, the present invention provides a securing method and apparatus for mounting shaped charges in a charge holder and for holding a detonating cord in contact with the shaped charge through use of two novel clip members. In a particularly preferred embodiment, the shaped charge has two circumferential grooves on its outer surface. A band clip is adapted to fit within one of the circumferential grooves. On one periphery, the band clip has a first set of radially outwardly biased tabs adapted to engage the charge carrier at a first group of locations to prevent movement of the shaped charge inwardly. In the opposite periphery, the band clip has a second set of radially outwardly biased tabs to contact the charge carrier at a second group of locations to prevent outward movement of the shaped charge. A wire clip is mountable in the second circumferential groove on the shaped charge. This wire clip is adapted to engage the detonating cord and to retain it in contact with the shaped charge.
In operation of this particularly preferred embodiment, the band clip and the wire clip are mounted on the shaped charge to form a shaped charge assembly. The detonating cord is run through a carrier tube, and the shaped charge assembly is inserted into the holes in the carrier tube; the band clip tabs lock the shaped charge securely in place, and the detonating cord is then be inserted into the wire clip, securing the detonating cord in operative relation with the shaped charge.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a perforating gun and a shaped charge assembly in accordance with the present invention depicted in an exploded perspective view.
FIGS. 2A-B depict an exemplary band clip of the shaped charge assembly of FIG. 1, illustrated from an oblique view in FIG. 2A, and from a plan view in FIG. 2B.
FIGS. 3A-B depict a wire clip in accordance with the present invention with a shaped charge assembly illustrated from an oblique view in FIG. 3A, and from a plan view in FIG. 3B.
FIGS. 4A-B depict an alternate embodiment of a wire clip in accordance with the present invention, illustrated from an oblique view in FIG. 4A and from a top view in FIG. 4B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, therein is depicted an exemplary shaped charge assembly 10 in accordance with the present invention, illustrated in an exploded view relative to a charge carrier tube 12 of a perforating gun 15. Shaped charge assembly 10 includes a shaped charge 14, a band clip 16 and a wire clip 18.
Shaped charge 14 includes a body 21, with a detonating end 20 and a primer end 22 (shown in greater detail in FIG. 3A). Primer end 22 is adapted to contact a detonating cord 24. Primer end may include a "nipple" as depicted herein, or may be of other conformities, such as a conical portion. When detonating cord 24 is actuated, it detonates shaped charge body 21 at primer end 22, resulting in explosion of shaped charge 14 from detonating end 20. When the perforating gun 2, including charge carrier 12 and shaped charge assemblies 10, is suspended from a wireline or tubing string in a well bore adjacent a producing formation, the explosion results in perforation of the casing and producing formation.
Shaped charge body 21 has a first circumferential groove 26 located on its outer periphery, proximate detonating end 20. First groove 26 is adapted to receive band clip 16. First groove 26 will preferably have a width generally proximate that of band clip 16.
Shaped charge body 26 also has a second circumferential groove 28 located around its outer periphery, proximate primer end 22. Second groove 28 is adapted to receive circular portion 29 of wire clip 18.
Charge carrier 12 i preferably a hollow, generally cylindrical tube, which is adapted to be retained within housing 31. Charge carrier 12 has a plurality of apertures 30 machined or stamped in the outer surface and adapted to receive the round shaped charge bodies 21. Apertures 30 may be positioned in any desired configuration in charge carrier 12, such as in a conventional multiple spiral configuration. Because the outer surface of carrier 12 is curved, apertures 30 appear to "wrap around" charge carrier 12. Thus, sides 32 and 34 of aperture 30, arranged parallel to the longitudinal axis of charge carrier 12, are in a different, radially offset, plane relative to sides 36 and 38 of aperture 30, located approximately ninety degrees removed from side 32 and 34. The radial distance between the plane of sides 32 and 34 and the plane of sides 36 and 38 will vary as a function of the diameter of charge carrier 12. The width of band clip 16 will preferably be established approximately equal to the radial offset between these two planes.
Referring now to FIGS. 2A-B, shown therein in greater detail is band clip 16 in accordance with the present invention. Band clip 16 is preferably formed of flat spring steel, formed into a generally circular shape. The ends of band clip 16 are preferably not joined together, but are allowed to overlap, to allow circumferential expansion of band clip 16. Band clip 16 has a first peripheral side 40 and a second peripheral side 42. Locking tabs 44 are formed in first peripheral side 40 of band clip 16. As best seen in FIG. 2a, locking tabs 44 are radially outwardly biased. Locking tabs 44 are spaced so as to be diametrically opposed when band clip 16 is expanded and placed around shaped charge body 21. Locking tabs 44 may be formed by cuts extending partially through the width of band clip 16, with the separated portion bent outwardly from the center of band clip 16. Additional diametrically opposed tabs 46 are formed in second peripheral side 42 of band clip 16. Locking tabs 46 are positioned on band clip 16 spaced approximately 90 degrees apart from locking tabs 44. Tabs 46 are formed from the second side 42 of band clip 16 and again extend radially outward. Preferably, locking tabs 46 include double adjacent tabs at each location (each tab being about 0.375 inches in one preferred embodiment), while tabs 44 are single tabs at each location.
When band clip 16 is mounted on shaped charge body 21, first peripheral side 40 is positioned proximate detonating end 20 of shaped charge body 21. When shaped charge assembly 10 is mounted in carrier 12, locking tabs 44 are aligned with the longitudinal axis of charge carrier 12 and engage sides 32 and 34 of apertures 30. Locking tabs 46 are aligned perpendicular to the longitudinal axis of charge carrier 12 and engage sides 36 and 38 of apertures 30.
As best seen in FIG. 3A, due to the effect of apertures 30 "wrapping around" the outer surface of charge carrier 12, the first side 40 of band clip 16 engages sides 32 and 34 of aperture 30 at the same time that second side 42 of band clip 16 engages sides 36 and 38 of aperture 30. Locking tabs 44 engage charge carrier tube 12 from the inside, while locking tabs 46 engage charge carrier 12 from the outside. Therefore, when shaped charge assembly 10 is mounted in carrier tube 12, locking tabs 44 prevent outward movement of shaped charge assembly 10, while tabs 46 prevent inward movement.
Referring now to FIG. 3B, shown therein in greater detail is an exemplary embodiment of a wire clip 18 in accordance with the present invention. Wire clip 18 includes a generally circular section 48 which is adapted to engage second circumferential groove 28 of charge body 14. Wire clip 18 includes a pair of arms 50 and 52 which extend outwardly from the circular section 48. As shown in FIG. 2, arms 50 and 52 are generally parallel. Arms 50 and 52 are spaced apart a sufficient amount to receive detonating cord 24 between them. As shown in FIG. 3A, when wire clip 18 is mounted on shaped charge body 21, detonating cord 24 may be placed between arms 50 and 52 of wire clip 18 and held in contact with primer end 22 of shaped charge 14.
Referring now to FIGS. 4A-B, depicted therein is an alternate embodiment of wire clip 18' in accordance with the present invention. Wire clip 18' has a generally circular section 48' which is adapted to engage with the second circumferential groove 22 of shaped charge body 21. Arms 50' and 52' extend outwardly from the circular section 48'. Arms 50' and 52' are shaped to form a semicircular channel 54. Channel 54 is adapted to receive detonating cord 24, which is held in contact with the shaped charge under arms 50' and 52' and generally perpendicular to arms 50' and 52'.
The method of installing shaped charges in a charge carrier using a shaped charge assembly 10 will be described primarily in reference to FIG. 1. A detonating cord 24 is placed inside charge carrier 12. Band clip 16 is expanded to fit around shaped charge 21 in first groove 26, and wire clip 18 is installed within second groove 28 in shaped charge body 21, to form shaped charge assembly 10. Shaped charge assembly 10 is inserted into aperture 30 in charge carrier 12. Locking tabs 44 are aligned with the longitudinal axis of carrier tube 12, and the assembly is inserted into aperture 30. When shaped charge assembly 10 is inserted in aperture 30, locking tabs 44 engage sides 32 and 34 of hole 30. As charge assembly 10 is inserted, locking tabs 44 are displaced radially inward. When charge assembly 10 is fully inserted, locking tabs 44 spring radially outward and engage with sides 32 and 34 of aperture 30 to retain shaped charge body 14 in place. In addition, tabs 46 engage with sides 36 and 38 of hole 30 to prevent further inward movement of shaped charge body 14. After shaped charge assembly is mounted in carrier tube 12, detonating cord 24 is inserted between arms 50 and 52 of wire clip 18. Alternatively, detonation cord 24 may be clipped to shaped charge assembly 10, prior to installation of shaped charge assembly 10 in carrier tube 12.
Many modifications and variations may be made in the techniques and structures illustrated herein without departing from the spirit and scope of the present invention. Accordingly, the techniques and structures described herein are illustrative only and are not to be considered as limitations upon the scope of the present invention. | The invention provides a perforating assembly and a method and apparatus for retaining shaped charges in a charge carrier. A shaped charge body has two clips associated with it: a band clip having a plurality of radially extending tabs oppositely oriented for mounting the shaped charge body in the charge carrier, and for securing the shaped charge body in place; and a wire clip mounted on the shaped charge body and adapted to hold a detonating cord in contact with the shaped charge. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to the field of biotechnology, and more particularly, relates to an optimized recombinant flagellin protein and preparation and use thereof.
BACKGROUND OF THE INVENTION
[0002] It is known that flagellin proteins originated from pathogenic bacteria have immune adjuvant effects. The flagellin protein binds to Toll-like receptors (TLRs) 5, activating the NF-κB pathway and then triggering innate immunity and further inducing specific immunity. The mixture or fusion of flagellin protein with a target antigen can significantly enhance the immune responses to the target antigen upon immunization, and can achieve the effects of resisting pathogenic microorganisms carrying the target antigen. But because the flagellin protein originates from pathogenic bacteria, it may have potential risk, and it also can cause inflammatory response, induce a large amount of immune response against itself, lead to possible tolerance and other possible immunological side effects.
SUMMARY OF THE INVENTION
[0003] The present invention provides an optimized recombinant flagellin protein, and uses it as adjuvant; while ensuring the maintenance of its adjuvant activity, the optimized recombinant flagellin protein has decreased antigenicity, immunogenicity and inflammatory response.
[0004] The first aspect of the present invention provides a recombinant flagellin protein with a deletion in the hypervariable region, where the hypervariable region consists of amino acids from 180 to 400.
[0005] Preferably, the recombinant flagellin protein includes FliCΔ190-278, FliCΔ220-320 or FliCΔ180-400.
[0006] The second aspect of the present invention provides a method of preparing recombinant flagellin protein, including making deletions in the hypervariable region of the flagellin protein, where the hypervariable region consists of amino acids from 180 to 400.
[0007] Specifically, the preparation method comprises the following steps:
[0008] (1) construction of the flagellin protein recombinant plasmid;
[0009] (2) construction of the flagellin deletion clones by using the flagellin protein recombinant plasmid obtained from step 1 as template, and expression and purification.
[0010] Preferred, the template of above step (1) construction of the flagellin protein recombinant plasmid is the genome of human Salmonella enterica J341, the primers are the sequences shown in SEQ ID NO: 1 and SEQ ID NO: 2, the ligation vector is the pET28.
[0011] Preferred, the primers of above step (2) construction of the flagellin deletion clones are the sequences shown in SEQ ID NO: 3 to SEQ ID NO: 6, to obtain the recombinant flagellin protein FliCΔ190-278; or the sequences shown in SEQ ID NO: 7 to SEQ ID NO: 10, to obtain the recombinant flagellin protein FliCΔ220-320; or the sequences shown in SEQ ID NO: 11 to SEQ ID NO: 14, to obtain the recombinant flagellin protein FliCΔ180-400. Details are shown in the embodiments.
[0012] The present invention also provides a use of the recombinant flagellin protein as adjuvant. Because the adjuvant was obtained by manipulating the flagellin protein, the antigenicity and immunogenicity and inflammatory response of the recombinant flagellin protein were decreased, while its adjuvant activity is maintained.
[0013] Compared to the prior art, the present invention has the following beneficial effects:
[0014] By manipulating the flagellin protein with deletion of its main immunogenicity and antigenicity regions, its antigenicity and immunogenicity and inflammatory response are decreased.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows the pictures of purification and verification of the expressed flagellin protein by SDS-PAGE and western blot respectively;
[0016] FIG. 2 shows the IL-8 and MCP-1 release level of Caco-2 cells induced by FliC or FliC297-471 stimulation respectively, wherein (A) shows the IL-8 release level of Caco-2 cells induced by FliC or FliC297-471 stimulation respectively, and (B) shows the MCP-1 release level of Caco-2 cells induced by FliC or FliC297-471 stimulation respectively;
[0017] FIG. 3 shows the results of FliC adjuvant activity at different concentrations, wherein (A) shows the p24-specific IgG titers in sera, (B) the p24-specific IgA titers in sera, (C) the p24-specific IgA titers in salivary, (D) the p24-specific IgA titers in vaginal samples, and (E) the p24-specific and FliC-specific IgG titers in sera;
[0018] FIG. 4 shows the expression and purification of recombinant flagellin proteins, wherein (A) shows the structure diagrams of three deletion proteins, (B) the modeled three dimensional structures of FliC and three deletion proteins, (C) the SDS-PAGE electrophoretogram of FliC and three deletion proteins in the insoluble fraction, (D) the SDS PAGE electrophoretogram of FliC and three deletion proteins in the soluble fraction, and (E) the Western blot of FliC and three deletion proteins; where (1), (2), (3) and (4) in (B) to (E) are corresponding to the ones shown in (A);
[0019] FIG. 5 shows the experimental results of FliC-specific and FliC-recombinant protein-specific IgG titers in the sera, wherein (A) shows the FliC-specific IgG titers in the sera of mice immunized with FliC or different FliC-recombinant proteins respectively by ELISA, and (B) the FliC-specific or FliC-recombinant protein-specific IgG titers in the sera by ELISA;
[0020] FIG. 6 shows the ELISA results of IL-8 and MCP-1 quantity in the supernatants of Caco-2 cells stimulated respectively with FliC, FliCΔ190-278, FliCΔ220-320 or FliCΔ180-400 at different concentrations(0.1,1,10,100,1000, 10000 ng/ml), wherein (A) shows the IL-8 levels, and (B) the MCP-1 level;
[0021] FIG. 7 shows the p24-specific antibody titers in sera, saliva, or vaginal samples from BalB/c mice immunized with p24 as antigen (10 μg/mouse) in mixture with FliC, FliCΔ190-278, FliCΔ220-320 or FliCΔ180-400 (2.5 μg/mouse) respectively, wherein (A) shows the p24-specific IgG titers in sera, (B) the p24-specific IgA titers in sera, (C) the p24-specific IgA titers in saliva, and (D) the p24-specific IgA titers in vaginal samples;
[0022] FIG. 8 shows the results of the weight changes after the mice were intranasally immunized, conventional fed after immunization, continuously observed for 7 days, and the weights of mice were daily recorded;
[0023] FIG. 9 shows the gross lesions of the livers from the C57BL/6 mice that were intranasally immunized with FliC1 and killed respectively at 12 th hour, 24 th hour, and a week after immunization, wherein (A) shows the gross appearance of the mouse liver of PBS group, (B1) the gross appearance of the mouse liver of treated group killed at 12 th hour, (B2) the gross appearance of the mouse liver of treated group killed at 24 th hour, and (B3) the gross appearance of the mouse liver of treated group killed at one week;
[0024] FIG. 10 shows the micro-lesions of mouse livers corresponding to the one shown in FIG. 9 , wherein (A) shows the HE staining results of liver tissue of PBS group, (B1) the HE staining results of liver tissue of treated group killed at 12 th hour, (B2) the HE staining results of liver tissue of treated group killed at 24 th hour, and (B3) the HE staining results of liver tissue of treated group killed at one week;
[0025] FIG. 11 shows the biochemical analysis results of biochemical indexes reflecting liver injury, using the sera of the FliC immunized group, wherein (A), (B), (C), (D), (E), (F), (G) and (H) were the biochemical analysis results of ALT, AST, TP, ALB, TBiL, DBiL, BUN and CREA, respectively;
[0026] FIG. 12 shows related experiment results of FliCΔ220-320 safety, wherein (A) shows the comparison results of ALT and AST concentrations in the immunized sera of the FliC or different recombinant protein groups, (B) the gross appearance of the livers from the mice immunized with FliC or different recombinant proteins and killed at 24 hours post-immunization, and (C) the microscopic observations of liver lesions from the corresponding groups of (B).
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention will be further illustrated combining with embodiments as follows. It should be noted that the scope of the present invention is not limited by the embodiments.
[0028] The experimental method without given specific conditions is referred to the conventional conditions, such as the conditions described in Sambrook and other molecular cloning experiments manuals.
Embodiment 1
Construction of Cloning
[0029] (1) Construction of FliC Recombinant Plasmid
[0030] FliC (SEQ ID NO. 17) was obtained by PCR amplification from the genome of human Salmonella enterica J341, using the primer1/primer2 (SEQ ID NOs. 1/2) as primers (primer sequences see Table 1). The NcoI and XhoI restriction sites in the primers are underlined. In order to facilitate purification of recombinant protein, the stop codon TAA of flic gene was deleted when the primer2 was designed, thus making a 6-histidine tag which after the restriction site XhoI of vector pET28 for fusion expression. PCR products were double digested with NcoI and XhoI, and were ligated with vector pET28a which also was double digested and linearized. Ligated products were transformed into BL21 (DE3) star; positive clones were picked for restriction enzyme digestion and sequencing, the correct recombinant plasmid was named FliC, and its expression products had the 6-histidine tag at C-terminal.
[0031] (2) Construction of the Flagellin Deletion Clones of FliCΔ180-400 (SEQ ID NO. 18), FliCΔ190-278 (SEQ ID NO. 19) and FliCΔ220-320 (SEQ ID NO. 20)
[0032] Construction of the FliCΔ180-400: fragment FliC (1-180AA) and FliC (400-560AA) were amplified, by using the FliC1 recombinant plasmid as template, and respectively using the primer21/primer22 (SEQ ID NO. 3/4), primer23/primer24 (SEQ ID NO. 5/6) as the primers (primer sequences see Table 1, Table 1 shows the oligonucleotide primers). The 5 'end of primer21 and primer22 were respectively designed with restriction sites NcoI and EcoRI, the 5 'end of primer23 and primer24 were respectively designed with restriction sites EcoRI and XhoI. After the PCR products were digested with NcoI/EcoRI and EcoRI/XhoI, both the C-terminal of FliC (1-180AA) fragment and the N-terminal of FliC (400-560AA) fragment produced the same EcoRI sticky ends. The restriction digested fragments were placed at 4° C. to ligate for 1 hour according to the ratio of 1:1, and the ligated products were purified by running on gel. The purified products ligated with the vector pET28a which had been double digested and linearized by NcoI and XhoI. Ligated products were transformed into BL21 (DE3) star; positive clones were picked for restriction enzyme digestion and sequencing, the correct recombinant plasmid was named FliCΔ180-400.
[0033] Construction of the FliCΔ190-278 and FliCΔ220-320, PCR amplification was carried out, by using primer13/primer14 (SEQ ID NOs. 7/8) and primer15/primer16 (SEQ ID NOs. 9/10) as well as primer17/primer18 (SEQ ID NOs. 11/12) and primer19/primer20 (SEQ ID NOs. 13/14) as primers (primer sequences see Table 1) respectively. The construction process was the same as that of the recombinant plasmid FliCΔ180-400. FliC297-471 (SEQ ID NO. 21) was constructed using primers 31/32 (SEQ ID NOs. 15/15) following the same protocol as described above.
[0000]
TABLE 1
plasmids
primers
sequences (5′-3′)
FliC1
primer1
CGCG CCATGG CACAAGTCATTAATACA
AACA
(SEQ ID NO. 1)
Primer2
CGGT CTCGAG ACGCAGTAAAGAGAGGA
CGTTTTG
(SEQ ID NO. 2)
FliCΔ190-278
Primer13
CCTACG CCATGG CACAAGTCATTAATA
CA
(SEQ ID NO. 3)
Primer14
GGCAGT GAATTC TTTATCAACGGTTAC
AGCAGT
(SEQ ID NO. 4)
Primer15
CGATGC GAATTC ATAACCCACAACCAA
ATTGCT
(SEQ ID NO. 5)
Primer16
GATCCG CTCGAG ACGCAGTAAAGAGAG
GACGTT
(SEQ ID NO. 6)
FliCΔ220-320
Primer17
CGCGTT CCATGG CACAAGTCATTAATA
CA
(SEQ ID NO. 7)
Primer18
CCAGTA GAATTC AGTAACCCCCGTTGC
ACCACC
(SEQ ID NO. 8)
Primer19
CCAGTG GAATTC TTTGAGGATAAAAAC
GGTAAG
(SEQ ID NO. 9)
Primer20
GCCGAT CTCGAG ACGCAGTAAAGAGAG
GACGTTTTG
(SEQ ID NO. 10)
FliCΔ180-400
Primer21
CGCGTT CCATGG CACAAGTCATTAATA
CA
(SEQ ID NO. 11)
Primer22
GGCTTG GAATTC GGTGTAGGCATCTTG
GACATT
(SEQ ID NO. 12)
Primer23
GGCACG GAATTC AACTTCAGAACAGGC
GGTGAG
(SEQ ID NO. 13)
Primer24
GCCGAT CTCGAG ACGCAGTAAAGAGAG
GACGTTTTG
(SEQ ID NO. 14)
FliC297-471
Primer31
CTCGAT CCATGG TTGCGGCTCAACTTG
CTGCA
(SEQ ID NO. 15)
Primer32
GGCTGA CTCGAG TGCGTAGTCGGAATC
TTCGAT
(SEQ ID NO. 16)
Embodiment 2
Expression and Purification of Recombinant Proteins
[0034] A single colony was picked and the bacteria cells were incubated overnight (37° C., 220 rpm), with kanamycin 50 μg/ml. It was transferred at 1% into fresh 2YT medium (tryptone 16 g/L, yeast extract 10 g/L, NaCl 5 g/L) (37° C., 220 rpm) in the next day, with kanamycin 50 μg/ml. After transferred for 2-3 h (the bacteria grew into early—middle logarithmic growth phase), IPTG was added to induce expression (final concentration was 0.5 mM). After 4-5 h of induced expression, the bacteria cells were centrifuged and collected, resuspended in 20 ml 1×binding buffer (20 mM Tris-HCl, 500 mM NaCl, 5 mM imidazole, pH7.9) per gram of bacteria, the bacteria cells were sonicated, centrifuged (13000 rpm, 20 min, 4° C.). The supernatant was purified with nickel column. The combined recombinant protein was eluted with elution buffer (20 mM Tris-HCl, 500 mM NaCl, 250mM imidazole, pH7.9). The purity and molecular size of the collected recombinant protein was determined by sodium dodecyl sulfate-polyacrylamide polyacrylamide gel electrophoresis (SDS-PAGE).
[0035] In western blot analysis, the purified flagellin protein was transferred onto nitrocellulose membrane through SDS-PAGE, blocked in 1% skim milk powder at room temperature for 2 h, and then the membrane was incubated with mouse anti-his-tag monoclonal antibody (1:2000 dilution), incubated at 4° C. overnight; the membrane was washed with TBST for five times, 10 min per time, and was incubated with HRP-conjugated goat anti-mouse anti-IgG antibody (1:100,000 dilution), at room temperature for 1 h, and then washed with TBST for five times. Detected with chemiluminescence solution (Pierce) for 5 min and observed the result.
[0036] The result is shown in FIG. 1 . FIG. 1 shows the result figures of purified protein verification by SDS-PAGE and western blot respectively. 0.5 mmol/L IPTG was added when the bacteria was incubated to OD600 value of 0.6-1.0 at 37° C. After 4 h of induced expression at 37° C., the bacteria cell was collected, sonicated, and purified with nickel column. The purified protein was verificated by SDS-PAGE and western blot. Shown in FIG. 1 , an approximate 52 KD protein was successfully obtained.
[0037] Removal endotoxin from the recombinant protein and detection, as follows: affinity chromatography: the purified flagellin protein was removed of endotoxin with polymyxin B affinity column (Pierce), and detected residual endotoxin content with lachypleus amebocyte lysate, the residual endotoxin content <0.06 EU/mg.
Embodiment 3
MCP-1 and IL-8 Release Assay
[0038] According to the literature, Caco-2 cells constitutively expressed TLR5, flagellin was the ligand of TLR5, the Caco-2 cells stimulated by flagellin could be induced to release high level of chemokines IL-8 and MCP-1. To research whether the flagellin originated from Salmonella J341 also had stimulating activity, the Caco-2 cells were seeded in 24 well plates, 2'10 5 /well, for 7-21 days to make the cells become polarized. Before stimulation, the cells were kept starving for 8 -12 h, and then the starvation medium was removed when stimulating. The cells were washed twice with fresh serum-free medium. Samples were diluted with serum-free medium at concentration of FliC 0.1,1,10,100,1000 ng/ml respectively. The diluted samples were loaded into each well, 1 ml/well, each treated 4 wells. Negative control cells were stimulated with FliC297-471 and serum-free medium respectively, the culture medium were collected after 6 hours, and centrifuged for 10 min at 2000 rpm. The supernatant was obtained to detect cytokines IL-8 and MCP-1.
[0039] The result is shown in FIG. 2 . FIG. 2 shows the IL-8 and MCP-1 release level of Caco-2 cells induced by FliC stimulation, wherein (A) shows the IL-8 release level of Caco-2 cells induced by FliC stimulation, and (B) shows the MCP-1 release level of Caco-2 cells induced by FliC stimulation. Shown in FIG. 2 , compared with the control, FliC stimulation induced Caco-2 cells to release high level of IL-8 and MCP-1, while they were consistent, low dose (<100 ng/ml) stimulation induced obvious dose effect, and when the dose >1000 ng/ml the stimulating activity reached saturation. Considering the residual endotoxin may interfere with the stimulating activity of flagellin, the control cells were stimulated with FliC297-471 without stimulating activity which had been expressed and purified as same, to confirm the stimulating activity was specific of flagellin. The result showed that there was no difference between the FliC297-471 treated cells and serum-free medium only added cells, thus indicated that the stimulating activity was specific of flagellin.
Embodiment 4
Experiment in Mice for Investigating the Adjuvant Activity of Flagellin Protein
[0040] 6-8 weeks old BALB/c or C57BL/6 mice were purchased from Center For Disease Control of Hubei province, and raised at the animal experiment center of Wuhan Institute of Virology, Chinese Academy of Sciences(CAS). Before immunization, they were fed 3-7 days to adapt to the environment. Intranasal immunization: the mice were anesthetized with 120-150 μl (10 mg/ml) pentobarbital via intraperitoneal injection, the sample was diluted with endotoxin-free PBS. Total volume of intranasal was 10 μl, 5 μl/once, for twice, ensuring the sample to be fully absorbed. Immunization strategy: primary immunization (0 week)—first booster immunization (4th week)—second booster immunization (6th week), decide whether to booster and the booster times according to situation. The mice were killed 2 weeks after the last immunization, their blood and saliva samples, vaginal samples were collected. The mice should be kept fasting (not fasting in liquid) 1 day. Saliva samples: first injected carbachol (200 μg/ml), 100 μl/mouse, observed salivary secretion in mice, 1˜2 min later, the secretion of saliva was absorbed into 1.5 ml EP; vaginal samples: vaginal of mice were lavaged with 90˜100 μl PBS, 30 μl/once, for 3 times; bronchoalveolar lavage fluid (BALF): bronchoalveolar of mice were lavaged with 1 ml PBS, 500 μl/once, for 2 times. Blood samples were incubated at 4° C. for 3˜4 h, and centrifuged for 30 min at 1500 rpm, the supernatant was saved at −80° C. for subsequence detection. Mucosal samples were centrifuged for 10 min at 10000 rpm, the supernatant was saved at −80° C. for subsequence detection.
[0041] To further investigate the adjuvant activity of flagellin protein, HIV core protein p24 10 ug was used as model antigen. 6-8 weeks old BALB/c mice were divided into 5 groups, intranasal immunized with PBS, FliC297-471, FliC 2.5, 5, 10 ug respectively, booster immunized one time after 4 weeks, killed 2 weeks after the last immunization. The serum and mucosal samples were obtained to detect titer of p24-specific and FliC-specific antibody by ELISA. The results are shown in FIG. 3 , FIG. 3 shows the related experimental results of FliC adjuvant activity, wherein (A) shows the comparison results of p24-specific IgG titers in sera, (B) shows the comparison results of p24-specific IgA titers in sera, (C) shows the comparison results of p24-specific IgA titers in salivary, (D) shows the comparison results of IgA titers in vaginal, and (E) shows the comparison results of IgG titers in sera. The results of FIG. 3 show that, compared with PBS and FliC297-471 control groups, FliC immunized group significantly enhanced the titers of p24-specific IgG, IgA in sera and IgA in mucosal samples ( FIG. 3 , A, B, C and D), indicating that FliC had strong adjuvant activity. Surprisingly, we found that when FliC was 10 μg, the titer of p24-specific serum IgG and IgA was lower than that of low dose of 2.5 μg and 5 μg. To clarify this reason, we further analyzed the titers of FliC-specific IgG in sera. It was found that, the titers of FliC-specific IgG was 2-3 times higher than that of p24-specific IgG, particularly when FliC was 10 μg, the titer of FliC-specific IgG was 10 times higher than that of p24-specific IgG, ( FIG. 3 , E), indicating strong immunogenicity of FliC might interfere with the immune response of target antigens.
Embodiment 5
Solubility Studies of Flagellin Protein and Deletion Clones
[0042] In view of strong immunogenicity of FliC, and in view of its structure, namely N terminal (about 170 amino acids) and C terminal (about 100 amino acids) were very conservative and the TLR5 binding region, closely related with adjuvant activity, while the central regions (180-400 amino acids) were varied greatly both in amino acid sequence and size aspects, it was generally believed that they were related to the antigenicity, protein folding and adhesion of the flagellin protein. According to the literature, deletion of central hypervariable region does not affect the adjuvant activity of flagellin. We hypothesized that flagellin still had good adjuvant activity without the central 180-400 amino acid sequence. Based on this, we first constructed the flagellin deletion cloning FliCΔ180-400, but the FliCΔ180-400 structure was found unstable, it was expressed in inclusion body formation ( FIG. 4 , C, D and E). FIG. 4 shows the figures of related experiment of stability of hypervariable region deleted flagellin protein, wherein (A) shows the structure diagram of three constructed proteins with deletion, (B) shows the three dimensional structure of three constructed proteins being deleted, (C) shows the electrophoretogram of FliC and deletion clones in the insoluble fraction, (D) shows the electrophoretogram of FliC and deletion clones in the soluble fraction, and (E) shows the Western blot of FliC and deletion clones. Although protein dissolution could be obtained from inclusion body by denaturation and renaturation, but it was time-consuming and laborious, while the protein was also easy to get denaturated in the process of protein operation, and it is not advisable, particularly to the application-based protein such as adjuvant. Through consulting to related literature and using bioinformatics methods (http://www.expasy.org/spdbv/), we found that the greatest change in flagellin amino acid sequence placed in the region 190-350, wherein the hypervariable regions were concentrated at 190-280 and 220-320 two regions. So we also constructed FliCΔ190-278 and FliCΔ220-320 two clones, which respectively deleted 190-278 and 220-320 amino acids. Fortunately, these two clones with partially deleted hypervariable region were of good solubility ( FIG. 4 , C, D and E).
Embodiment 6
Experiment of Partial Deletion of Hypervariable Region Amino Acid Sequence Significantly Decreased the Antigenicity and Immunogenicity of Flagellin
[0043] To analyze the antigenicity and immunogenicity of deletion recombinant clones, BALB/c mice were intranasal immunized with FliC, FliCΔb 190 -278, FliCΔ220-320 and FliCΔ180-400 respectively, 2.5 ug/mouse, 5 mice/group, booster immunized one time after been primary immunized for 4 weeks, killed 2 weeks later. The blood samples were drawn from orbit. The titer of FliC-specific IgG and FliC-recombinant cloning-specific IgG in the serum was detected by ELISA. The result is shown in FIG. 5 , FIG. 5 shows the experimental result figures of the titer detection of FliC-specific IgG and FliC-recombinant cloning-specific IgG in the serum, wherein, (A) shows the comparison of titer detection of FliC-specific IgG in the serum by ELISA, and (B) shows the comparison of titer detection of FliC-recombinant cloning-specific IgG in the serum by ELISA. Compared with full-length flagellin FliC, deletion recombinant cloning all decreased flagellin's antigenicity and immunogenicity ( FIG. 5 , A and B), but FliCΔ190-278 was decreased 2-3 times compared to full-length, while FliCΔ220-320 and FliCΔ180-400 were decreased 100-200 times compared to full-length, eaching a significant difference (p<0.05) ( FIG. 5 , A and B).
Embodiment 7
FliCΔ190-278, FliCΔ220-320 and FliCΔ180-400 had Good Cell Stimulating Activity In Vitro
[0044] Whether the partial deletion or complete deletion of hypervariable region affected the structure of flagellin or the binding to TLR5, we detected the stimulation ability to Caco-2 cell of every deletion clones, using Caco-2 cell as model cell, and using IL-8 and MCP-1 as detect indexes. The deletion recombinant clones FliCΔ190-278, FliCΔ220-320 and FliCΔ180-400 were used to stimulate Caco-2 cell at different concentrations(0.1,1,10,100,1000, 10000 ng/ml), and the IL-8 and MCP- 1 were detected by ELISA. The results are shown in FIG. 6 . FIG. 6 shows the detection results of IL-8 and MCP-1 by ELISA after the deletion recombinant clones FliCΔ190-278, FliCΔ220-320 and FliCΔ180-400 were used to stimulate Caco-2 cell at different concentrations(0.1,1,10,100,1000, 10000 ng/ml), wherein (A) shows the detection results of IL-8 by ELISA, and (B) shows the detection results of MCP-1 by ELISA. It was found that, the deletion recombinant clones all had good cell stimulating activity at different concentration conditions. While, it was found that, when using low doses of 10 ng/ml, FliCΔ220-320 had good stimulating activity, by which the IL-8 level was induction released was equivalent with that of full length flagellin protein FliC, significantly higher than that of FliCΔ190-278 and FliCΔ180-400 ( FIG. 6 , A). Meanwhile, it was unexpectedly found in MCP-1 detection that, the MCP-1 induction released by deletion cloning FliCΔ190-278, FliCΔ220-320 and FliCΔ180-400 was significantly higher than that of full length flagellin protein FliC ( FIG. 6 , B) (p<0.05). It was speculated that, there may exist some kind of negative regulator in hypervariable region, but no relevant literature had been reported yet.
Embodiment 8
FliCΔ220-320 Had Better Mucosal Adjuvant Activity Than FliCΔ190-278 and FliCΔ180-400
[0045] To further analyze the mucosal adjuvant activity of recombinant clones, p24 was used as antigen (10 μg/mouse) and mixed with FliC, FliCΔ190-278, FliCΔ220-320 or FliCΔ180-400 (2.5 μg/mouse) respectively, and then used to immunize the BALB/c mice. CTB adjuvant (2 μg/mouse) was positive control, and PBS or p24 was negative control. The BALB/c mice were booster immunized one time after 4 weeks, killed 2 weeks after the last immunization. The sera, saliva, vaginal samples were obtained to detect titer of p24-specific and adjuvant-specific antibody by ELISA. The result is shown in FIG. 7 , FIG. 7 shows the result of titer detection of p24-specific and adjuvant-specific antibody in serum, saliva, vaginal samples by ELISA, with the p24 was used as antigen (10 μg/mouse) and mixed with FliC, FliCΔ190-278, FliCΔ220-320 and FliCΔ180-400 (2.5 μg/mouse) respectively, and then used to immune the BALB/c mice, wherein (A) shows the result of titer detection of p24-specific and adjuvant-specific IgG antibody in serum by ELISA, (B) shows the result of titer detection of p24-specific and adjuvant-specific IgA antibody in serum by ELISA, (C) shows the result of titer detection of p24-specific and adjuvant-specific IgA antibody in saliva by ELISA, (D) shows the result of titer detection of p24-specific and adjuvant-specific IgA antibody in vaginal by ELISA. Compared with control, flagellin deletion clones all had good adjuvant activity, wherein, the p24-specific IgG and IgA in serum of cloning FliCΔ220-320 immunized group had equivalent titer with that of full length flagellin FliC and CTB immunized group, with no significant difference. While the titer of p24-specific IgA in mucosa was significantly higher than that of full length flagellin FliC immunized group(p<0.05), equivalent with that of CTB immunized group, indicated good mucosal adjuvant activity ( FIG. 7 ). The p24-specific IgG in serum of FliCΔ190-278 and FliCΔ180-400 was significantly lower than that of full length flagellin FliC immunized group, the IgA titer in serum and mucosal was equivalent with or slightly higher than that of FliC immunized group, while significantly lower than that of CTB immunized group( FIG. 7 ). Considering the above, the cloning FliCΔ220-320 was the better mucosal adjuvant than full length flagellin protein FliC.
Embodiment 9
FliCΔ220-320 Showed Higher Safety
[0046] Flagellin was an application-oriented new adjuvant, its safety was our greatest concern, while, there were many mutual contradictory reports about safety question of flagellin. It was reported in literature that flagellin was related to Crohn disease, lung cysts etc.; it was reported that flagellin had anti-tumor, anti-bacterial, anti-virus function by the research group of Vijay-Kumar and Burdelya etc. In light of this situation, our group carried out a preliminary research on acute toxicity of the flagellin. Methods refer to “Guiding principles of chemical drugs'acute toxicity experiment”.
[0047] (I) Flagellin Had Potential Liver Acute Toxicity
[0048] Preexamination: 6-8 weeks old BALB/c SFP female mice were selected for toxicity test, and were divided into 4 groups with different dose 2.5 μg, 50 μg, 250 μg and 1000 μg/mouse (conventional adjuvant dose of flagellin FliC1 was 2.5 μg, toxicity test dose was equivalent to 1 times, 20 times, 100 times and 400 times of the conventional adjuvant dose), 5 mice/group, and were intranasal immunized with the dose of 1000 μg/mouse. Negative control group were immunized with same volume of PBS, nonspecific protein control group were immunized with the HIV core antigen protein p24 which was purified in our laboratory. Conventional fed after immunization, continuous observed for 7 days, and the weight of mice and symptoms of animal toxicity reaction were daily recorded. Results: (1) observation of toxic symptoms: the FliC1 high dose group (that is 1000 μg/mouse) performed less spontaneous activity after the immunization for 48 h, fixed reposed with hair rough, reactivated at 48 th hour-72th hour, the spirit and foraging situation returned to normal after 72 h; the FliC1 low dose group of 2.5 μg/mouse and 50 μg/mouse showed normal activity as control group of p24 and PBS, had no significantly abnormal reaction. (2) changes of mice weight: the weight of FliC1 1000 μg group was severely lost, kept losing within 2 days after the immunization, and became lightest at the 2 nd day and the 3 rd day, the weight lost 20% compared with that before immunization, and became restored to some extent subsequently, while average lost 15% compared with that before immunization, and still not restored at the 6 th day; the weight of FliC1 250 μg group showed the same decrease trend as the 1000 μg group, but lost less with about 11% of weight, while became restored to some extent after the 3 rd day, average lost 6% compared with that before immunization; the weights of FliC1 2.5 μg group and 50 μg group were decreased for one day after immunization, average lost 20% compared with that before immunization, and became restored to some extent subsequently, restored to 98% of that before immunization; the weight of p24 group was decreased slightly compared to that before immunization, lost about 1%. The weight of PBS control group had not decreased during the immunization process. The result is shown in FIG. 8 , FIG. 8 shows result figures of toxicity test preexamination, the mice were intranasal immunized, conventional fed after immunization, continuous observed for 7 days, and the weights of mice were daily recorded. Comprehensive considered the above two points: flagellin had dose-effect, barely effected at 2.5 μg/mouse, slightly effected at 50 μg/mouse within 24 h, the mice began to recover fastly after 24 h, and the dose of 250 μg and 1000 μg had severely toxicity to the mice, the toxicity of 250 μg was milder than that of 1000 μg. C57BL/6 mice showed the same reaction as that of BALB/c mice, and the data is not shown.
[0049] Formal tests: based on the above preexamination, for further analysis of the flagellin effect on every organs, the C57BL/6 mice were intranasal immunized with FliC1 250 μg, 5 mice/group, and the negative control were the mice without any treatment and the mice only immunized with PBS. They were killed respectively at 6 th hour, 12 th hour, 24 th hour, 36 th hour, 48 th hour, and a week after immunization. (1) Biochemical analyzed the biochemical indexes ALT and AST in serum reflecting liver injury, the biochemical indexes TP and ALB reflecting liver synthesis and reserve function, the TBiL and DBiL reflecting liver secretion and excretion function, and the BUN and CREA reflecting renal function lesions; (2) visual inspected possible pathological changes of mice organs in anatomization, and fixed and embedded the heart, liver, spleen, lung, renal and small intestine tissue, observed histopathological features of every organs after HE staining.
[0050] (1) system anatomical observation: related experiment result is shown in FIG. 9 , FIG. 9 shows the liver lesions, the C57BL/6 mice were intranasal immunized with FliC1 and killed respectively at 6 th hour, 12 th hour, 24 th hour, 36 th hour, 48 th hour, and a week after immunization, wherein, figure A shows the result figure of anatomized mice liver surface of PBS group, figure B1 shows the result figure of liver surface of treated group killed at 12 th hour, figure B2 shows the result figure of liver surface of treated group killed at 24 th hour, figure B3 shows the result figure of liver surface of treated group killed at one week, figure C shows the comparison figure of observed histopathology of liver of FliC immunized group. When the mice were anatomized, the heart, liver, spleen, lung, renal and small intestine tissue had not been visual inspected lesion. The liver of FliC1 immunized group showed significant lesion, showed red spots on the surface of the liver at 12 th hour, the spots size were small, mainly focused on liver edge ( FIG. 9 , B1), the spots turned red to white and became bigger, extended from the edge toward the center, at 24 th hour the white spots were visible everywhere in the whole surface of the liver ( FIG. 9 , B2), and this phenomenon was kept until 48 th hour with the size and the number of the spots were reduce, the surface of the liver had not present significant white spots at one week ( FIG. 9 , B3). The surface of the mice liver of PBS group which were anatomized at the same time in process had not present any spot ( FIG. 9 , A).
[0051] (2) histopathological observation: after the above tissues were fixed with formalin, embedded in paraffin, and HE stained, the pathological changes of the tissues were observed. It is shown that: in the FliC1 immunized group, the heart, spleen, renal and small intestine tissues had not been pathological changed, the liver had severe lesion. The result is shown in FIG. 10 , FIG. 10 shows liver lesion observed at different times of FliC1 immunized group, wherein, figure A shows the HE staining result figure of liver tissue of PBS group, figure B1 shows the HE staining result figure of liver tissue of treated group killed at 12 th hour, figure B2 shows the HE staining result figure of liver tissue of treated group killed at 24 th hour, figure B3 shows the HE staining result figure of anatomized mice liver tissue of treated group killed at one week. Specifically, the liver at 6 th hour had not present abnormality compared with the blank control group and the PBS control group, the livers at 12 th hour-48 th hour had clear structures but turned out liver necrosis, and the liver necrosis accompanied with hemorrhage at 12 th ( FIG. 10 , B1), the liver at 24 th got worst, massive liver necrosed, and necrotic spot was large( FIG. 10 , B2), and the livers at 36 th and 48 th had the same symptoms as that at 24 th , while the symptoms at 24 th was mild, the liver of the mice anatomized at one week had not present necrotic spot, while the structure of liver cord and liver sinusoidal was not clear, the liver swelled and occurred vacuolar degeneration ( FIG. 10 , B3).
[0052] (3) Serum biochemical indexes analysis: according to the results of morphological and histopathological observation, the mice serum was biochemical analyzed (by biochemical analyzer), the result is shown in FIG. 11 , FIG. 11 shows the biochemical analysis result figures of biochemical indexes reflecting liver injury, using the serum of the FliC1 immunized group, wherein, figure A, B, C, D, E, F, G and H were the biochemical analysis result figures of ALT, AST, TP, ALB, TBiL, DBiL, BUN and CREA, respectively. The figure shows that: in the serum of the FliC1 immunized group, the TP and ALB ( FIG. 11 , C and D),TBiL, DBiL( FIG. 11 , E and F), and BUN, CREA ( FIG. 11 , G and H) were not differ from that of the blank control group and the PBS group. The ALT and AST values increased at the 12 th hour after the immunization, and reached the peak 600 IU/L at 24 th hour. The ALT and AST values increased significantly compared with that of the PBS group, 10 times and 4 times of that of PBS group, suggesting that massive liver cells were injured. The ALT and AST values decreased after 24 th hour, and reached the background level in one week after the immunization.
[0053] Comprehensively considered the above three points, the intranasal immunization with flagellin had severe liver toxicity.
[0054] (II) FliCΔ220-320 significantly decreased liver toxicity compared with the full length flagellin
[0055] To analyze the liver toxicity of deletion recombinant cloning and the full length flagellin, the C57BL/6 mice 6-8 weeks old were divided into 5 groups of blank control group, vehicle group (the PBS group), FliC, FliCΔ220-320 and FliCΔ180 -400 group, and were intranasal immunized, 250 μg/mouse. The mice were kept fasting (not fasting in liquid) overnight before immunization, and were killed respectively at 6 th hour, 12 th hour, 24 th hour, 36 th hour, 48 th hour, and a week after immunization. The heart, liver, spleen, lung, renal and small intestine tissue were fixed and embedded, made into paraffin sections, observed histopathological changes of organs. The result is shown in FIG. 12 , FIG. 12 shows related experiment results of FliCΔ220-320 safety, wherein, figure A shows the comparison figure of ALT and AST concentration in serum of the FliC immunized group, figure B shows the comparison figure of liver anatomical observation of the FliC immunized group, figure C shows the comparison figure of liver histopathological observation of the FliC immunized group. Specifically, the result is shown in FIG. 12 : the ALT and AST values of the FliC immunized group increased 5-10 times of that of the blank control group and the PBS group, reached peak at 24 th hour, and decreased subsequently, and reached the background level in one week after the immunization; the ALT and AST values were equivalent in the FliCΔ190-278 immunized group and the FliC immunized group; the ALT value of the FliCΔ180-400 immunized group increased significantly, equivalent with the peak of the FliC immunized group, reached peak at 24 th hour, rapid decreased subsequently, and reached the background level at 48 th hour, while the AST value increased slightly from the 24 th hour to 36 th hour, and its peak value was 2-3 times of the blank control group and PBS group, and then decreased subsequently, and reached the background level at 48 th hour; the ALT and AST values of the FliCΔ220-320 immunized group had not rose during the process, were equivalent with the blank control group and the PBS group ( FIG. 12 , A); other biochemical indexes of flagellin FliC, FliCΔ220-320 and FliCΔ180-400 immunized group were not differ from the control group. (2)anatomical observation: the liver of FliC1 immunized group showed red spots on the surface of the liver at 12 th hour, the spots size were small, mainly focused on liver edge, and at 24 th hour the spots turned red to white and became bigger, extended from the edge toward the center, the white spots were visible everywhere in the whole surface of the liver, this phenomenon existed at 48 th hour, but the size and the number of the spots were reduce, the surface of the liver in the group killed at one week had not present significant white spots ( FIG. 12 , B). The symptoms of the FliCΔ190-278 immunized group were as the same as that of the FliC immunized group, with massive white necrotic spot presented on the surface of the liver. The surface of the mice liver of FliCΔ220-320 and FliCΔ180-400 immunized group which were anatomized at 24 th hour-48 th hour showed a few white spots, and the spots were small, at one week there was no white spot. (3)histopathological observation: liver: the FliC immunized group showed massive liver cell necrosis, accompanied with massive inflammatory cells infiltration, the symptoms were severely, especially in the phase of 24 th hour-48 th hour. It was almost anastomosed to the observation of anatomy ( FIG. 12 , C). The FliCΔ220-320 and FliCΔ180-400 immunized groups also showed liver cell necrosis in the phase of 24 th hour-48 th hour, but the necrotic foci appeared were only a few, the symptoms were mild. The other organs of flagellin immunized group showed no significant toxicity both in anatomical observation and histological observation. Comprehensive considered the biochemical indexes, the Flic anatomical observation and the histological observation, FliC showed potential acute toxicity of liver cells. Full deletion of hypervariable region, or deletion of hypervariable region in 220-320 amino acid sequences, significantly decreased the toxicity of flagellin. Comprehensive considered the biochemical indexes in serum, FliCΔ220-320 showed higher safety than FliC, FliCΔ190-278 and FliCΔ180-400.
[0056] In the above experiments, the operation of antibody titer detection in serum and mucosal by ELISA, were as follows:
[0057] the antigen was diluted to 3 μg/ml with coating buffer, 4° C. overnight; washed by 270/well, three times, 5 min each; blocked with blocking solution (PBS +0.05% Twee-20) 250 μg/well, incubated 1˜2 h at 37° C.; the samples were gradient diluted by 4 times, and loaded into well, incubated 1˜2 h at 37° C.; washed and added AP-conjugated secondary antibody (1:2000); incubated 1˜2 h at 37° C.; washed and added AP chromogenic substrate; colored 30 min at 37° C., and OD405 absorption value was read. The antibody titer was defined as the maximum dilution multiple of serum when the optical absorption ratio >2.0 between the experimental group and the negative control group.
[0058] It should be noted that the scope of the present invention is not limited by the embodiments, while the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | The present invention provides an optimized recombinant flagellin protein and preparation and use thereof. The protein is with a deletion in the hypervariable region, said hypervariable region is the region from 180 to 400 amino acid of the flagellin protein, and the proteins include FliCΔ190-278, FliCΔ220-320 or FliCΔ180-400. The method of preparing said protein, comprising introducing a deletion into the hypervariable region of the flagellin protein. First constructed the flagellin protein recombinant plasmid, and then used it as template to construct the flagellin deletion cloning, and expressed and purified. The present invention also provides the use of the recombinant flagellin protein as adjuvant. The recombinant flagellin protein in present invention decreases the potential risks it may have, and decreases its antigenicity and immunogenicity and the inflammatory response induced by it, through deleting its main areas of immunogenicity and antigen activity. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority from U.S. Provisional Patent Application Ser. No. 60/703,114, filed Jul. 27, 2005 and entitled “Queuing and Scheduling Architecture Using Both Internal and External Packet Memory for Network Switching Devices,” which is fully incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Generally, this disclosure relates to network devices. More specifically, it relates to systems and methods associated with queuing and scheduling architecture of network appliances that are capable of supporting wired or wireless clients while using both internal and external packet memory.
[0004] 2. Description of the Related Art
[0005] The Wireless Local Area Network (WLAN) market has experienced rapid growth in recent years, primarily driven by consumer demand for home networking. The next phase of the growth will likely come from the commercial segment comprising enterprises, service provider networks in public places (e.g., Hotspots, etc.), multi-tenant multi-dwelling units (MxUs) and small office home office (SOHO) networks. The worldwide market for the commercial segment is expected to grow from 5M units in 2001 to over 33M units this year, in 2006. However, this growth can be realized only if the issues of security, quality of service (QoS) and user experience are effectively addressed in newer products.
[0006] FIG. 1 illustrates an exemplary wired network topology 100 as is known in the art today. As shown in FIG. 1 , network 100 can be connected to another external network 110 (e.g., the Internet, an extranet, an intranet, etc.) via a virtual private network (VPN) and/or firewall 115 , which can in turn be connected to a backbone router 120 . Backbone router 120 can be connected to other network routers 130 , 150 , as well as one or more servers 125 . Router 130 can be connected to one or more servers 135 , such as, for example, an email server, a DHCP server, a RADIUS server, and the like. Further, router 130 can be connected to a level 2 /level 3 (L 2 /L 3 ) switch 140 , which can be connected to various wired end user, or wired client, devices 145 . Wired client devices 145 can include, for example, personal computers, printers, workstations, scanners, and other similar devices. Router 150 can also be connected to one or more L 2 /L 3 switches 155 , 160 . Switch 160 can then be connected to one or more wired client devices 165 , which can be similar to end user devices 145 .
[0007] FIG. 2 illustrates an exemplary unified wired and wireless network topology 200 as is known in the art today. Much of this network is as discussed above with reference to FIG. 1 . However, additional wired and wireless elements have been added. As additionally shown in FIG. 2 , router 155 is connected to wired client devices 258 , which can be similar to wired client devices 145 , 165 . Further, L 2 /L 3 switches 140 , 160 are additionally connected to wireless access point (AP) controllers 285 , 270 , respectively. Each AP controller 285 , 270 can be connected to one or more wireless access points 290 , 275 , respectively. Additional wireless client devices 295 , 280 can be wirelessly coupled to wireless APs 290 , 275 , respectively. Wireless client devices 295 , 280 , such as desktop computers, laptop computers, personal digital assistants (PDAs), wireless telephones, wireless media players, etc., can connect via wireless protocols such as IEEE 802.11a/b/g/n, IEEE 802.16, and the like to wireless APs 290 , 275 . More access points can be connected to wireless AP controllers 285 , 270 . Switches 140 , 155 , 160 can each be connected to additional wireless access points, access point controllers, and/or other wired and/or wireless network elements such as switches, bridges, routers, computers, servers, and so on. Many possible alternative topologies are possible; as such, FIG. 2 (and FIG. 1 ) is intended to illuminate, rather than limit, the scope of this disclosure.
[0008] Unlike wired networks, as illustrated in FIG. 1 , networks that include wireless elements, as in FIG. 2 , pose unique challenges, especially in terms of supporting Quality of Service (QoS) for various applications. In a wired enterprise network, packets are typically queued and scheduled using a simple priority-based queuing structure. This is adequate for most applications in terms of service differentiation. However, in wireless networks (i.e., networks that support at least one wireless element), the bandwidth supported to the wireless clients is typically much less than in the wired networks to which the wireless elements are connected. For example, an access point (AP) supports 11 Megabits per second (Mbps) if it is using the IEEE 802.11b protocol and up to 54 Mbps if it is using the IEEE 802.11g protocol. The typical wireless client receives data from the AP using a contention-based protocol, which means they are sharing the available bandwidth. The upstream switch to which the AP controller (and thus the AP) is connected is receiving data at 100 Mbps or even 1 Gigabits per second (Gbps) from its upstream connections for these wireless clients.
[0009] A typical implementation of a network device includes a packet memory to store the packets, and queues to organize the packets into an ordered list. Packets arriving at the device are typically stored in the packet memory while they wait to depart on the desired interface. Packets waiting for departure are organized using queues. Packets can be associated with different queues on the same interface, for example, based on their priority or class of service, and different scheduling mechanisms can be used to decide which queue or packet to serve first.
[0010] In typical architectures, queues are either implemented as static first-in, first-out (FIFO) queues, or dynamically organized into linked lists. In the former (i.e., FIFO queues), the packet memory is statically partitioned so that specific locations are associated with specific queues. In the latter (i.e., dynamic queues), packet memory locations are associated with different queues at different times based on demand. In conventional systems today, packet memory is implemented either entirely in internal memory or entirely in external memory, and typically never in a combination of the two. Likewise, queues in conventional systems are typically implemented entirely in either internal or external memory. As used herein, internal memory refers to any type of network device traffic storage that is integral to, e.g., on-chip with, the processing logic of the network device and external memory refers to any type of network device traffic storage that is not integral to, e.g., off-chip to, the processing logic.
[0011] The use of internal memory can result in a system with higher bandwidth, but the amount of packet buffer integrated on-chip can be limited by chip size and cost. On the other hand, using external memory can provide a large amount of packet storage, but at a lower memory throughput. Typical systems are built using either external or internal memory: external memory when it needs to handle large burst traffic conditions or mismatched link speed, or internal memory when it only needs to handle more ‘normal’ traffic conditions.
[0012] In the above mentioned unified network topology, as illustrated in FIG. 2 , the wired traffic typically needs small memory storage (e.g., internal memory), while large storage (e.g., external memory) is needed for wireless traffic because of a mismatch in link speeds between ingress and egress links. However, as the wireless traffic is only a subset of the total unified network traffic, the external memory bandwidth requirement can be limited to a much smaller value. Therefore, what is needed is sophisticated queuing and scheduling architecture in a network appliance, such as a unified wired/wireless network device, that can facilitate, among other things, the capability of using both internal memory and external memory for packet memory or queues based on the traffic type.
SUMMARY OF THE DISCLOSURE
[0013] Enhanced memory management schemes are presented to extend the flexibility of using either internal or external packet memory within the same network device. In the proposed schemes, the user can choose either static or dynamic schemes, both or which are capable of using both internal and external memory, depending on the deployment scenario and applications. This gives the user flexible choices when building unified wired and wireless networks that are either low-cost or feature-rich, or a combination of both.
[0014] A method for buffering packets in a network device, and a network device including processing logic capable of performing the method are presented. The method includes initializing a plurality of output queues, determining to which of the plurality of output queues a packet arriving at the network device is destined, storing the packet in one or more buffers, where the one or more buffers is selected from a packet memory group including an internal packet memory and an external packet memory, and enqueuing the one or more buffers to the destined output queue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Aspects and features of the present invention will become apparent to those ordinarily skilled in the art from the following detailed description of certain embodiments of the invention in conjunction with the accompanying drawings, wherein:
[0016] FIG. 1 illustrates an exemplary wired network topology as is known in the art today;
[0017] FIG. 2 illustrates an exemplary unified wired and wireless network topology as is known in the art today;
[0018] FIG. 3 illustrates an exemplary packet memory according to certain embodiments;
[0019] FIG. 4 illustrates an exemplary unicast pointer memory according to certain embodiments;
[0020] FIG. 5 illustrates an exemplary multicast pointer memory according to certain embodiments;
[0021] FIG. 6 illustrates exemplary queues and queue memory according to certain embodiments;
[0022] FIG. 7 illustrates an exemplary static configuration in operation according to certain embodiments; and
[0023] FIG. 8 illustrates an exemplary dynamic configuration in operation according to certain embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Embodiments will now be described in detail with reference to the drawings, which are provided as illustrative examples so as to enable those skilled in the art to practice the embodiments and are not meant to limit the scope of the disclosure. Where aspects of certain embodiments can be partially or fully implemented using known components or steps, only those portions of such known components or steps that are necessary for an understanding of the embodiments will be described, and detailed description of other portions of such known components or steps will be omitted so as not to make the disclosure overly lengthy or unclear. Further, certain embodiments are intended to encompass presently known and future equivalents to the components referred to herein by way of illustration.
[0025] In certain embodiments, packet memory can be used to implement a sophisticated, high-performance queuing architecture that can require external packet memory to operate. While the term packet will be used throughout this disclosure to illustrate certain embodiments, it is intended that such embodiments only exemplary, and that the teachings are equally applicable to any type of network traffic, such as datagrams, frames, and other similar data, regardless of the communications layer or layers in which the implementing network device is operating. This typically translates into additional system cost due to the memory chips and circuit board complexity. To reduce this limitation, certain embodiments introduce a novel micro-architecture for the network device that can selectively leverage both on-chip, or internal, packet memory and off-chip, or external, packet memory. Systems can be built according to certain embodiments without external memory to reduce the cost, or with limited external memory to increase performance for a subset of the traffic (e.g., burst traffic, mismatched link speeds, etc.) that may otherwise result in dropped packets if internal memory, when used alone, could not absorb the packets.
[0026] According to certain embodiments, there are at least four kinds of memory in the proposed implementation: packet memory, unicast pointer memory, multicast pointer memory, and queues. While the at least four kinds of memory are illustrated herein for completeness, certain embodiments can also be used within a unified device as disclosed in U.S. patent application Ser. No. 11/351,330, filed on Feb. 8, 2006 to Seshan et al. and entitled “Queuing and Scheduling Architecture for a Unified Access Device Supporting Wired and Wireless Clients,” which is fully incorporated herein by reference. Each of the at least four kinds of memory are briefly discussed below.
[0027] FIG. 3 illustrates an exemplary packet memory 300 according to certain embodiments. As shown in FIG. 3 , packet memory 300 can be both internal memory 310 and/or external memory 320 . Internal packet memory 310 can be, for example, on-chip memory of a type and size as design constraints dictate. External packet memory 320 can be, for example, off-chip memory of a type and size as design constraints dictate. Internal and external packet memories 310 , 320 can be used to store buffered packets 315 , 325 , respectively. Packet memory 300 can be divided into large fixed-size buffers that are big enough to hold the maximum sized packets (e.g., 1500 bytes for each TCP/IP datagram); or it can be divided into smaller buffer cells (e.g. 128 bytes each) so that a packet is stored in multiple cells that can be chained together. In general, the packet-based packet memory architecture is simpler, but the cell-based packet memory architecture can potentially use memory more efficiently. Certain embodiments are equally applicable to both (or either) packet-based architecture and cell-based architecture.
[0028] FIG. 4 illustrates an exemplary unicast pointer memory 400 according to certain embodiments. As shown in FIG. 4 , unicast pointer memory 400 is memory, which can be similar to packet memory 300 and also can include internal memory 410 and/or external memory 420 , can be used to describe the content of packet memory locations 415 , 425 . It also can contain pointers to chain packets together to form a queue. Each internal and external packet memory block 315 , 325 can be associated with an internal and external unicast pointer memory 415 , 425 , respectively. Unicast pointer memory can additionally include the following information (i.e., one or more bits each): next pointer type 430 , count info 440 , length info 450 , ingress port info 460 and next pointer 470 . Next pointer type 430 can indicate whether the next pointer points to a multicast pointer, in the multicast pointer memory, or another unicast pointer, in the unicast pointer memory. Count info 440 can indicate the replication count for associated data in the packet memory. For multicast packets, count info 440 can indicate the number of multicast pointers that point to this particular packet pointer. Length info 450 can indicate the size of the packet. Ingress port info 460 can indicate from where the associated packet came. Next pointer info 470 can point to either the next unicast pointer or multicast pointer, depending on next pointer type 430 . Next pointer info 470 can point to itself, for example, if there are no packets behind the current packet associate with current next pointer info 470 .
[0029] FIG. 5 illustrates an exemplary multicast pointer memory 500 according to certain embodiments. As shown in FIG. 5 , multicast pointer memory 500 is a piece of internal and/or external memory that can be used to chain multicast packets, as indicated by next pointer type 430 from unicast pointer memory 400 , into a queue. Multicast pointer memory 500 can have a buffer pointer 550 that points to the unicast pointer memory that is associated with where the actual multicast packet is stored. Similar to unicast pointer memory 400 , multicast pointer memory 500 can also have multicast info 530 , count 540 and next pointer 560 , which allows it to point to the next packet in the queue.
[0030] FIG. 6 illustrates exemplary queues and queue memory 600 according to certain embodiments. As shown in FIG. 6 , each queue, generally, can have one or more of the following pieces of information (i.e., one or more bits each): queue ID, queue head, queue tail, queue length and internal/external indicator. Queue ID identifies the particular queue. Queue head is a pointer that points to the first packet of the queue, with the multicast bit to indicate whether the first packet in the queue is a multicast or unicast packet. Queue tail is a pointer that points to the last packet of the queue. The queue length field records the number of packets in the queue. Internal/external indicator provides whether a particular queue uses internal or external memory. Besides the egress queues 630 , 640 , there can be other special queues: free internal queue 610 , free external queue 615 and free multicast queue 620 . Free internal/external queues 610 , 615 , respectively, can maintain a list of unused unicast pointers (e.g., internal or external) and free multicast queue 620 can maintain a list of unused multicast pointers.
[0031] According to certain embodiments, two broad categories of configurations are disclosed to facilitate the use of internal and external packet memory in a network device: a static configuration and a dynamic configuration, which are not necessarily mutually exclusive of each other. Further, within each of these two broad categories, there are at least three kinds of queues: internal queues, external queues and aggregate queues. For an internal queue, all associated packet memory is internal memory, while for an external, all associated packet memory is external memory. However, for an aggregate queue, the associated packet memory can be both internal and external packet memory.
[0032] Generally, in a static configuration according to certain embodiments, each output queue can be pre-configured, or designated, for example during the initialization process, to be an internal queue, an external queue or an aggregate queue. Alternatively, to build a static system without external memory, all queues would be programmed to use internal memory. If external memory is available, a user can assign queues to use either internal memory, external memory or both, depending on the operational needs of the network device implementing the static configuration. For example, all of the output queues associated with wired traffic might be assigned to use internal memory, while queues handling wireless traffic could use external memory to facilitate buffering packets because of mismatched link speeds. Further, for handling multicast traffic or mirrored traffic, the aggregate queues could be used.
[0033] Generally, in a dynamic configuration according to certain embodiments, all of the output queues can be configured to dynamically and selectively use and alternate between both internal and external packet memory. For these queues, if both types of packet memory are available, internal memory can be used first. If there is no internal memory available, either because it does not exist of because it is currently full, external memory can be used. In this regard, external memory can serve as an “overflow buffer” during, for example, a burst-traffic condition. During a normal-traffic condition, all packets destined to dynamic queues can use internal memory.
[0034] FIG. 7 illustrates an exemplary static configuration 700 in operation according to certain embodiments. As shown in FIG. 7 , the exemplary elements described above in relation to FIGS. 3-6 are interactively linked. Unicast packet pointers 410 (i.e., pointers 0 to 1023 ) can be used in conjunction with internal packet memory 310 , and unicast packet pointers 410 (i.e., pointers 1024 to 33791 ) can be used for external memory. There are two free buffer queues, one for internal memory 610 and one for external memory 615 . In certain embodiments, each queue can have one or more bits indicating whether internal, external or both should be used for a particular egress queue 630 . If the internal/external indicator is set as internal, then this internal queue should use internal memory. If the internal indicator/external is set as external, then this external queue should use external memory. If the internal/external indicator is set for both, then this aggregate queue can use both, or either, internal and external memory.
[0035] For certain embodiments of the static configuration, three exemplary implementation schemes are presented. The use of one particular scheme over another depends on system requirements. In the first scheme, each physical port of the implementing network device can have two packet buffers, one internal 310 and one external 320 , that are allocated and waiting for incoming packets. Internal packet buffer 310 is allocated from internal free queue 610 and external packet buffer 320 comes from external packet queue 615 . Those packet buffers can serve as temporary storage for incoming packets while they are processed by the ingress pipeline of the network device. During the packet reception phase, each incoming packet can be stored in both internal and external packet buffer at the same time. The packet can be enqueued to egress queue once the forwarding decision is made by the ingress pipeline. Alternatively, for systems with only one type of packet memory (e.g., internal or external), all queues (and multicast memory) should be initialized to use that memory type.
[0036] In the above mentioned scheme, each packet can be stored both in internal memory and external memory. Once the information about the outgoing queue (i.e. internal, external, etc.) is available, then depending on the queue configuration, either the internal or external buffer can be discarded. For packets destined to internal queue the packet is stored both in internal and external memory. For these packets the bandwidth needed to write a packet to the external memory is wasted. Hence, the above scheme works best, but not exclusively, if the bandwidth to external memory is not limited as compared to the internal bandwidth.
[0037] In the second exemplary static configuration scheme, if the information about the destination queue is available before the packet data arrives, then the first exemplary scheme can be modified to store the packet directly into an internal or external buffer. In this way, the implementing network device can function even with very limited external memory. But this scheme does not handle the scenario where a burst of packets should be stored in the external memory as efficiently as the first scheme.
[0038] To handle the above drawbacks the following, third exemplary static configuration scheme can be used. A transfer queue consisting of a small number of internal packet buffers can be maintained. Each physical port of the implementing network device can have an internal packet buffers that is allocated and waiting for incoming packets. These packet buffers can serve as temporary storage for incoming packets as they are processed by the ingress pipeline of the network device. Based on packet forwarding logic or packet classification, the ingress pipeline can determine the appropriate egress queue. In case the egress queue is configured as an internal queue (i.e. the packets for this queue should be stored in the internal memory) the packet buffer can be directly linked to the egress queue. However, if the packet is destined for an external queue, then the packet buffer is first linked to the transfer queue. The packets are then transferred from the transfer queue to external memory, which is then linked to the egress queue.
[0039] For multicast and broadcast packets in each of these three exemplary static configuration schemes, the packet buffer needs to be enqueued to multiple queues. These queues can be configured internal, external or aggregate queues. If the outgoing queue 630 is configured to use internal memory, then the internal packet buffer 310 will be enqueued to the output queue. If the outgoing queue 630 is configured to use external memory, then external packet memory 320 will be enqueued to the output queue. In this exemplary static configuration, a multicast packet may consume two or more packet buffers if the multicast includes output queues using both internal and external packet memories 310 , 320 .
[0040] An alternative approach for handling multicast and broadcast packets would be through the use of aggregate queues. Here each multicast cast group or the broadcast group can be designated as internal or external. Thus, the multiple multicast or broadcast groups can be mapped to the same aggregate queue. If the group is set to internal then internal packet buffer 310 can be used, otherwise external packet memory 320 can be used for the group. In this way, only one copy of the multicast packet would need to be stored. As a simplification of this, all multicast and broadcast groups can be designated as internal or external.
[0041] Packets which are mirrored or copied can also be enqueued to multiple queues. The queue designated for forwarding the packet is referred to as a forwarding queue. If these queues are configured as either internal or external then as mentioned above either the internal or external packet buffer 310 , 320 is used. An alternate mechanism would be to assign aggregate queues for mirrored or copied packets. Here the packet can be enqueued using the internal or external buffer based on the forwarding queue configuration.
[0042] FIG. 8 illustrates an exemplary dynamic configuration 800 in operation according to certain embodiments. As shown in FIG. 8 , the exemplary dynamic configuration generally operates the same as previously discussed in relation to FIG. 7 , especially in relation to similarly labeled components, with the following exception: instead of statically assigning all queues to a particular buffer type, at least some queues can be dynamic queues. In this way a dynamic queue can be considered a queue property, and not necessarily a port property. In one possible implementation, it is assumed that buffers in the internal memory 310 will be used before buffers in the external memory 320 . Thus, output queues 640 no longer require the internal info that was included with output queues 630 of FIG. 7 . But as previously discussed, other schemes for dynamic configuration are intended to be within the scope of this disclosure.
[0043] For dynamic configuration, similar to static configuration discussed above, multicast or broadcast packets should be enqueued on multiple queues. It is possible that one of the queues can be designated dynamic, while other queues are designated internal. In such a situation, the multicast or broadcast packet can be, for example, preferably stored in the internal memory. However, in cases where all queues are dynamic, then the packet can be stored using either internal or external packet buffer based on system design. For example, a particular implementation could store these packets in external memory if the number of packets for any of the output queues is beyond some configured value. The decision to choose internal or external buffer could also be based on some predetermined configuration. However, if in a system it is possible that multiple dynamic queues would be full at the same time and the external memory bandwidth would not be sufficient to handle the burst traffic, then the transfer queue mechanism described above for static configuration can be used. These same implementations can be followed in the case of mirrored packets and/or copied packets.
[0044] In certain embodiments, both static and dynamic configurations can be applied to cell-based packet memory architecture. In cell-based packet memory architecture, a packet is stored in one or multiple memory cells. A cell can be physically located in either internal or external memory and a packet can be stored across multiple cells of both memory types. In a static configuration, each port of the network appliance should allocate to multiple cells, large enough to hold a single packet from either or both internal and external packet memory. A packet can be stored in either internal cells or external cells, depending on the outgoing queue. In a dynamic configuration, if there are not enough free internal memory cells to store an entire packet, external memory can be used so that a single packet need not be stored in a mix of internal and external cells. However, mixed storage can be accomplished using the cell-based packet memory architecture according to certain embodiments.
[0045] Although the present invention has been particularly described with reference to embodiments thereof, it should be readily apparent to those of ordinary skill in the art that various changes, modifications, substitutes and deletions are intended within the form and details thereof, without departing from the spirit and scope of the invention. Accordingly, it will be appreciated that in numerous instances some features of the invention will be employed without a corresponding use of other features. Further, those skilled in the art will understand that variations can be made in the number and arrangement of inventive elements illustrated and described in the above figures. It is intended that the scope of the appended claims include such changes and modifications. | Enhanced memory management schemes are presented to extend the flexibility of using either internal or external packet memory within the same network device. In the proposed schemes, the user can choose either static or dynamic schemes, both or which are capable of using both internal and external memory, depending on the deployment scenario and applications. This gives the user flexible choices when building unified wired and wireless networks that are either low-cost or feature-rich, or a combination of both. A method for buffering packets in a network device, and a network device including processing logic capable of performing the method are presented. The method includes initializing a plurality of output queues, determining to which of the plurality of output queues a packet arriving at the network device is destined, storing the packet in one or more buffers, where the one or more buffers is selected from a packet memory group including an internal packet memory and an external packet memory, and enqueuing the one or more buffers to the destined output queue. | 7 |
TECHNICAL FIELD
[0001] The present invention relates to communication networks, and, more particularly, to a method and apparatus for adjusting a symbol decision threshold at a receiver in a communication network.
BACKGROUND
[0002] Data communication networks may include various routers and switches coupled together and configured to pass data to one another. These devices will be referred to herein as “network elements.” Data is communicated through the data communication network by passing protocol data units, such as Internet Protocol packets, Ethernet Frames, data cells, segments, or other logical associations of bits/bytes of data, between the network elements by utilizing one or more communication links between the network elements. A particular protocol data unit may be handled by multiple network elements and cross multiple communication links as it travels between its source and its destination over the network.
[0003] The various network elements on the communication network communicate with each other using predefined sets of rules, commonly referred to as protocols. Different protocols are used to govern different aspects of the communication, such as how signals should be formed for transmission between network elements, various aspects of what the protocol data units should look like, how protocol data units should be handled or routed through the network by the network elements, and how information such as routing information should be exchanged between the network elements.
[0004] At the physical layer, in a digital communication network, the network elements transmit and receive binary signals that represent either zeros or ones. There are several ways that this may be implemented, depending on the type of physical media being used to transport the signals. Where the network elements are communicating over an optical fiber 14 , for example as shown in FIG. 1A , the transmitter 10 may transmit binary signals by turning a laser on and off. Where an electrically conductive physical medium 16 is used, as shown in FIG. 1B , the binary signals may be formed by adjusting a voltage on the conductor. Where the network elements are communicating using a wireless protocol as shown in FIG. 1C , the binary signals may be encoded onto the carrier frequency 18 being used by the network elements to communicate with each other. Regardless of the particular physical medium in use, the transmitter 10 will transmit a series of zeros and ones which will be received by the receiver 12 , so that the transmitter is able to convey information to the receiver.
[0005] When a signal is transmitted on a fiber, electrical cable, wireless carrier, etc., it is possible for the signal to be distorted during transmission. Thus, when the receiver receives the signal, there is a possibility that the received signal will include an error component. Likewise, the receiver and transmitter are generally required to operate at the same frequency so that the receiver reads data from the signal at the same rate that the transmitter transmitted the data on the signal. An explicit clocking signal may be used to synchronize the transmitter and receiver or, alternatively, the receiver may extract synchronization information from the received waveform.
[0006] FIG. 2 shows an example transmitter/receiver combination that may be used to transmit data between a transmitter 10 and receiver 12 over an optical, electrical, or wireless physical medium. The example shown in FIG. 2 is designed to enable the receiver to correct errors introduced during transmission and to also extract a clocking signal from the received signal.
[0007] Specifically, as shown in FIG. 2 , a transmitter 10 will encode a signal to be transmitted using an encoder 20 . The encoder allows information to be added to the signal that will enable the receiver to recover the original signal free from errors that may occur during transmission. There are several known encoding schemes of this nature, including Reed-Solomon, Turbo, and Bose, Ray-Chaudhri, Hocquenghem (BCH) encoding schemes. Other encoding schemes may exist as well. Reed-Solomon error correction, for example, operates by oversampling a polynomial constructed from the data to be transmitted. The polynomial is evaluated at several points, and these values are transmitted as signal S. Sampling the polynomial more often than is necessary makes the polynomial over-determined. As long as the receiver receives many of the points correctly, the receiver can recover the original polynomial even in the presence of a few bad points. Hence, the receiver 12 can use RS-8 error corrector 24 to recover the original polynomial used by encoder 20 and, hence, can recreate the original data that was used to create the polynomial free from any errors that may have occurred during transmission. Other error correction techniques may use different methods to enable the original data to be recovered at a receiver free from errors that may occur during transmission as is known in the art.
[0008] The transmitter/receiver pair shown in FIG. 2 is also configured to detect clock timing information from the incoming signal so that the receiver knows the frequency with which to read information from the physical medium. If the receiver is not operating at the same frequency as the transmitter, it may introduce errors into the received signal which is undesirable. Generally the receiver will use a Phase Locked Loop (PLL) or other similar structure to lock onto the transmission frequency being used by the transmitter 10 . Since PLLs and other synchronization circuits are well known in the art, the actual clock extraction portion has not been shown in FIG. 2 to avoid obfuscation of the other portions of the drawing.
[0009] In a system where the receiver relies on extracting the clocking frequency from the input signal, it is important for the input signal to not include a long string of zeros or a long string of ones, since this may cause the receiver to lose synchronization with the transmitter. Specifically, a long string of zeros or ones will be seen by the receiver as a constant voltage on the electrically conductive wire or as a constant light/dark signal on an optical fiber. A constant value does not have any transitions between states (e.g. high/low voltage or on/off light) which is what the PLL uses to determine the transmission frequency. Hence, a prolonged period without state transition does not provide the PLL or other synchronization circuit with information as to the frequency in use by the transmitter and can cause the receiver to lose synchronization with the transmitter.
[0010] Accordingly, to avoid transmission of long sequences of zeros or long sequences of ones, it is common for the transmitter to scramble the output signal (S), for example using a Linear Feedback Shift Register (LFSR) scrambler 22 . A linear feedback shift register is a shift register whose input bit is a linear function of its previous state. Fibonacci LFSRs and Galois LFSRs are two common implementations of LFSRs. The LFSRs may have a set number of places in the register, e.g. 16, and if properly designed will cycle through all possible values of the register to randomize the output such that the output from the scrambler f(S) is not likely to contain long strings of all zeros or all ones. As shown in FIG. 2 , the receiver will use the same scrambler 22 to unscramble the signal to remove the contribution from the scrambler prior to decoding the signal using error corrector 24 . As noted above, the error corrector will remove errors that may have occurred in the signal during transmission.
[0011] There are several sources of error that may contribute to corruption of the signal during transmission between the transmitter and receiver. For example, the signals may become weaker over time/distance. Likewise, external sources of noise may be added to the signal so that the signal received by the receiver may have other components in addition to the intended data output by the transmitter. The receiver is responsible for detecting the signal and making a decision, at the clocking frequency, as to whether the signal on the physical medium is a zero or a one. Typically, the receiver will use a threshold to make this decision—if the received signal is above the threshold the signal is interpreted as a one and, conversely, if the received signal is below the threshold the signal is interpreted as a zero. If the receiver does not implement this process correctly, the thresholding process at the receiver may likewise be a source of error. Accordingly, it would be desirable to be able to adjust the thresholding process at the receiver to improve the fidelity of signals received by the receiver on a communication network.
SUMMARY
[0012] The following Summary and the Abstract set forth at the end of this application are provided herein to introduce some concepts discussed in the Detailed Description below. The Summary and Abstract sections are not comprehensive and are not intended to delineate the scope of protectable subject matter which is set forth by the claims presented below.
[0013] A method and apparatus for adjusting a symbol decision threshold at a receiver in a communication network enables the receiver to be adapted to more correctly receive symbols as transmitted by a transmitter. In one embodiment, a received bit imbalance is detected by a receiver prior to error correction and after error correction to determine whether an error component of the received signal contains larger numbers of ones or larger numbers of zeros. Where the transmitter scrambles the signal prior to transmission, the receiver will also scramble the signal after error correction and prior to counting the number of zeros or ones. Any imbalance between the number of transmitted and received ones or zeros is used as feedback to adjust threshold values used by detectors to fine tune the manner in which the receiver interprets incoming signals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Aspects of the present invention are pointed out with particularity in the appended claims. The present invention is illustrated by way of example in the following drawings in which like references indicate similar elements. The following drawings disclose various embodiments of the present invention for purposes of illustration only and are not intended to limit the scope of the invention. For purposes of clarity, not every component may be labeled in every figure. In the figures:
[0015] FIGS. 1A-1C are functional block diagrams showing several transmitter/receiver pairs utilizing different physical transmission media;
[0016] FIG. 2 is a functional block diagram of a conventional transmitter/receiver pair;
[0017] FIG. 3 is a functional block diagram of a transmitter/receiver pair according to an embodiment of the invention;
[0018] FIG. 4 is a functional block diagram of an example physical interface utilizing received bit imbalance as feedback in adjusting decision threshold according to an embodiment of the invention;
[0019] FIG. 5 is a flow chart of a process of adjusting a symbol decision threshold at a receiver in a communication network according to an embodiment of the invention; and
[0020] FIGS. 6A-6C show an example waveform and the effect of threshold variation on symbol decision according to an embodiment of the invention.
DETAILED DESCRIPTION
[0021] FIG. 3 shows an example embodiment of a transmitter/receiver pair according to an embodiment of the invention. The transmitter, in this embodiment, is the same as the transmitter shown in FIG. 2 . However, the receiver is constructed differently to enable the receiver to determine the type of errors that occur during transmission and use this information to adjust thresholds of the receiver interface to balance the number of errors of each type (e.g. number of zero errors and number of one errors). By balancing the number of incorrect zeros that are received with the number of incorrect ones that are received, errors due to improper thresholding may be reduced to thereby tune the receiver to more correctly sense the received signal on the physical channel.
[0022] In FIG. 3 , the transmitter 10 includes a Reed-Solomon 8 encoder 20 to encode the signal to create signal S to be transmitted on optical fiber 14 . Other types of encoders may be used as well and the RS-8 encoder is illustrated as merely one example of a possible encoder that may be utilized by the transmitter. The encoder receives data to be transmitted and creates signal S to be transmitted on the communication network. The error corrector 24 at receiver 12 will remove errors from signal S. Likewise, although FIG. 3 has been illustrated to show an optical channel interconnecting the transmitter and receiver, other types of physical channels may be used as well and the invention is not limited to use with an optical embodiment. The transmitter 10 further includes scrambler 22 which may be implemented as a 16 bit LFSR scrambler or other type of scrambler. The scrambler creates a function f(S) of the signal S from error corrector 20 . In an embodiment where an optical signal is to be used to transmit data between the transmitter and receiver, the signals f(S) will be sent to an Electrical to Optical physical interface 26 where the electrical signals will be used to modulate a laser to enable corresponding optical signals to be created and output onto fiber 14 . Other types of physical interfaces would be used with other physical mediums.
[0023] The receiver 12 has a corresponding Optical to Electrical physical interface 28 , one embodiment of which is shown in FIG. 4 . FIG. 4 will be discussed in greater detail below. The O-E physical interface 28 creates electrical signals which includes the original signal transmitted by the transmitter f(S) plus an error component e. The error component e may include artifacts introduced by the transmission medium as well as artifacts introduced by the physical interface 26 and physical interface 28 . As described in greater detail below, according to an embodiment of the invention, an imbalance in the type of errors in the error component (e.g. false zeros and false ones) are detected and used to adjust thresholds of Optical to Electrical physical interface 28 to reduce the O-E interface's contribution to the amount of error included in signal f(S)+e.
[0024] As shown in FIG. 3 , the receiver 12 has some of the same components as a conventional receiver shown in FIG. 2 . Specifically, after the optical signals are converted to electrical signals, the signals are scrambled to recover the original signal. Since the signal includes an error component, the scrambler will also unscramble the error component of the signal to form signal S+f(e). This signal will then be passed to a error corrector 24 to remove the error component and recover the original signal S. In the illustrated embodiment a RS-8 error corrector is illustrated since that was the type of encoder utilized by the transmitter. The invention is not limited to use of a particular type of encoder/error corrector, as any type of error correction process may be utilized.
[0025] As shown in FIG. 3 , the receiver will also count the number of zeros or ones output by the Optical to Electrical physical interface 28 to determine how many symbols of a particular type are included in the signal f(S)+e. A 32 bit register or other sized register may be used to count the number of zeros or ones in the signal, or another structure may be used to count the number of zeros or ones.
[0026] To determine how many of the counted ones or zeros are attributable to the error component e, the receiver will recreate the scrambled signal f(S) and count the number of zeros or ones in the recreated scrambled signal f(S). Note that the signal output from the decoder in the transmitter is the same as the signal output from the encoder of the transmitter. Thus, the scrambled signal output from the scrambler 22 in the receiver will be the same as the scrambled signal output from the scrambler 22 of the transmitter 10 . Hence, the recreated scrambled signal 33 may be used to determine the composition of the error component. For example, as shown in FIG. 3 , the receiver can count the number of zeros or ones in the recreated scrambled signal 33 and subtract that count from the number of zeros or ones counted in the received signal f(S)+e. This will indicate if the error signal contains more ones than zeros, or more zeros than ones.
[0027] Note, in this regard, that where the receiver counts the number of ones contained in received signal f(S)+e then the receiver will likewise count the number of ones contained in the recreated signal f(S). Conversely, where the receiver counts the number of zeros contained in received signal f(S)+e then the receiver will likewise count the number of zeros contained in the recreated signal f(S).
[0028] By comparing the number of ones in signal f(S)+e with the number of ones in the original scrambled signal f(S), the receiver 12 can determine whether the error signal contains an imbalance in the number of zeros or an imbalance in the number of ones. Since it may be expected that noise-based errors would be evenly distributed between zero errors and one errors, then a detected imbalance in the number of zero errors or one errors may be inferred to be caused by an incorrect thresholding process in the O-E physical interface. Specifically, it may be inferred that the imbalance is likely to have been caused because the thresholds used by the Optical to Electrical interface to interpret the input signal from fiber 14 are incorrectly set.
[0029] For example, if at the line interface there are more “false ones” errors than “false zeros”, this would indicate that the O-E interface is incorrectly interpreting received signals as a one rather than a zero. Since the O-E interface compares the received signal against a threshold when making a decision as to whether the received signal is a one or a zero, an excess number of “false ones” would indicate that this threshold is too low and should be raised slightly. Likewise, if there are more “false zeros” than “false ones”, the O-E interface is incorrectly not detecting the incoming signals as a zero value. This would indicate that the threshold in use at the O-E interface is too high and should be lowered slightly.
[0030] The receiver may count both zeros and ones, or may count only one of these values. Where only one of the symbols is counted, the manner in which the threshold moves will depend on how the counted values are combined and the sign of the result. For example, if the system counts ones, and the number of ones in the signal f(S)+e is subtracted from the signal f(S), then a negative number would indicate an excess number of ones in the error signal. Conversely, if the system counts ones and the number of ones in the signal f(S) is subtracted from the number of ones in the signal f(S)+e, than an excess number of ones in the error signal would be shown as a positive number. Thus, the particular manner in which the symbols are counted and the manner in which the two numbers are combined will determine how the threshold should be adjusted.
[0031] FIG. 4 shows an example optical to electrical physical interface 28 to help further explain how this may occur. As shown in FIG. 4 , the O-E interface receives optical signals at input 40 and outputs electrical signals at output 42 . The O-E interface is binary, such that the signal on output 42 will either have a high voltage value (a one) or a low voltage value (a zero). In operation, the light from optical fiber 14 (optical signal 40 ) is input to a photodetector 44 which generates a current 46 . Different types of photodetectors have been developed, but in this example the photodetector outputs a current 46 which is proportionate to the amount of light input to the photodetector.
[0032] Current 46 is input to transimpedance amplifier 48 which converts the current to a voltage 50 . Voltage 50 is input to limiting amplifier 52 which will output either a high voltage or low voltage (a zero or one) on output 42 depending on whether the input voltage 50 is larger than a threshold 54 or smaller than threshold 54 . Other O-E physical interfaces may be used as well, and this interface is intended merely as an example interface that utilizes a threshold in connection with interpreting an incoming signal from a communication network. Other interfaces may be utilized as well depending on the particular implementation.
[0033] According to an embodiment, an imbalance 34 in the number of zero errors (or an imbalance in the number of one errors) is used to adjust threshold 54 . As noted above, if there are too many “one” errors, this indicates that the O-E physical interface is incorrectly interpreting the signal 40 as a one where it should have interpreted the signal 40 as a zero. Accordingly, the threshold 54 used by the O-E physical interface is too low and should be increased. Likewise, if there are too many “zero” errors, this indicates that the O-E physical interface is incorrectly interpreting the signal 40 as a zero where it should have interpreted the signal 40 as a one. This indicates that the threshold is too high and should be reduced.
[0034] FIGS. 6A-6C show an example waveform that may be received by a physical interface such as the optical-electrical physical interface 28 of FIG. 4 . FIGS. 6A-6C all show the same example waveform, but show different ways that the physical interface may interpret the waveform depending on the threshold. In FIG. 6A , the threshold is correct and the threshold level does not contribute to the error signal. In FIG. 6B , the threshold is too high. As noted in this diagram, if the threshold is too high the interface will occasionally incorrectly output a zero when it should have output a one. In this example, two zero errors have been circled where the high threshold caused two zero errors to occur. Likewise in FIG. 6C the threshold has been set to be too low. When the threshold is too low, the interface is more likely to output a one, and hence may occasionally incorrectly output a one when it should output a zero. In this example, three one errors have been circled where the low threshold caused the three one errors to occur.
[0035] According to an embodiment of the invention, by recreating the original signal f(S), the receiver is able to compare the original signal f(S) with the received signal f(S)+e to determine whether there is an imbalance of zeros or an imbalance of ones. This, then, may be used to adjust the threshold of the O-E physical interface.
[0036] FIG. 5 shows an example process that may be used according to an embodiment of the invention. As shown in FIG. 5 , when an input signal f(S)+e is received ( 100 ) the number of ones or zeros in the input signal will be counted ( 102 ). The input signal f(S)+e will then be scrambled ( 104 ) using the same scrambler that was used by a transmitter when transmitting the signal to create signal S+f(e). The descrambled signal will then be process ( 106 ) to remove any errors and recreate the original signal S transmitted by the transmitter.
[0037] The original signal S will then be scrambled ( 108 ) to create f(S). The receiver will count the number of ones or zeros in this scrambled signal f(S) ( 110 ). The number of ones in the scrambled signal f(S) will be compared with the number of ones in the input signal f(S)+e ( 112 ). Equivalently, the number of zeros in the scrambled signal f(S) may be compared with the number of zeros in the input signal f(S)+e. Any imbalance 34 in the number of ones (or zeros) in these two signals may be used to adjust a decision threshold 54 used by O-E physical interface 28 ( 114 ) to enable the O-E physical interface to be tuned to more reliably generate electrical signals from received optical signals.
[0038] Although an O-E physical interface has been used as an example thresholding interface, the techniques described herein may be used in other interfaces that utilize thresholds to make binary decisions related to received signals. For example, in a wireless context the wireless signals received on an antenna will be thresholded to determine whether the signal should be output as a zero or one. Accordingly, the invention is not limited to an embodiment in which an optical physical layer is being utilized, but rather embodiments of the invention may utilize these techniques in connection with receiving electrical signals and wireless signals as well.
[0039] The functions described above may be implemented as a set of program instructions that are stored in a computer readable memory and executed on one or more processors on the computer platform. However, it will be apparent to a skilled artisan that all logic described herein can be embodied using discrete components, integrated circuitry such as an Application Specific Integrated Circuit (ASIC), programmable logic used in conjunction with a programmable logic device such as a Field Programmable Gate Array (FPGA) or microprocessor, a state machine, or any other device including any combination thereof. Programmable logic can be fixed temporarily or permanently in a tangible medium such as a read-only memory chip, a computer memory, a disk, or other storage medium. All such embodiments are intended to fall within the scope of the present invention.
[0040] It should be understood that various changes and modifications of the embodiments shown in the drawings and described in the specification may be made within the spirit and scope of the present invention. Accordingly, it is intended that all matter contained in the above description and shown in the accompanying drawings be interpreted in an illustrative and not in a limiting sense. The invention is limited only as defined in the following claims and the equivalents thereto. | A method and apparatus for adjusting a symbol decision threshold at a receiver in a communication network enables the receiver to be adapted to more correctly receive symbols as transmitted by a transmitter. In one embodiment, a received bit imbalance is detected by a receiver prior to error correction and after error correction to determine whether an error component of the received signal contains larger numbers of ones or larger numbers of zeros. Where the transmitter scrambles the signal prior to transmission, the receiver will also scramble the signal after error correction and prior to counting the number of zeros or ones. Any imbalance between the number of transmitted and received ones or zeros is used as feedback to adjust threshold values used by detectors to fine tune the manner in which the receiver interprets incoming signals. | 7 |
BACKGROUND OF THE INVENTION
This invention relates generally to large door structures and appurtenances, and more specifically to a large overhead opening door apparatus with suspension structure, combination manual and automatic powered opening mechanism and lock mechanism for buildings constructed to conform to sloping terrain.
Large overhead opening doors have been in use for some time in large building structures wherein opening a space of substantial size is necessary to allow entry and exit of large objects. A typical application for such large doors is in airport hangars wherein the door space must be large enough to accomodate entry and exit of aircraft. Since the doors are quite large, an ever pervading problem involves opening and closing the doors. This problem is compounded if the building is built on terrain that is not level and with a floor that conforms to such terrain, which is often ecomonically feasible especially for relatively long buildings such as hangars which would require a considerable amount of excavation and fill to provide a level floor, not to mention the otherwise required artificial grading of the surrounding parking aprons and approaches to the hangar. It is also desirable to have a suitable locking mechanism to prevent the large doors from being opened by unauthorized personnel or adverse wind conditions. The present invention provides door apparatus for aircraft hangars which are built with structures and floors that conform to sloping terrain on which they are built and which can be readily opened and closed both manually and automatically and which can be locked in the closed position when not in use.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a large door apparatus which can be suspended from an overhead structure of a building which is not level, yet which can be opened and closed by raising and lowering respectively without binding.
Another object of the present invention is to provide a large door with two sections hinged together for folding up when the door is opened, the top of the door being pivotally attached to the building structure and the bottom of the door being confined to travel in a vertically straight plane, and hinged connection of the two sections to each other near the center of the door, the two sections beind pivotally movable outwardly and upwardly to an open position wherein the top and bottom sections are folded toward each other.
Yet another object of the present invention is to provide a lock mechanism which prevents the hinged seam between the two sections of the door from moving outwardly and thereby locking the door in the closed position.
A further object of the present invention is to provide a combination door opening apparatus which can be operated manually or alternatively which can be power operated automatically.
This invention comprises a door structure, closing and opening means, and locking means for installation and use in a building which has a floor and overhead structure conforming to ground terrain that is not level. The lateral sides of the building include vertical columns of approximately equal length extending upwardly from the ground for supporting the overhead structure and roof of the building. The overhead structure of the building is attached on the top of each column respectively, therefore, the overhead structure of the building which spans the distance between each column is not level and does not form a right angle with the respective columns. Consequently, the openings in the building, which is defined by a pair of spaced-apart vertical columns on each side, the floor of the building on the bottom, and the spanning overhead structure on the top, is not rectangular, but rather it is a parallelogram. This invention provides an apparatus whereby a door which opens by folding upwardly can be suspended from the sloping overhead structure to open and close in a parallelogram-shaped doorway without binding either within the structure of the door itself or with the columns on either side of the doorway.
Opening means is provided to lift and cause the bottom edge of the lower section of the door to move upwardly in a vertical plane while the top and bottom sections pivot outwardly with respect to the building. The lift means can be easily operated manually or alternatively with a motor without any requirement of connecting or disconnecting either the manual or the power drive. Since the top of the upper section and the bottom of the lower section are confined within the same vertical plane, any upward movement of the lower section must be accompanied by laterally outward movement of the hinged seam between the upper and lower sections of the door. Since the lift means applies a force to the bottom of the lower section of the door directed substantially in a vertical direction, bias means are also provided to initially urge the hinged seam between the upper and lower sections in a laterally outward direction to prevent damage to the door or lifting mechanism when the initial vertical lifting force is applied by the lift means. A strong, durable, locking mechanism is also provided which prevents laterally outward movement of the hinged seam and thereby locks the door to prevent opening.
DESCRIPTION OF THE DRAWINGS
Other objects, advantages and capabilities of the present invention will become more apparent as the description proceeds, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of the side of an aircraft hanger which is built with a floor and overhead structure that conforms to the underlying ground that is not level, and also showing the large doors which are the subject of this invention;
FIG. 2 is a view of one of the large doors taken from the inside of the hanger and showing the trapeziodal shape of the opening (perhaps somewhat exaggerated to better illustrate the concept of the invention);
FIG. 3 is a perspective view which shows portions of adjacent overhead trusses which span the door openings illustrating the connection of the trusses to a vertical column;
FIG. 4 is an end view of the chair used to connect the truss to the column;
FIG. 5 is a side view taken from the inside of the building of the chair shown in FIG. 4;
FIG. 6 is an elevation side view of the building structure showing the columns, the overhead structure, the door in closed position, the door opening mechanism, and the door in opened position being shown in phantom lines;
FIG. 7 is a plan view showing the connection of overhead girders to a column;
FIG. 8 is a perspective view of an end portion of a door in closed position taken from the inside of the building showing the guide wheel and locking mechanism in relation to the column;
FIG. 9 is a sectional fragmentary view of the door taken along lines 9--9 of FIG. 2, illustrating the means for hanging the door, and the means for lifting the door, including the hinged seam between the upper and lower sections with the cable activated bias means;
FIG. 10 shows an alternative embodiment of the hinged seam of the door wherein the biased means is induced by prestressing the hinged joint;
FIG. 11 illustrates still another embodiment of bias means in the hinged seam joint of the door with a spacer plate in the opening side of the seam;
FIG. 12 is an elevational view of the back of the lift mechanism;
FIG. 13 is a side elevation in section of the door lifting means taken along the line 13--13 of FIG. 12 as shown from the opposite of that illustrated in FIG. 6;
FIG. 14 is an elevation view of the front of the lift mechanism.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A building in the form of a hangar H with large overhead folding doors 10 to provide access for shelter and repairs for airplane A, as illustrated in FIG. 1, embodies the door suspension structure, opening and closing apparatus, and locking means of the present invention. The door structure and opening and closing apparatus of the present invention is particularly appropriate for use in such a hangar H which is constructed on ground G that is relatively uniform but not level and with a floor 12 that conforms to the terrain of ground G.
The large overhead doors basically include an upper section 40 with a metal or fiberglass skin 41 and a lower section 50 with a metal or fiberglass skin 51. As will be discussed below in more detail, the upper section 40 is hinged to the overhead structure of the hangar H, and lower section 50 is attached by hinges to the upper section 40. A tapered rubber shoe or spacer 80 is affixed to the bottom of the lower section 50 to conform to the sloping floor 12 for a weather-tight seal.
The structure of the door 10 and the structural portion of the hangar H which forms the door opening is shown in FIG. 2. The door opening is defined on the sides by the space between the two vertical structural columns 14 of the hangar H, on the top by the overhead truss 16, and on the bottom by the concrete floor 12. As can be seen in FIG. 2, perhaps somewhat exaggerated for illustrative purposes, the concrete or asphalt floor 12 is not level but conforms to the terrain of ground G. The columns 14 extend vertically in equal distances above the floor 12, and the overhead truss 16, which is supported on each end by the respective columns 14, slopes at the same angle as the floor 12. Consequently, the door opening is slightly parallelogram in shape.
The door 10 is of rectangular configuration and is comprised of an upper section 40 pivotally attached by hinges 62 to a lower section 50. The upper section 40 includes an upper horizontal beam 42, a lower horizontal beam 44, vertical studs 46, and diagonal braces 48. Likewise, the lower section 50 includes an upper horizontal beam 52, a lower horizontal beam 54, vertical studs 56, and diagonal braces 58. The lower section 50, being somewhat larger than the upper section 40, also includes an intermediate horizontal beam 53 and diagonal corner braces 59.
The door 10 illustrated in FIG. 2 is in closed position. When it is opened, the lower section 50 is folded or pivoted on hinges 62 toward the upper section 40 so that in full open position, both the upper and lower sections 40 and 50 approach substantially horizontal orientation near the overhead structure of the hanger H as illustrated in FIG. 1 by the designation 10'. This full open position is also shown in phantom lines 10' in the elevational view of FIG. 6. The door 10 is raised or opened by lifting vertically on the lower horizontal beam 54 of the lower section 50. When such a lifting force is applied, the lower edge or beam 54 of the lower section 50 moves vertically upward in a vertical plane between the columns 14 while the upper edge or beam 42 of the upper section 40 pivots in relation to the overhead truss 16 allowing the lower edge or beam 44 of upper section 40 and the upper edge or beam 52 of lower section 50 to move in an arcuate path upwardly and outwardly to the open positions shown in FIGS. 1 and 6.
It can be appreciated that if the door was also shaped in a parallelogram configuration conforming to the door opening or if a rectangular door was mounted on a slant to conform to the sloping floor 12 and the overhead truss 16, the relative movement of the door sections to the structural members of the hangar H would result in excessive binding or wedging of the respective parts and would therefore not operate satisfactorily. Consequently, even though the hangar H structure conforms to the contour of the ground G, the door 10 must still be oriented and hung from the overhead structure along a horizontal line so that it can be lifted vertically upward between the vertical columns 14 without excessive binding or wedging. It is a significant feature of this invention to provide a truss system which can be oriented on a slant between two vertical columns 14, yet which can accomodate the pivotal attachment of the upper edge or beam 42 of a door 10 along a horizontal line. To accomplish this purpose, a truss 16 with an upper gently sloping member 18, a lower gently sloping member 20, upright members 22 and diagonal members 24, is supported by chairs 30 between two vertical columns 14 as best seen in FIGS. 2-5. The upper and lower members 18, 20 are oriented substantially parallel to the sloping floor 12 of the building. Each chair 30 includes a web 34 extending upwardly from a base plate 32. The chair 30 supports the end of the upper member 18 of truss 16, and is mounted on a bearing plate 36 on top of column 14 and secured by bolts 38. In this manner the truss 16 is supported at each end near the top of the respective columns 14 with the end upright members 22 of each truss 16 being adjacent but unattached to the respective columns 14 in such a manner that the truss 16, when oriented parallel to the floor 12 of the hangar H is at either a slight acute or obtuse angle, depending on the slope, to the respective columns 14.
A fairly wide face plate 26 is affixed to the top of the truss 16 immediately under the upper member 18, e.g., by welding, to provide a surface on which the upper edge or beam 42 of the door 10 can be attached in a horizontal line in spite of the overall sloped orientation of the truss 16.
The upper edge or beam 42 of the door 10 is shown in FIG. 2 in phantom lines attached in a horizontal orientation to the mounting plate 26 by hinges 60. As can best be seen in FIG. 9, the door 10 is hung from the truss 16 by a 90-degree hinge 60, one leg of which is affixed to the mounting plate 26, the other leg of which is affixed to the upper beam 42 of the door 10, whereby the upper section 40 of the door 10 can be pivoted around hinge 60 outwardly in relation to the truss 16.
FIG. 9 also shows in cross-section the pivotal attachment of the upper section 40 of the door 10 to the lower section 50, as well as the attachment of the lift cable 72 to the door 10. The upper section 40 is provided with an interfacing channel member 64 affixed to the lower horizontal beam 44 with the open side of the channel 64 facing downward. The lower section 50 is also provided with a similar interfacing channel 66 affixed the upper horizontal beam 52 with its open side facing upwardly in communication with the downwardly facing side of the intefacing channel 64 on the upper section 40 of the door 10. The inside edges of the respective interfacing channels 64, 66 are pivotally attached together by hinges 62 such that the outside edges of the respective interfacing channels, 64, 66 will separate as the upper and lower sections 40 and 50, respectively are pivoted toward one another when the door is raised or opened as shown in phantom lines in FIG. 6.
Also shown in FIG. 9, is a footing channel 74 affixed beneath the lower horizontal beam 54 of the lower section 50. A lift cable 72 as trained over a fairlead sheave 78 which is attached to the overhead truss 16 in spaced relation to the inside of the door 10, the cable descending along the door and attached at its lower end to the footing channel 74 by a lift bracket 75 and shackle 76. Near the top of the door 10 the cable passes over the fairlead sheave 78 which is attached to truss 16 by yoke 79, and from there extends substantially horizontally toward lifting means generally designated 125 where it is attached to a roller chain 110 as will be hereinafter described in more detail.
A straight vertical force was applied to the bottom of the door 10 when it is in the down or closed position it would only result initially in a force which tends to squeeze the intefacing channels 64, 66 together but would have no horizontal component of force to urge the hinged seam comprised of the lower edge 44 of upper section 40 and the upper edge 52 of lower section 50 outwardly. Consequently, a straight vertical lifting force on the lift cable 72 could result in damage to the door or to the lifting means. To alleviate this potential damage, a strut 70 can be attached to the lower section 50 of the door 10 extending inwardly into contact with the lift cable 72. The strut 70 extends inwardly far enough to distort the lift cable 72 out of a straight line between the shackle 76 and fairlead sheave 78. Consequently, when a vertical lift force is applied, the cable 72 will also exert a horizontal force component on the lower section 50 through strut 70, resulting in an initial urging of the hinged seam outwardly at the start of the lifting operation. Once the initial outward urging is accomplished, continued vertical force applied to the bottom of the door 10 through lift cable 72 results in the pivotal movement of the door sections as described above to the open position.
An alternative initial bias means for starting the pivotal movement of the upper and lower sections 40 and 50 in relation to each other is illustrated in FIG. 10, wherein the inside edges of the interfacing channels 64, 66 are prestressed, such as with a C-clamp C shown in phantom lines, while the hinges 62 are being attached. Once the hinges 62 are attached, the C-clamp C can be removed, and the prestressed condition will urge the respective interfacing channels 64, 66 in a direction to spread their respective outer edges apart from each other. Consequently, when a vertical lifting force is initially applied to the bottom of the door, the upper and lower sections 40 and 50, respectively, will easily pivot around hinges 62 in relation to one another toward the open position.
Still another alternative bias means for accomplishing this initial pivoting relation between the upper and lower sections of the door is illustrated in FIG. 11, wherein a spacer strap 68 is sandwiched between the respective outer edges of interfacing channels 64, 66. This spacer 68 also serves the function of providing an initial bias tending to pivot the upper and lower sections 40 and 50 around hinge 62 with respect to each other when the initial vertical lifting force is applied to the bottom of door 10.
Guide rollers 100 extend from the lower corners of the door into engagement with channels in the wide flange steel columns 14, as best seen in FIG. 8, to maintain non-binding upward movement of the lower edge of the door in a vertical plane between the columns 14. Each roller 100 is mounted on an axle 102 and supported by front and rear plates 104, 106, respectively, on the footing channel 74.
A locking device is also shown in FIG. 8 which is comprised of a lock cable 108 attached at its upper end to the vertical end member 22 of upper section 40, and which is attached at its lower end to a tightener apparatus affixed to the vertical end member 56 of lower section 50. The mid-section of the cable 108 is passed over a shaft 84 supported in inwardly spaced relation to the door by a U-shaped bracket 82 attached to the column 14. Consequently, when the lock cable 108 is tightened over the shaft 84, it exerts an inwardly directed lateral force on the door which counteracts the initial bias force placed on the interfacing channel 64, 66, as discussed above, and thereby prevents the door from being opened. A keeper 86 is also provided on the face end of shaft 84 to prevent the lock cable 108 from slipping off the shaft 84.
The tightener is comprised of a yoke 88 with a right leg 90 and a left leg 92 extending from a plate 89 which is mounted on vertical member 56 of the lower section 50 of door 10. A shackle 93 with two-spaced apart arms 94,96 is pivotally mounted between the legs 90, 92 of the yoke 88. A cross pin 98 extends between and connects the arms 94, 96 at a spaced distance outwardly from their pivotal connection with the yoke 88. This cross pin 98 serves as the anchor on which the lower end of the lock cable 108 is attached to the shackle 93. The arms 96 also has an elongated extension to serve as a handle for the shackle 93 of the lock mechanism. Thus, when the shackle 93 is rotated downwardly and toward the door, the pin 98 applies a tension force to the cable 108 tightening the cable over the shaft 84 of bracket 82 to resist any outward pivotal movement of the upper and lower sections 40, 50 of the door 10 thereby preventing opening. It can also be appreciated that the specific spaced relation of the parts on the cable tightener, including the length of the extending legs 90, 92 of yoke 88, the point of pivotal attachment of the arms 94, 96 of schakle 93 to the yoke 88 and the location of the pin 98, when the handle 96 is rotated the full distance downwardly and toward the door, an "over-the-center" bias is maintained on the shackle 93 to retain the lock cable 108 in tensioned condition. When the handle 96 is rotated outwardly and upwardly, however, the tension on the lock cable 108 is released, and the door 10 is allowed to open.
As also described above, the door 10 is opened by an upwardly directed force on the lift cable 72. Another significant feature of this invention is the lift means 125 for applying the lifting force on the lift cable 72. Of course, it is usually advantageous to provide a power lift means for convenience; however, it is also frequently necessary to have a manual lift means available for use in opening the door, for example, when there is a disruption in the available power source, or when the power lift means is in need of repair. Consequently, this invention includes a combination power and manual lift means utulizing common components for ecomony, yet either of which can be selectively operated without interferring or requiring disconnection of the other.
A sectional elevational view of the hangar H structure is shown in FIG. 6, including floor 12, outside columns 14, inside columns 15, girders 124 supported on their outer ends by gusset plate 28 attached to column 14 and on their inner ends by the bearing plate 29 at the top of column 15. A roof 13 is also shown supported over girders 124 by perlins 127. The lift means 125 is suspended under a girder 124, as best seen in FIGS. 6, 12, 13 and 14.
Since as access door for hangars of the size indicated in this description is relative heavy, the lift means includes a cog-like roller chain 110 attached at one end to the lift cable 72 with its opposite end trained over and positively internesting with teeth 113 on a sprocket 114; and a counterweight 112 is suspended from said opposite end of said roller chain. The counterweight 112 has sufficient weight to apply a force to the lift cable of approximate magnitude equal to that required to maintain the door 10 in a stable, non-moving position. Consequently, in order to raise or open the door, a sufficient increment of additional force must be applied to the lift cable 72 by either power or manual means to overcome the momentum and frictional forces of the door. The counterweight is however of sufficient weight to hold the door in any position including and between the positions of fully open and fully closed.
The manual lift mechanism, as best viewed in FIGS. 6, 12 and 13, includes an endless coil or pull chain 142 trained over and engaged with mating sheave 140 which is connected to a rotatable shaft 116 journaled within a bearing housing 118. The sprocket 114 located within the bearing housing 118 is also attached to the rotatable shaft 116 such that rotation of the sheave 140 causes the sprocket 114 to rotate and drive the roller chain with its teeth 113 in either direction. Consequently, when sufficient manual force is applied to the chain 142 to provide that additional increment of force on the lift cable 72 necessary to open the door, the sheave 140 will rotate causing the shaft 116 and sprocket 114 to rotate and to pull the lift cable 72 upwardly to open the door 10. A safety latch, such as a slotted angle iron, can be affixed to the cage 146 for releasably securing the coil chain 146 against movement, thus restraining movement of the door 10 at any desired position.
The bearing housing 118 includes a front side 120, with a hole 138 through which roller chain 110 enters the bearing housing 118, a rear side 122, internal bearing supports 130, 132 with bearings 126, 128, respectively, on opposite sides of sprocket 114 for supporting shaft 116, an end plate 134, and an end bearing 136 for supporting the end of shaft 116 on which the sheave 140 is mounted. The coil chain 142 is endless and is of sufficient length to hang near the floor 12 of the hangar H so that it can be conveniently reached and grasped by a person standing on the floor. Chain guides 144, 145 extend from the bearing housing 118 into radially spaced relation to the sheave 140 on either side of the coil chain 142 to prevent the coil chain 142 from disengaging or jumping off of sheave 140. The counterweight 112 which is suspended from lower chain 110 as described above, moves from a position in proximity to the bearing housing 118 as illustrated in FIG. 6 when the door is closed to a position near the floor 112 as indicated in phantom lines 112' when the door is fully opened as indicated in phantom lines 10'. A cage 146 is provided to guide the counterweight 112 in a vertical line between its upper and lower positions and to provide a safety barrier to prevent persons from inadvertantly walking or standing beneath the counterweight when it is descending as the door is being opened.
A power-assist mechanism is also provided as an alternative to applying manual force to raise or open the door 10. The power-assist mechanism essentially includes an electric motor 148 with a drive sprocket 160 attached on its drive shaft 149. The electric motor is pivotally mounted on the front side 120 of the bearing housing 118 such that the weight of the motor 148 urges the drive sprocket 160 into engagement with the roller chain 110. Consequently, the motor can also apply a sufficient incremental force to the lower chain 110 in addition to the force applied by the counterweight 112 to open the door 10. Of course, running the motor in a reverse direction results in closing the door. Manual operation of the door as described above while the motor is de-activated results in the roller chain 110 merely causing the armature of the motor 148 to rotate, but this rotation does not materially interfere with the manual operation of the door lift means.
The motor mount includes a frame 151 comprised of a pair of parallel, spaced-apart angle irons, each of which is pivotally attached by pin 154 to an ear 152 extending from the front side 120 of the bearing housing 118. A mounting plate 150 extends between the angle irons of frame 151 and provides a surface on which the motor is secured. A roller chain guide 158 is supported in close radially spaced relation under the peripheral surface of the drive sprocket 160 by a leg 156 rigidly attached to the side of the motor mount. The space between the guide 158 and the drive sprocket 160 is sufficient to accomodate the passage of the roller chain therebetween, but is close enough to prevent the roller chain 110 from becoming disengaged from the drive sprocket 160. Even though the weight of the motor acting downward through the drive sprocket 160 on the roller chain 110 provides the primary engaging force, as described above, the guide 158 prevents the teeth of the sprocket 160 from jumping or slipping alternately in and out of engagement with the lower chain.
Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof. | A structure for mounting and apparatus for opening, closing, and locking a large, overhead door is adapted for buildings constructed on terrain which is not level and having floor and overhead structures that conform to the terrain. A sloping overhead truss spans a door opening and includes a widened faceplate along the length of its span to accommodate mounting a large overhead opening door along a horizontal line between vertical columns. A combination manual and automatic electrically powered door opening apparatus includes a counterweight, a coil chain and sheave for manual operation which is interchangeable with an electrically powered motor for automatic operation, all connected to a common lift cable which applies substantially vertical lifting force to the lower edge of the door for opening. Bias means for causing initial folding of door sections for opening, and locking apparatus for resisting folding of the door sections to prevent opening are also provided. | 4 |
[0001] This application is a continuation-in-part of co-pending application Ser. No. 10/001,737, filed Oct. 25, 2001 and claims priority therefrom.
FIELD OF THE INVENTION
[0002] The invention relates to hydrocracking, and more particularly to hydrocracking occurring in more than one stage.
BACKGROUND OF THE INVENTION
[0003] In the refining of crude oil, vacuum gas oil hydrotreaters and hydrocrackers are employed to remove impurities such as sulfur, nitrogen and metals from the feed. Typically, the middle distillate boiling material (boiling in the range from 250° F.-735° F.) from VGO hydrotreating or moderate severity hydrocrackers does not meet the smoke point, the cetane number or the aromatic specification required.
[0004] Removal of these impurities in subsequent hydroprocessing stages (often known as upgrading), creates more valuable middle distillate products. Hydroprocessing technology (which encompasses hydrotreating, hydrocracking and hydrodewaxing processes) aims to increase the value of the crude oil by fundamentally rearranging molecules. The end products are also made more environmentally friendly.
[0005] In most cases, this middle distillate is separately upgraded by a middle distillate hydrotreater or, alternatively, the middle distillate is blended into the general fuel oil pool or used as home heating oil. Recently hydroprocessing schemes have been developed which permit the middle distillate to be hydrotreated in the same high pressure loop as the vacuum gas oil hydrotreating reactor or the moderate severity hydrocracking reactor. The investment cost saving and/or utilities saving are significant since a separate middle distillate hydrotreater is not required.
[0006] There are several U.S. patent publications which are directed to multistage hydroprocessing within a single high pressure hydrogen loop. In U.S. Patent Application 20030111386, high conversion of heavy gas oils and the production of high quality middle distillate products is possible in a single high-pressure loop with reaction stages operating at different pressure and conversion levels. The flexibility offered is great and allows the refiner to avoid decrease in product quality while at the same time minimizing capital cost. Feeds with varying boiling ranges are introduced at different sections of the process, thereby minimizing the consumption of hydrogen and reducing capital investment.
[0007] U.S. Patent Application 2003111387 also discloses multi-stage hydroprocessing for the production of middle distillates. A major benefit of this invention is the potential for simultaneously upgrading difficult cracked stocks such as Light Cycle Oil, Light Coker Gas Oil and Visbroken Gas Oil or Straight-Run Atmospheric Gas Oils utilizing the high-pressure environment required for mild hydrocracking.
SUMMARY OF THE INVENTION
[0008] This invention, as are those discussed in the Background, is directed to processes for upgrading the fraction boiling in the middle distillate range which is obtained from VGO hydrotreaters and moderate severity hydrocrackers. This invention preferably involves a multiple stage process employing a single hydrogen loop. It could, however, be used in any fixed bed hydroprocessing scheme such as mild hydrocracking, conventional single stage or two stage hydrocracking and hydrotreating applications.
[0009] In this invention, removing distillate products as they are formed helps to improve the environment of the cracking reactions by more effective utilization of the reactor space, hydrogen and catalyst. Improved selectivity for distillates results, providing the yield of low per pass conversion, but without recycling large quantities of recycle oil.
[0010] The investment cost saving, as well as utilities savings, are significant since the hydrocracking reactor could be potentially taken out of a conventional recycle gas loop. Less catalyst volume and less hydrogen are required in the hydrocracking reactor as well. This invention may be employed in a reactor having multiple catalyst beds, or in a scheme employing several small, single bed reactors in series. Improved catalyst kinetics and activity also result from this invention.
[0011] The hydroprocessing method of the instant invention, which has at least two reaction stages, comprises the following steps:
(a) passing a hydrocarbon feed into a first reaction stage which is maintained at hydroprocessing conditions, where it is contacted with a catalyst in at least one fixed bed and at least a portion of the feed is converted; (b) passing the effluent of step (a) to a hot high pressure separation zone; (c) separating the stream of step (b) into an unconverted liquid effluent and a stream comprising converted products having boiling points below that of the feed, said products being subsequently passed to fractionation; (d) passing the unconverted liquid effluent from step (c) to a second reaction stage, said stage comprising a plurality of reaction zones, wherein each zone is maintained at hydrocracking conditions and separation occurs between each zone; (e) contacting the feed in the first reaction zone of step (d) with a catalyst in a fixed bed, thereby converting at least a portion of the feed; (f) separating the effluent of step (e) into an unconverted liquid effluent, and a hydrogen-rich converted stream; (g) passing the unconverted liquid effluent from step (f) to a second reaction zone of the second stage, the zone being maintained at hydrocracking conditions; (h) contacting the feed in the second reaction zone of step (g) with a catalyst in a fixed bed, thereby converting at least a portion of the feed; (i) fractionating the effluent of step (h) to produce one or more middle distillate product streams.
BRIEF DESCRIPTION OF THE FIGURE
[0021] The Figure illustrates a schematic flow diagram of the instant invention. It is a schematic of a two-stage hydrocracker. The second stage possesses at least two reaction zones.
DETAILED DESCRIPTION OF THE INVENTION
Description Of The Preferred Embodiment
[0022] The FIGURE illustrates the preferred embodiment of the invention. The oil feed in line 1 is preheated, and pumped up to the first stage hydrotreating reactor pressure by the first stage feed pump (not shown). Oil feed in line 1 is combined with preheated recycle gas (line 2 ) to form line 3 . Line 3 is further heated by process heat exchange (not shown). Line 3 is also heated in the first stage feed furnace 5 .
[0023] The combined feed is sent to the first stage hydrotreating reactor 10 . In this reactor, the feed is hydrotreated and partially hydrocracked. Hydrogen recycle gas (line 4 ) is used to quench the reaction exothermic heat release. The effluent from this reactor, line 6 , is composed of H 2 S, NH 3 , light gases, naphtha, middle distillate and hydrotreated heavy gas oil.
[0024] This first stage reactor effluent 6 is then cooled by preheating feed and/or steam generation (exchanger bank 25 ) and routed to a Hot High Pressure Separator (HHPS) 30 situated between the first stage hydrotreating reactor and the second stage hydrocracking reactor In HHPS, most of the 700-material is removed through line 8 and sent to hydrogen recovery and product fractionation. Material in line 8 is cooled (by steam generation or process heat exchange) and sent to a Cold High Pressure Separator (not shown) on its way to the recycle gas compressor.
[0025] HHPS is operated at a slightly lower pressure than the first stage hydrotreating reactor. HHPS bottoms, line 7 , mainly composed of unconverted oil, is let-down under pressure (valve 35 ), combined with line 12 , mixed with fresh makeup hydrogen (line 13 ) and routed to the inlet of the second stage hydrotreating or hydrocracking reactor 20 . Line 12 is composed of recycle oil from fractionation (line 9 ) and fresh aromatic feed oil (line 11 ).
[0026] The liquid from the top bed ( 20 a ) of this hydrotreating or hydrocracking reactor is taken but (line 16 ) and flashed in a side vessel 40 . Distillate products are removed overhead via line 17 . The liquid from this side vessel 40 is removed via line 18 and is cooled in an indirect heat exchanger 45 heating a process stream-and put back to the bed below ( 20 b ) after added adequate fresh makeup hydrogen (line 23 ). This set is repeated for the subsequent beds in the hydrocracking reactor, with the effluent of bed 20 b (line 19 ) being taken out and flashed in a side vessel 50 . Distillate products are removed overhead via line 21 . The liquid from this side vessel 50 is removed via line 22 and is cooled in an indirect heat exchanger 55 heating a process stream and put back to the bed below ( 20 c ) under its own pressure by gravity flow after added adequate fresh makeup hydrogen (line 26 ). The final liquid product is removed via line 23 .
[0027] The total fresh makeup hydrogen for the plant is routed through the second stage hydrocracking reactor and the excess hydrogen arrives back in the recycle gas loop at the recycle gas compressor suction to satisfy the needs of first stage reactor.
[0028] The concept of removing products as they are formed results in better utilization of the given second stage hydrocracking reactor catalyst volume by incrementally increasing the true residence time available for the still unconverted oil and by delivering shots of high purity hydrogen to where specifically needed in the liquid phase. This further gives an incremental kinetics boost and results in higher per pass conversion. This gives the direct benefit of less recycle liquid from fractionator bottoms to achieve desired target conversion.
[0029] A customized hydrocracking catalyst system in an ascending/descending temperature profile would be used in the second stage reactor using relatively mild hydrocracking catalyst at the top beds and progressively higher activity stable (zeolitic) hydrocracking catalysts in subsequent beds.
[0030] Converted material from the Cold High Pressure Separator, side vessels, and reactor effluents from subsequent stages could be combined or kept separate and sent to product distillation and recovery. Or the second stage effluent could be post-treated by adding catalyst in the side vessels or in a downstream, low pressure, cleaner environment post-treat step.
[0031] The product distillation (not shown) could be a combined unit operation for the first stage hydrotreating reactor and second stage hydrocracking reactor products or could be a divided unit operation (within one shell) for separate distillation of first stage hydrotreating reactor and second stage hydrocracking reactor products.
[0032] In either step, the HHPS bottoms liquid would be cooled only to around 650 F (or desired second stage hydrocracking reactor inlet temperature) and using a hot high differential pressure pump directly sent to the second stage inlet without the need for an intermediate cooling/heating train or storage or a furnace. If required, any startup heating requirement of the second stage hydrocracking reactor could be combined with the first stage hydrotreating reactor feed furnace.
[0033] Feeds
[0034] A wide variety of hydrocarbon feeds may be used in the instant invention. Typical feedstocks include any heavy or synthetic oil fraction or process stream having a boiling point above 392 F (200 C). Feeds to this invention generally include hydrocarbons boiling in the range form 500 F to 1500 F. Such feedstocks include vacuum gas oils, demetallized oils, deasphalted oil, Fischer-Tropsch streams, FCC and coker distillate streams, heavy crude fractions, etc. Other streams include heavy atmospheric gas oil, delayed coker gas oils, visbreaker gas oils, aromatic extracts, heavy residue thermal or catalyst upgrader gas oils, and thermal or catalyst fluid cracker cycle oils. Typical feedstocks contain from 100-5000 ppm nitrogen and from 0.2-5 wt. % sulfur.
[0035] The recycle oil (from the product distillation) can be introduced at the second stage hydrocracking inlet or at a suitable bed.
[0036] Products
[0037] The hydrocracking process of this invention is especially useful in the production of middle distillate fractions boiling in the range of about 250-700 F (121-371 C). A middle distillate fraction is defined as having a boiling range from about 250 to 700 F. The term “middle distillate” includes the diesel, jet fuel and kerosene boiling range fractions. The kerosene or jet fuel boiling point range refers to the range between 280 and 525 F (138-274 C). The term “diesel boiling range” refers to hydrocarbons boiling in the range from 250 to 700 F (121-371 C). Gasoline or naphtha normally boils in the range below 400 (204 C). Boiling ranges of various product fractions recovered in any particular refinery will vary with such factors as the characteristics of the crude oil source, local refinery markets and product prices.
[0038] Conditions
[0039] Hydroprocessing conditions is a general term which refers primarily in this application to hydrocracking or hydrotreating, preferably hydrocracking.
[0040] Hydrotreating conditions include a reaction temperature between 400 F-900 F (204)C-482 C), preferably 650 F-850 F (343 C -454 C); a pressure between 500 to 5000 psig (pounds per square inch gauge) (3.5-34.6 MPa), preferably 1000 to 3000 psig (7.0-20.8 MPa); a feed rate (LHSV) of 0.5 hr (−1) to 20 hr (−1) (v/v); and overall hydrogen consumption 300 to 2000 scf per barrel of liquid hydrocarbon feed (53.4-356 m (3)/m (3)feed).
[0041] Typical hydrocracking conditions include a reaction temperature of from 400 F-950 F (204 C-510 C), preferably 650 F-850 F (343 C-454 C). Reaction pressure ranges from 500 to 5000 psig (3.5-34.5 MPa), preferably 1500-3500 psig (10.4-24.2 MPa). LHSV ranges from 0.1 to 15 hr (−1)(v/v), preferably 0.25-2.5 hr (−1). Hydrogen consumption ranges from 500 to 2500 scf per barrel of liquid hydrocarbon feed (89.1445 m (3)H (2)/m (3)feed).
[0042] Catalyst
[0043] A hydroprocessing zone may contain only one catalyst, or several catalysts in combination.
[0044] The hydrocracking catalyst generally comprises a cracking component, a hydrogenation component and a binder. Such catalysts are well known in the art. The cracking component may include an amorphous silica/alumina phase and/or a zeolite, such as a Y-type or USY zeolite. Catalysts having high cracking activity often employ REX, REY and USY zeolites. The binder is generally silica or alumina. The hydrogenation component will be a Group VI, Group VII, or Group VIII metal or oxides or sulfides thereof, preferably one or more of molybdenum, tungsten, cobalt, or nickel, or the sulfides or oxides thereof. If present in the catalyst, these hydrogenation components generally make up from about 5% to about 40% by weight of the catalyst. Alternatively, noble metals(preferably used in lower beds), especially platinum and/or palladium, may be present as the hydrogenation component, either alone or in combination with the base metal hydrogenation components molybdenum, tungsten, cobalt, or nickel. If present, the platinum group metals will generally make up from about 0.1% to about 2% by weight of the catalyst.
[0045] Hydrotreating catalyst is preferably used in the upper beds. Hydrotreating catalysts will typically be a composite of a Group VI metal or compound thereof, and a Group VIII metal or compound thereof supported on a porous refractory base such as alumina. Examples of hydrotreating catalysts are alumina supported cobalt-molybdenum, nickel sulfide, nickel-tungsten, cobalt-tungsten and nickel-molybdenum. Typically, such hydrotreating catalysts are presulfided. | The instant invention comprises a hydroprocessing method having at least two stages. The first stage employs a hydroprocessing catalyst which may contain hydrotreating catalyst, hydrocracking catalyst, or a combination of both. The subsequent stage is limited to hydrocracking. Conversion in subsequent stages may be improved by the addition of multiple reaction zones for hydrocracking, with flash separation zones between the stages. Middle distillate yield is thereby increased and the volume of the recycle stream is reduced. This invention reduces the need for equipment which would normally be required for a large recycle stream. | 2 |
CROSS-REFERENCED TO RELATED APPLICATIONS
[0001] This application is a Continuation-In-Part of application Ser. No. 12/649,669, filed Dec. 30, 2009, and this application claims priority from that application which is also deemed incorporated by reference in its entirety in this application.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
FIELD OF THE INVENTION
[0003] The present invention generally relates to a technical field of surgical device, in particular, to a natural orifice transluminal endoscopic surgery (NOTES) device.
BACKGROUND OF THE INVENTION
[0004] At early stage, a surgical operation such as a thoracic surgery generally leaves a large wound and causes a serious postoperative pain to patients. As modern medicine and medical instruments have been advanced, minimal invasive surgery (MIS) has become a trend of current medical treatments. Along with the development of medical imaging equipments, endoscopic surgery has become a representative of minimal invasive surgery. The endoscopic surgery not only brings a revolutionary change to medical treatments only, but also reduces the post-operation pain to patients. Even so, the endoscopic surgery still needs to create several minor wounds on a patient's body in order to let an endoscopic device enter into the patient's body for the surgical operation. Therefore, the patient still has to bear with an acute postoperative pain and requires a follow-up treatment of possible wound scars. Obviously, such surgery has an adverse impact on the quality of life of the patients.
[0005] However, many imaging systems are used for entering the natural orifices of a patient's body for different medical treatments as the medical imaging equipments have been advanced. With the limitations of surgical devices and technologies, scarless surgical operations through natural orifices are still immature. In recent years, the technology of natural orifice transluminal endoscopic surgery (NOTES) has been developed rapidly, and different surgical operations can be performed with an endoscope passed through a natural orifice (such as an oral cavity, a colon cavity, and a birth channel) then through an internal incision into the body. The postoperative wound is reduced significantly, and a scarless operation can be achieved without affecting the patient's appearance and, thus, NOTES has many advantages over laparoscopy and thoracoscopy. However, NOTES requires more sophisticated surgical skills and only an experienced endoscopic surgery doctor to achieve a high success rate and safety.
[0006] The concept of the natural orifice transluminal endoscopic surgery was proposed in 2004. Current literatures related to the successful experience of animal experiments include abdominal and laparoscopic explorations plus liver section surgery, ovary and partial hysterectomy, gastrojejunostomy, tubal ligation, cholecysto-jejunostomy, cholecystectomy, abdominal lymphadenectomy, hernioplasty and proctocolectomy, etc. In 2005, surgical doctors first adopted the NOTES technology on human surgery for appendectomy, and then other NOTES surgeries taken place are laparoscopic exploration and cholecystectomy.
[0007] Popular subjects of the NOTES include: how to select an endoscopic entry, prevention of a postoperative infection, sewing-up a postoperative endoscopic entry, and design of endoscopic equipments. Among them, the design and development of the endoscope are the first step of the development of NOTES. Only the best design and user-friendly surgical machinery can provide a good foundation for the surgery and, thus, it is necessary to design appropriate surgical machinery for a specific natural orifice to achieve the effects of NOTES.
[0008] In view of the aforementioned shortcomings of the prior art, the inventor of the present invention based on years of experience in the related industry to conduct extensive researches and experiments, and finally developed a NOTES device in accordance with the present invention to overcome the shortcomings of the prior art.
SUMMARY OF THE INVENTION
[0009] It is a primary objective of the present invention to overcome the shortcomings of the prior art by providing a natural orifice transluminal endoscopic surgery (NOTES) device which comprises a puncture needle comprising a puncture end, a protruding safety stud disposed at a position substantially at a middle section of the puncture needle, and a positioning projection on an outer surface wherein the puncture needle is provided for puncturing into an internal wall of a nature lumen at the beginning of a surgical procedure; a plurality of dilator sheaths each comprising a plurality of tapered first diameters, an insert member at one end, and a limiting shoulder at the other end, each dilator sheath being sheathed sequentially onto the puncture needle and each dilator sheath further comprising an elongated positioning protrusion on an outer surface and an elongated groove on an inner surface, the groove being disposed correspondingly to the positioning protrusion wherein the positioning projection is complementarily received in the groove when the puncture needle is disposed in the dilator sheath, and the protruding safety stud of the puncture needle is stopped by the limiting shoulder such that such that the insert member is not allowed to pass through the puncture end; a plurality of working sheaths each having a plurality of tapered second diameters, and each of the tapered second diameters of the working sheaths being slightly greater than each of the tapered first diameters of the dilator sheaths wherein each of the working sheaths comprises an elongated positioning protuberance on an outer surface and an elongated trough on an inner surface, the trough being disposed correspondingly to the positioning protuberance, the positioning protrusion being complementarily received in the trough when the dilator sheath is disposed in the working sheath, and the working sheath being used for inserting and retracting the dilator sheaths and the puncture needle after the dilator sheaths have expanded a natural orifice; and a tool member comprising a cylindrical shaft including a graduation on an outer surface, and an operating head threadedly secured to one end of the cylindrical shaft.
[0010] The above and other objects, features and advantages of the invention will become apparent from the following detailed description taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a puncture needle in accordance with a preferred embodiment of the present invention;
[0012] FIG. 1A is a sectional view taken along line A-A of FIG. 1 ;
[0013] FIG. 2 is a perspective view of a dilator sheath in accordance with a preferred embodiment of the present invention;
[0014] FIG. 2A is a sectional view taken along line B-B of FIG. 2 ;
[0015] FIG. 3 is a perspective view of a working sheath in accordance with a preferred embodiment of the present invention;
[0016] FIG. 3A is a sectional view taken along line C-C of FIG. 3 ;
[0017] FIG. 4A is an exploded view of a tool member in accordance with a first configuration of the present invention;
[0018] FIG. 4B is an exploded view of a tool member in accordance with a second configuration of the present invention;
[0019] FIG. 4C is an exploded view of a tool member in accordance with a third configuration of the present invention;
[0020] FIG. 5 is a side view of a puncture needle coupled to a dilator sheath in accordance with a preferred embodiment of the present invention;
[0021] FIG. 5A is a sectional view taken along line D-D of FIG. 5 ; and
[0022] FIG. 6 is a perspective view showing the tool member passing through the working sheath in a surgical procedure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] With reference to FIGS. 1 to 6 , a NOTES device of the present invention is shown. The device comprises a puncture needle 10 , a plurality of dilator sheaths 20 , a plurality of working sheaths 30 , and a tool member 40 . The puncture needle 10 comprises a puncture end 11 , a protruding safety stud 12 disposed substantially at a position of a middle section of the puncture needle 10 . The puncture needle 10 includes an elongated positioning projection 13 on an outer surface ( FIG. 1 ). The puncture needle 10 is provided for puncturing into an internal wall of nature lumen at the beginning of the surgical procedure. The nature lumen wall can be a tracheal wall, or an internal wall of other natural orifices. In the present invention, an embodiment of the tracheal wall is used for the illustration. The dilator sheath 20 comprises a plurality of tapered first diameters (or a series of different successively increasing diameters), an insert member 21 at one end, and a limiting shoulder 22 at the other end opposite to the insert member 21 . Each dilator sheath 20 is sheathed sequentially onto the puncture needle 10 . Each dilator sheath 20 further includes an elongated positioning projection 23 on an outer surface and an elongated groove 24 on an inner surface, the groove 24 being disposed correspondingly to the positioning projection 23 ( FIG. 2 ). The positioning projection 13 is partially, complementarily received in the groove 24 for guiding and positioning purposes when the puncture needle 10 is disposed in the dilator sheath 20 ( FIG. 5 ). Thus, the dilator sheath 20 and the puncture needle 10 can be sequentially slid in place. Otherwise, tissues adjacent the bronchus may be damaged. The protruding safety stud 12 of the puncture needle 10 is stopped by the limiting shoulder 22 such that the insert member 21 will not exceed the puncture end 11 and will form a safety interval from the puncture end. The working sheaths 30 have a plurality of tapered second diameters (or a series of different successively increasing diameters), and each of the second diameters of the working sheaths 30 is slightly greater than each of the first diameters of the dilator sheaths 20 .
[0024] The working sheath 30 comprises an elongated positioning projection 31 on an outer surface and an elongated groove 32 on an inner surface, the groove 32 being disposed correspondingly to the positioning projection 31 ( FIG. 3 ). The positioning projection 23 is complementarily received in the groove 32 for guiding and positioning purposes when the dilator sheath 20 is disposed in the working sheath 30 . The working sheath 30 is used for inserting and retracting the dilator sheaths 20 and the puncture needle 10 after the dilator sheaths 20 have expanded a natural orifice. Only the working sheath 30 is remained to form a space required for the surgical operation. Thus, the working sheath 30 can be correctly guided along the dilator sheath 20 . In addition, a breathing apparatus can be connected when the working sheath 30 is used.
[0025] As shown in FIG. 4A , a first configuration of the tool member 40 comprises an elongated, cylindrical shaft 41 and a steel cutting needle 42 releasably secured to the shaft 41 . The steel cutting needle 42 has an inclined surface with a V-shaped sharp end 421 .
[0026] As shown in FIG. 4B , a second configuration of the tool member 40 comprises an elongated, cylindrical shaft 41 and a steel cutting needle 43 releasably secured to the shaft 41 . The steel cutting needle 43 has a trapezoidal end 431
[0027] As shown in FIG. 4C , a third configuration of the tool member 40 comprises an elongated, cylindrical shaft 41 and a steel cutting needle 44 releasably secured to the shaft 41 . The steel cutting needle 44 has a pointed end 441 .
[0028] In each of the first to third configurations, an externally threaded extension is formed at one end of the shaft 41 and the other end of each of the steel cutting needles 42 , 43 and 44 is provided with an externally threaded hole for threadedly securing to the externally threaded extension of the shaft 41 . Moreover, the tool member 40 further comprises a graduation 410 on an outer surface for measuring the location of damaged tissues and allowing an appropriate surgical instrument to perform a surgical procedure.
[0029] The V-shaped sharp end 421 of the steel cutting needle 42 can be complimentarily disposed on an inclined surface for embedding and cutting a surgical thread at the end of the surgical procedure. Further, the trapezoidal end 431 of another steel cutting needle 43 is used for outward deflecting the tissues in a surgical procedure. It is a physician's choice of using one of the three steel cutting needles 42 , 43 and 44 in surgical procedure.
[0030] The puncture needle 10 has a first length substantially equal to 70 cm.
[0031] The dilator sheath 20 has a second length substantially equal to 33 cm. The safety interval is substantially equal to 2 cm.
[0032] The plurality of first diameters can be equal to 5 mm, 7 mm, 9 mm and 11 mm respectively. In other words, the dilator sheaths 20 have diameters equal to 5 mm, 7 mm, 9 mm, and 11 mm sequentially for expanding an orifice.
[0033] The plurality of second diameters can be equal to 7 mm, 9 mm, 11 mm, and 13 mm respectively. In other words, the plurality of working sheaths 30 can have diameters of 7 mm, 9 mm, 11 mm, and 13 mm respectively for maintaining the smoothness of the orifice during the operation.
[0034] In general, the endoscope is entered from a trachea during a surgical operation, and a rigid (or soft) bronchoscopy is used for the surgical operation, and then the puncture needle 10 is inserted into the trachea, and the plurality of dilator sheaths 20 expand an orifice, and a working sheath 30 is used for maintaining the smoothness of the orifice during the surgical operation, and then a rigid bronchoscopy machinery (a rigid one has been used clinically) is used for a surgical operation, and the tool member also is disposed in the working sheath 30 in the surgical operation ( FIG. 6 ).
[0035] In addition, a method or procedure of the present invention comprises the steps of (a) creating a stable airway by a rigid bronchoscopy; (b) selecting an appropriate puncture position; (c) passing a surgical sheath from a tracheal sidewall situated at a position substantially 3 cm from the top of a tracheal carina and out of a trachea through a natural orifice; (c1) passing a puncture needle 10 out of the tracheal sidewall; (c2) passing a series of dilator sheaths 20 with tapered diameters along the puncture needle 10 sequentially to create an opening; (c3) preventing unnecessary damages by a design of a safety stud 12 which latches the dilator sheath 20 at a position substantially 2 cm from the tip of the puncture needle 10 ; (c4) expanding the opening sequentially, and then retracting the dilator sheath 20 to a position of a sheath with one size smaller than the desired working sheath 30 ; (c5) passing the working sheath 30 through the puncture needle 10 and the opening into a pleural space; (d) using the rigid bronchoscopy machinery for the surgical operation after creating a working channel; (d1) exchanging air by the working sheath 30 of the rigid bronchoscopy during the surgical operation; (d2) prohibiting a removal of the sheath during the surgical operation; (e) making sure that the oxygen level of an experimental animal or a patient reaches 100% before removing the working sheath 30 ; (f) removing the working sheath 30 after the air exchange is terminated; (g) immediately installing a tracheal stent after the working sheath 30 is removed; (g1) selecting the tracheal stent primarily by using a silicone stent (which can be removed easily), and evaluating the tracheal stent by a 3D CT before the surgical operation takes place; (g2) covering the opening of the trachea to avoid a pneumothorax; (g3) performing the endoscopic examination to confirm the position of the stent after the tracheal stent is disposed, wherein if the wound is smaller than one-third of the external circumference of the trachea, then the trachea will be healed automatically; and (h) performing a rigid bronchoscopic examination after the surgical operation takes place, and performing a stent removal operation if the incision healing condition is good. In general, the tracheal stent is covered onto a wound orifice, and the tracheal stent can be removed after two weeks when the wound has been recovered naturally.
[0036] In brief, the present invention provides a NOTES device that is disposed in a trachea to achieve the advantages of the NOTES, and the design of the device provides a user-friendly and easy operation for a scarless surgical operation without affecting a patient's appearance. In addition, the present invention further includes a protruding safety stud disposed at a position substantially at a middle section of the puncture needle, such that the dilator sheath can be latched at a position substantially 2 cm from the tip of the puncture needle to prevent unnecessary damages.
[0037] While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims. | A natural orifice transluminal endoscopic surgery (NOTES) device is provided with a puncture needle including a puncture end, an intermediate protruding safety stud, and a positioning projection on an outer surface; dilator sheaths each including tapered first diameters, an insert member at one end, a limiting shoulder at the other end, a positioning protrusion on an outer surface, and a groove on an inner surface; working sheaths each having a plurality of tapered second diameters and including a positioning protuberance on an outer surface and a trough on an inner surface; and a tool member including a shaft having a graduation on an outer surface, and an operating head threadedly secured to the shaft. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the production of glass mats, and, more particularly, it is concerned with a glass fiber dispersion composition for making uniform, high-strength glass mats by the wet-laid process.
2. Description of the Prior Art
High strength, uniform, thin sheets or mats of glass fibers are finding increasing application in the building materials industry, as for example, in asphalt roofing shingles and as backing sheets for vinyl flooring. These glass fiber mats are replacing similar sheets made traditionally of asbestos fibers. Glass fiber mats usually are made commercially by a wet-laid process, which is carried out on modified paper making machinery, as described, for example, in the book by O. A. Battista, Synthetic Fibers in Papermaking (Wiley) N.Y. 1964. A number of U.S. patents also provide a rather complete description of the wet-laid process, including U.S. Pat. Nos. 2,906,660, 3,012,929, 3,021,255, 3,050,427, 3,103,461, 3,108,891, 3,228,825, 3,634,054, 3,749,638, 3,760,458, 3,766,003, 3,838,995, 3,905,067 and 4,052,257.
The wet-laid process comprises first forming an aqueous suspension or dispersion of a plurality of short-length glass fibers under agitation in a mixing tank. The fibers generally are available commercially as strands or bundles of many parallel fibers which filamentize or separate in the aqueous medium. The dispersion composition then is fed through a moving screen on which the fibers enmesh themselves while water is being removed.
Unlike natural fibers, such as cellulose or asbestos, however, glass fibers do not disperse well in water, even when stirred vigorously. In fact, upon extended agitation, the fibers actually agglomerate as large clumps which are very difficult to redisperse. In an attempt to overcome this inherent problem with glass fibers, it has been the practice in the industry to provide suspending aids for the glass fibers, including surfactants, in order to keep the fibers separated from one another in a relatively dispersed state. Such suspending aids usually are materials which increase the viscosity of the medium so that the fibers can suspend themselves without entangling. Some suspending aids actually are surfactants which function by reducing the surface attraction between the fibers. Unfortunately, however, none of the available suspending aids are entirely satisfactory for large volume manufacture of useful, uniform high strength glass fiber mats.
In the copending application, Ser. No. 851,683 (FDN-1062) filed Nov. 15, 1977, and assigned to the same assignee as the present application, there is described the use of amine oxide surfactants for forming well-dispersed glass fiber compositions. However, it is the object of this invention to provide improved dispersion compositions, which includes amine oxides in synergistic combination with another dispersing aid, for manufacture of uniform, high-strength glass mats suitable for industrial application.
SUMMARY OF THE INVENTION
This invention provides a novel aqueous glass fiber dispersion composition for making uniform, high-strength glass mats by the wet-laid process in which a plurality of glass fibers are very well dispersed in an aqueous system comprising an effective amount of an amine oxide and derivatized guar gum.
In another aspect of the invention, there is provided a method of producing such glass mats using said dispersion composition.
DETAILED DESCRIPTION OF THE INVENTION
Description of the Preferred Embodiments
In accordance with the present invention, there is provided herein a dispersion composition which meets a number of criteria simultaneously for making high quality, uniform, high-strength glass mats at a rapid rate of production and in an economically acceptable process. These features and advantages are listed below.
1. The dispersion composition of the invention provides a well-dispersed fiber system over a broad range of fiber consistencies, extending to very high fiber consistencies, both at the dispersion and mat-forming stages of the wet-laid process. Thereupon glass mats of desired basis weight are formed at a resonable rate.
2. The dispersion composition herein can be used in conjunction with manny different mat-forming machines, including flat, cylindrical or inclined wire machines. Therefore conventional paper making equipment as well as machines designed specifically for glass mat manufacture may be utilized with the dispersion composition of the invention.
3. The composition herein provides effective dispersions of glass fibers using dry or wet chopped fibers, which are sized or unsized, and which have a broad range of fiber lengths and diameters.
4. Production of glass mats can be carried out without forming unwanted foams.
5. The dispersion composition can be agitated for extended periods of time without affecting the quality of the glass mats produced therefrom.
6. The dispersion composition which is removed during mat formation can be recycled without affecting the uniformity and high-strength properties of the glass mats.
These and other advantages and features of the invention will be made apparent from the following more particular description of the preferred embodiments thereof.
In general, the glass fiber dispersion composition is made by thoroughly mixing the derivatized quar gum (hereinafter defined) component in tap water to form a viscous mixture. Then the amine oxide constituent is added with stirring, and chopped glass fiber strands are admixed to form the desired fiber dispersion composition.
After preparation of the stock glass fiber dispersion composition in this manner, the dispersion is pumped to a head box of a mat-forming machine where the desired glass mat is formed as a wet mat on the belt of the machine. The wet mat then may be dried, if necessary, then treated with a suitable binder, and, finally, thoroughly dried.
The glass mats of the invention exhibit uniformity of enmeshed glass fibers, and excellent high-strength properties, as measured by their tensile and tear strengths.
The derivatized guar gum component of the dispersion composition of the invention is characterized by the presence of substituent groups attached to guar gum itself. Derivatized guars suitable for use herein are identified as such in the commercial products which are available from Stein, Hall and Co., Inc. Typical derivatized guars include JAQUAR CMHP, which is a carboxymeth ylhydroxypropylated guar gum; C-13, which is a quaternary ammonium quar gum; and JAQUAR HP-11, which is a hydroxypropylated quar gum.
The amine oxide surfactant component of the dispersion composition is a tertiary amine oxide having the formula: ##STR1## where R 1 , R 2 and R 3 suitably are hydrocarbon groups containing between 1-30 carbon atoms. The hydrocarbon groups can be aliphatic or aromatic, and, if aliphatic, can be linear, branched or cyclic, and can be the same or different in each radical. The aliphatic hydrocarbon radical also can contain ethylenic unsaturation. Preferably, aliphatic groups are selected from among alkyl groups, such as lower alkyl or hydroxyalkyl groups having from 1-4 carbon atoms, and other substituted alkyl groups thereof, or long chain alkyl groups, having from 12-30 carbon atoms, such as stearyl, laurel, oleyl, tridecyl, tetradecyl, hexadecyl, dodecyl, octadecyl, nonadecyl, or substituted groups thereof, derived from natural or synthetic sources. The sum of the R 1 , R 2 and R 3 groups is about 14-40 carbon atoms, and, most preferably, about 18-24 carbon atoms.
Typical commercial amine oxides suitable for use herein include Aromox DMHT, which is dimethyl hydrogenated tallow amine oxide; Aromox DM16, which is dimethylhexadecylamine oxide; Aromox T/12, which is bis(2-hydroxyethyl) tallow amine oxide, available from Armak Co.; and Ammonyx SO, which is dimethylstearylamine oxide, available from Onyx Chemical Co.
A particularly useful amine oxide is Aromox DMHT, which has the formula: ##STR2## where R HT is R T hydrogenated to saturation, and R T is 3% tetradecyl, 27% hexadecyl, 16% octadecyl, 48% octadecenyl and 6% octadecadienyl.
The mechanism of the synergistic effect developed by the combination of derivatized guar with amine oxide in forming an excellent fiber dispersion system, and of providing high quality glass mats therefrom, is not clearly understood at present. However, it has been verified experimentally that the individual dispersing components do not perform nearly as well as the combination thereof. Furthermore, it is believed that the synergistic effect of this invention is not simply a change in the viscosity of the medium, since thickening amine oxides with the conventional thickening agents does not provide the same advantageous dispersing medium as with derivatized guars.
In order to further define the invention with particularity so that it may be carried out advantageously, the suitable, preferred and best mode parameters of the process of the invention are given below in Table I. The following definitions apply to this data:
"Dispersion consistency" is the percent by weight of the glass fibers in the stock aqueous dispersion medium. "Formation consistency" is defined as the consistency of the fibers at the head box of the mat-forming machine, which may be the same or lower consistency than the dispersion consistency. The dispersion composition may be diluted with water before entering the head box; this "diluted formation consistency" is given in Table I. The "amine oxide concentration" is given in ppm of this component. The "derivatized guar gum concentration" is indicated as percent by weight of the composition.
TABLE I__________________________________________________________________________NUMERICAL PARAMETERS OF THE PROCESS OF THE INVENTIONFiber Diluted Fiber Conc. of GlassDispersion Formation Conc. of Derivatized Glass FiberConsistency Consistency Amine Oxide Guar Gum Fiber Diameter(%) (%) (ppm) (% by wt.) Length (in.) (microns)__________________________________________________________________________SuitableRange 0.1-2% 0.01-1% 5-500 0.05-0.5 1/8-3 3-20PreferredRange 0.2-1% 0.02-0.5% 10-200 0.1-0.3 1/4-2 5-18Best ModeValue 0.5 0.03 20 0.2 1 16__________________________________________________________________________
Commercial glass fibers which form dispersions in the composition of the invention may be used herein, including, for example, glass fiber types E or C. Such fibers may be sized or unsized, and usable as dry or wet chopped form.
The fibers may be coated initially by spraying or otherwise applying the amine oxide surfactant thereon, and then dispersing the coated fibers in the aqueous derivatized guar gum medium. In this procedure, the coated fibers contain about 0.01 to 1% by weight of the amine oxide, and, preferably about 0.025 to 0.25%.
The glass mats produced in the process are uniform mats which have high tensile and tear strengths. For increased tensile strengths, generally, fibers of relatively lower diameters are used, while higher tear strengths are enhanced by using longer length and smaller diameter fibers.
The examples which follow will illustrate the invention, but are not to be considered as being limiting of the principles or practice thereof.
EXAMPLE 1
In this example, laboratory dispersion compositions were prepared using various derivatized guar gums at different usage levels in combination with 20 ppm of Aromox DMHT amine oxide. The dispersions were made with glass fiber type E, sized, dry chopped, 6 mm length and of 16 micron diameter, at a dispersion and formation consistency of 0.3% by weight. The dispersion composition was made by thoroughly mixing the derivatized guar gum in plain tap water until viscous, then admixing the amine oxide, and finally adding the fibers.
The glass mats were made in a Williams Handsheet Mold by dewatering the fiber dispersion through a stationary screen. The wet mats were further dewatered under vacuum and a urea-formaldehyde binder applied. The samples then were dried and cured by heating. The quality of the dispersions and the glass mat produced thereby were compared and the results are presented in Table II below.
TABLE II______________________________________QUALITY RATINGS OF DISPERSIONS AND GLASS MATS Usage Level of DerivatizedExp. Derivatized Guar Quality of Quality ofNo. Guar (% by wt.) Dispersion Glass Mat______________________________________1 CMHP 0.2 E E2 CMHP 0.1 E E3 CMHP 0.05 E E-G4 C-13 0.2 E E-G5 C-13 0.1 G G-F6 C-13 0.05 G-F G-F7 HP-11 0.2 E G8 HP-11 0.1 G F9 HP-11 0.05 F F______________________________________ (WHERE E IS A QUALITY RATING OF EXCELLENT, GGOOD AND FFAIR)
When the same experiments were carried out without the derivatized guar gum component being present in the dispersion composition, or with Cytame 6, a polyacrylamide viscosity modifier, in its place, the results, on a comparative basis, were rated as poor, for both quality of the dispersion and of quality of the glass mat.
EXAMPLE 2
In this example, the mat former was a 0.5 m flat wire Fourdrinier Machine. The dispersion composition was prepared by mixing Aromox DMHT at 20 ppm and 0.2% CMHP in tap water with glass fibers, E-type, 13 mm in length, 13 micron diameter, sized, wet chopped fibers, to a 0.3% dispersion consistency. The strands of fibers were completely filamentized and uniformly distributed as an excellent dispersion in the aqueous medium. The stock dispersion was fed to the headbox of the mat-former without dilution to form a glass mat whose fibers were uniformly distributed throughout the mat. A urea-formaldehyde binder than was applied. The resultant glass mat had a 100 g/m 2 basis weight and excellent tensile and tear-strengths.
When the above example was repeated without the derivatized guar gum component, the quality of dispersion and glass mat was rated only as poor by comparison.
EXAMPLE 3
In this example, the mat-forming machine was a 0.5 m inclined wire Hydroformer. The dispersion composition consisted of Aromox DMHT, 20 ppm, CMHP, 0.2% E-type glass fibers, 25 mm length, 16 mm diameter, sized, and wet chopped. The dispersion consistency was 0.5%; the diluted formation consistency was lowered to 0.03, after dilution with additional dispersion composition removed during mat formation at the headbox. The dispersion quality was observed to be excellent. The glass mat with binder had an excellent tensile strength, N/50 mm width, MD/CMD of 500/282, at a basis weight of 110 g/m 2 , even after many runs.
When the above example was repeated without CMHP, the dispersion and mat qualities were not as good as with the combination of components. The tensile strength of the mat, at the same basis weight, was reduced to 158/122.
EXAMPLE 4
In this example, the mat-forming machine was a 14 ft. wide, flat wire Fourdriner. The dispersion composition was Aromox DMHT, 20 ppm, CMHP, 0.2%, E-type fibers, sized, 13 mm length, 13 microns diameter, wet chopped fibers. The dispersion consistency was 0.3%. The dispersion was pumped to the headbox of the machine without dilution. The mat formed was of excellent quality, having a tensile strength, N/50 mm width, MD/CMD of 709/140, at a basis weight, with binder, of 95 g/m 2 .
When the example was repeated without the CMHP, the mat had a much lower tensile strength of 292/110, and was inferior in uniformity. | This invention describes an aqueous, glass fiber dispersion composition for making uniform, high strength glass mats which comprises a plurality of glass fibers dispersed in an aqueous system comprising an effective amount of an amine oxide and a derivatized guar gum.
A wet-laid process for making such mats using said dispersion composition also is described. | 3 |
REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 11/637,238, filed Dec. 12, 2006, which claims the priority of U.S. Provisional Application Ser. Nos. 60/749,103, filed Dec. 12, 2005, and 60/755,079, filed Jan. 3, 2006, the contents of which prior applications are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to an endoprosthesis for replacement of a joint, comprising a component which is to be connected to a lower bone and which has a top slide surface, a component which is to be connected to an upper bone and which has a bottom slide surface, and an intermediate part which, on its bottom and top, has in each case a matching slide surface which, together with the slide surfaces of the aforementioned components, in each case forms a bearing.
BACKGROUND OF THE INVENTION
[0003] Endoprostheses of this kind are used, for example, for replacement of the ankle joint (FR-A-2 676 917, WO-A-03/075802, WO-A-2005/030098). In these, the components and the intermediate part cooperate via slide surfaces which permit flexion and extension in a sagittal plane. The sagittal plane is in this case a plane which is defined by AP direction and the vertical axis. The tibial component and the intermediate part form interacting slide surfaces which permit a rotation about the vertical axis. They can have a plane configuration in order to permit compensating movements in the AP direction and LM (lateral-medial) direction. So that the joint has degrees of freedom with respect to rotary, pivoting and/or shearing movements, which degrees of freedom correspond to the natural model, the slide surfaces correspondingly have different contours, for example a flat slide surface is combined with a slide surface which is curved in the manner of a cylindrical sleeve. Stabilization is afforded by the natural ligament apparatus.
[0004] The full load of the endoprosthesis rests on the intermediate part. The latter is therefore subject to substantial loading. In practice it has been found that substantial loads can result in a “warping” of the intermediate part normally made of polyethylene. There is therefore a danger that, under increased loads, as may occur for example as a result of movement dynamics (in particular when climbing stairs or jumping), the intermediate part will become overloaded and thus suffer uncontrolled deformation. This can lead to excessive wear, cold flow, or even malfunction of the prosthesis as a result of material failure. This is in particular the case if the intermediate part has a thin design, as is usually the case as a consequence of the different contours of the slide surfaces.
SUMMARY OF THE INVENTION
[0005] Starting out from the cited prior art, the object of the invention is to improve an endoprosthesis of the type mentioned in the introduction in such a way that it can more reliably withstand high loads while maintaining multiple degrees of freedom.
[0006] The solution according to the invention lies in a prosthesis including a first bone component configured for connection to a lower bone and having a bottom slide surface, a second bone component configured for connection to an upper bone and having a top slide surface, an intermediate part having slide surfaces on its bottom and top which, together with the slide surfaces of the first and second bone components define a movement plane for a bearing, the slide surfaces of the intermediate part having different contours, and a clamping bracket enclosing side surfaces of the intermediate part and arranged on the intermediate part free from the movement planes defined by the slide surfaces of the intermediate part. Advantageous developments are explained in the detailed description below.
[0007] Accordingly, in an endoprosthesis for replacement of a joint, comprising a component which is to be connected to a lower bone and which has a top slide surface, a component which is to be connected to an upper bone and which has a bottom slide surface, and an intermediate part which, on its bottom and top, has in each case a slide surface which, together with the slide surfaces of the aforementioned components, in each case define a movement plane for a bearing, the slide surfaces of the intermediate part having different contours, the invention proposes that a clamping bracket encloses the side surfaces of the intermediate part and is arranged on the intermediate part free from the movement planes defined by the slide surfaces having different contours. The term movement plane is to be interpreted in a broad sense and also includes curved contours.
[0008] With the clamping bracket acting as a belt of greater tensile strength compared to the polyethylene, the resulting overall modulus of elasticity of the intermediate part is increased. The clamping bracket is for this purpose expediently made from a material such that it has an at least fifty times, preferably at least two hundred times, greater modulus of elasticity than the polyethylene. With the clamping bracket acting as a belt with tensile strength, elastic or plastic deformation of the intermediate part under loading is counteracted. The intermediate part can thus also withstand greater loads without deforming. Thus, the intermediate part can be strengthened with the clamping bracket according to the invention. By virtue of the inventive design of the clamping bracket, the movement surfaces, as are defined by the slide surfaces of the upper and lower bearing, remain free. Thus, despite the strengthening by the clamping bracket, the mobility of the endoprosthesis is maintained in all functions of the joint. This applies not only to the normal range of movement of the endoprosthesis, but also to movements going beyond these, such as may occur for example upon twisting of the foot.
[0009] It has of course been made known for polyethylene plateaus, functioning as part of knee-joint endoprostheses, to be strengthened by providing a metal plate on the underside of the plateau resting on the tibia. In this way, the polyethylene plateau has been strengthened from its rear face in such a way that it yielded less under flexural stress. However, this strengthening measure known from EP-A-0 829 243 can be used only in prostheses which have a slide surface on just one side. In an endoprosthesis of the type in question here, the intermediate part has slide surfaces on its top and also on its bottom, thus ruling out the use of such a strengthening plate. The same applies to a strengthening ring as disclosed in U.S. Pat. No. 5,766,256. This ring too is arranged on the bottom face, which does not serve as a joint surface.
[0010] The clamping bracket is preferably designed with two zones, namely with a belt zone extending in the circumferential direction and a spread protection zone which adjoins the belt zone. In this connection, the spread protection zone does not have to be provided all round the circumference, and instead it generally suffices for it to be provided on two opposite sides. The spread protection zone additionally counteracts a divergence of the outer portions of the intermediate part under high flexural stress.
[0011] The top and bottom edge of the clamping bracket are preferably adapted to the contour of the respectively adjacent slide surface. Adapted is here understood as meaning that, seen in a side view, the edge of the clamping bracket is at a constant distance from the edge of the adjacent slide surface. If the one slide surface is for example a plane, then its edge is a straight line and the corresponding edge of the clamping bracket is likewise a straight line; if the other slide surface is correspondingly curved, its edge is in the shape of an arc of a circle and the corresponding edge of the clamping bracket is likewise an arc of a circle with an edge in the shape of an arc of a circle. The top and bottom edges of the clamping bracket being adapted to the respective contour makes it possible to achieve a strengthening of the particularly loaded intermediate part, even in the case of endoprostheses having complex joint function, such as those having slide surfaces with different contours, and still to ensure that the element effecting the strengthening, the clamping bracket, remains free from the complex movement planes defined by the slide surfaces with different contours.
[0012] The clamping bracket at its bottom edge expediently has, at least on two sides, a bevel which is configured such that it merges smoothly into the intermediate part. On its inner side, the clamping bracket also preferably has a bead-like projection which engages in a corresponding recess on the intermediate part. The clamping bracket is thus secured against an undesired displacement from its intended position. However, other securing techniques can also be provided, for example adhesive bonding or binding, generated in particular by shrinking the clamping ring onto the intermediate part. A form-fit connection can also be provided, for example pinning or screwing.
[0013] In order to give the clamping bracket a defined position on the intermediate part, it has, on its top or bottom, a flange on which the clamping bracket bears. This makes fitting of the clamping bracket easier, since the intended position is clearly defined. This also has the effect that the slide surface of the intermediate part does not have to be made smaller because of the clamping bracket. In this way, the surface load is not any greater than in the conventional design of the intermediate part without clamping bracket.
[0014] The clamping bracket is expediently dimensioned such that its top edge and its bottom edge are at a distance of at least 1 mm, preferably between 1.5 and 2.5 mm, from the edge of the respective slide surface. This ensures that, even in the event of a high load leading to compression of the intermediate part, or in the event of wear of the intermediate part, it is possible to avoid undesired contact between the clamping bracket and the slide surfaces of the components of the prosthesis.
[0015] According to a particularly preferred embodiment, which possibly merits independent protection also for endoprostheses having slide surfaces with the same contour, the clamping bracket has a convex projection on at least one outer face. The effect of the projection is that, in the event of a rotation, as also in a linear movement, of the joint and thus also of the intermediate part and clamping bracket, undesired tissue material growing laterally alongside the endoprosthesis can be forced back. It is in this way possible to counteract or even prevent infiltration of this tissue material, so-called fibrosis. The danger of the joint with the endoprosthesis according to the invention having its mobility restricted by excessive fibrosis can thus be averted. Pain which can normally occur in the event of such fibrosis, on account of the tissue material growing in the area of movement of the intermediate part, is avoided by virtue of the development according to the invention. By virtue of the configuration according to the invention, an otherwise unavoidable surgical removal of this tissue material is unnecessary.
[0016] A particular advantage of this development is that, with the clamping bracket preferably made of metal, a contact with the bone or the tissue material can in principle take place, whereas, in the intermediate parts customarily made exclusively of polyethylene material, a contact with the bone or the tissue material was not desirable, because this leads to undesired polyethylene abrasion. The configuration according to the invention thus makes use of the clamping bracket in two ways, namely its structure for forming the convex projection for forcing back the fibrosis, and its material which for the first time permits contact with the fibrotic tissue material.
[0017] The convexity of the projection need only be one-dimensional, such that an essentially cylindrical shape is obtained; however, it can preferably also be two-dimensional, such that an essentially spherical configuration is obtained, in which case the curvature in the plane of the clamping bracket and perpendicular thereto can be different.
[0018] The convex projection expediently extends across the entire length of the respective outer face. Although the desired effect can in principle also be achieved with a projection extending over only part of the length of an outer face, greater and therefore more favorable radii of curvature for the projection arise in a design across the entire length. An arrangement of the convex projection on a medial longitudinal face of the clamping bracket is particularly expedient. In the case of an implantation of the endoprosthesis according to the invention on the ankle joint for example, the medial malleolus is situated in this area. It is in this very area that undesired fibrosis may occur, the damaging results of which can be prevented by virtue of the development according to the invention. The arrangement extending across the entire length also has the advantage that the desired effect of the forcing back can be achieved also in a non-rotational movement, for example a linear forward and rearward movement of the intermediate part.
[0019] The contour of the convex projection is expediently chosen such that it has the shape of an arc of a circle in plan view. Such a contour is favorable in production and gives a uniform curvature of the projection without pronounced changes to the curve profile. It is not necessary here for the center of the circle arising from the arc to lie centrally in the clamping bracket. It is expediently offset in the direction of the opposite lateral face. This results in an eccentricity, on the basis of which a stronger forcing back of the fibrotic tissue material is achieved with greater rotatory deflections of the intermediate part.
[0020] The outer face of the convex projection is preferably smooth. It can preferably be polished. This gives a form that promotes sliding, in particular under the influence of tissue fluid. The danger of tissue material being torn off is thus effectively counteracted.
[0021] The convex projection can expediently also be provided on the adjacent outer faces. In the case of a rectangular design, this means that such a convex projection is formed on the anterior face, the posterior face and the medial face of the clamping bracket.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention is explained below with reference to the attached drawing which depicts an advantageous illustrative embodiment of the invention and in which:
[0023] FIG. 1 shows a sagittal section through an ankle joint fitted with the prosthesis according to the invention;
[0024] FIG. 2 shows the prosthesis according to FIG. 1 in a perspective view and opened out;
[0025] FIGS. 3 a ), b ) show a front view and a side view, respectively, of a clamping bracket of the prosthesis;
[0026] FIG. 4 shows a partial cross-sectional view of the clamping bracket with an intermediate part of the prosthesis;
[0027] FIG. 5 shows a front view of a lower area of the shin bone with a part of a variant of the endoprosthesis according to FIGS. 1 to 4 ;
[0028] FIG. 6 shows a bottom view of the variant according to FIG. 5 , and
[0029] FIGS. 7 a ), b ) show a front view and side view, respectively, of the clamping bracket shown in FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0030] The depicted illustrative embodiment of the prosthesis according to the invention is an ankle joint prosthesis. It will be noted that the invention can also be applied to other types of endoprostheses, for example intervertebral endoprostheses. The important point is that the endoprosthesis has two bearings whose planes of movement are defined by the slide surfaces having different contours.
[0031] The endoprosthesis according to the depicted illustrative embodiment basically comprises three components. The first component is a shin bone component 1 designed to be arranged on the lower end of a tibia 91 . It has a plate-shaped part 10 whose bottom forms a plane slide surface 11 . On the top of the plate-shaped part 10 there is an anchoring body 12 which is provided with projections and which serves to secure the shin bone component 1 in corresponding resection depressions in the tibia 91 .
[0032] The prosthesis further comprises an ankle bone component 4 . It has a saddle-like configuration and has a convexly curved slide surface 44 on its top. It can be configured in the manner of a jacket of a cylinder, as shown here. However, it can equally well have a cone-shaped design. A guide rib 46 , which lies in the AP direction, is arranged on it. This serves for guiding purposes in a flexion and extension movement of the ankle joint.
[0033] An intermediate part 2 is arranged between the shin bone component 1 and the ankle bone component 4 . On its top, it has a plane slide surface 21 which is configured to match the slide surface 11 of the shin bone component 1 . On its bottom, the intermediate part 2 has a slide surface 24 which is congruent to the slide surface 44 of the ankle bone component 4 . It additionally has a groove 26 which is designed to receive the rib 46 in a longitudinally displaceable manner. In this way, the intermediate part 2 is guided laterally in relation to the ankle bone component 4 . Only flexion and extension movements are thus permitted. By contrast, the plane slide surfaces 11 , 21 permit any desired movement in a horizontal plane, that is to say both longitudinal and transverse movements and also, in particular, a rotation about the vertical axis.
[0034] The shin bone component 1 and the ankle bone component 4 are expediently made of metal, for example a cobalt-chromium alloy provided on its respective outer face with a coating that promotes bone growth (for example calcium phosphate). The intermediate part 2 , by contrast, is preferably made of a plastic material that promotes sliding, in particular polyethylene. However, this is not intended to rule out the possibility of also using other materials with sufficient strength and slidability.
[0035] In the implanted state, the joint, and in particular the intermediate part 2 , is subjected to a high axial load (symbolized by an arrow 95 ) along the vertical axis. On account of the resulting compression, a horizontally outwardly directed divergent force arises in the polyethylene material of the intermediate part 2 (as symbolized in FIG. 1 by the arrows 96 ). This divergent force is further intensified by the convex configuration of the slide surface 44 of the ankle bone component 4 . High loads may therefore result in an undesired deformation of the intermediate part 2 .
[0036] To counteract this, a clamping bracket 3 according to the invention is provided. It is made of a cobalt-chromium alloy with a modulus of elasticity which is approximately four hundred times as high as that of the polyethylene material of the intermediate part 2 . It is also possible to use titanium, which has an approximately two hundred times higher modulus of elasticity. The clamping bracket 3 is made from a flat strip material. It has a thickness of 1 mm, for example. In horizontal section, the clamping bracket 3 has a contour corresponding to the outer contour of the intermediate part 2 . In the illustrative embodiment shown, this is a quadratic contour. However, another contour could equally well be provided, for example a round one in the case of a design as an intervertebral prosthesis. Its dimensions are chosen such that it tightly encloses the intermediate part 2 .
[0037] In its upper part, the clamping bracket 3 has a circumferential belt zone 36 . This counteracts a deformation of the intermediate part 2 in all lateral directions (in longitudinal direction and in transverse direction) under loading. In addition, the bottom of the belt zone 36 is adjoined by a spread protection zone 37 . The spread protection zone 37 , to which the bevel 32 also belongs, additionally stabilizes the outer areas of the concave slide surface 24 and thus counteracts in a particularly effective manner the divergent force component 96 resulting from the convex configuration of the slide surface 44 . The intermediate part 2 is thus strengthened by virtue of the clamping bracket according to the invention. Thus, even in the event of a high load, undesired bending deformation is counteracted.
[0038] The clamping bracket 3 is straight at its top edge 31 . This results in a constant distance from the edge of the top slide surface 21 . On its bottom edge 34 , the clamping bracket has an arcuate configuration on its longitudinal sides 33 (which are oriented parallel to the rib 46 ). It is configured such that in this area there is a constant distance of the bottom edge 34 of the clamping bracket 3 from the edge of the lower slide surface 24 . On its transverse sides 35 , the clamping bracket 3 has a straight bottom edge. This once again results in a constant distance from the corresponding edge of the slide surface 24 . In the area of the transverse sides, the bottom edge of the clamping bracket is extended downward like an apron and also has a bevel 32 . The latter is configured such that it forms a continuous plane with the corresponding side surface 22 of the intermediate part 2 . The bevel provides additional strengthening specifically in an area which is particularly loaded by the divergent forces (see arrow 96 ), and specifically in a way that does not involve undesired restriction of mobility.
[0039] The intermediate part 2 has a flange 20 in the area of its upper slide surface 21 . The clamping bracket 3 is pushed flush onto the underside of the flange 20 in such a way that a smooth transition is formed on the outside between the flange 20 and the outer face of the clamping bracket 3 .
[0040] By virtue of the inventive configuration of the clamping bracket 3 , the upper and lower slide surfaces 21 , 24 remain free, such that their bearing function is not adversely affected.
[0041] As a further illustrative embodiment, FIGS. 5 to 7 show a variant of the ankle-joint endoprosthesis according to FIGS. 1 to 4 . FIG. 5 shows the endoprosthesis at its intended implantation site on the distal end of the tibia 91 . For the sake of clarity, the only parts of the endoprosthesis that are shown here are the shin bone component 1 , the intermediate part 2 and a varied clamping bracket 3 ′. The fibula 90 runs parallel to the tibia 91 . At its distal end, the tibia 91 forms a plateau on which the shin bone component 1 of the endoprosthesis according to the invention is arranged. This plateau is limited in the medial direction by a continuation of the tibia 91 , the so-called medial malleolus 93 , and in the lateral direction by a corresponding continuation of the fibula 90 , namely the lateral malleolus 94 . They enclose the plateau of the tibia 91 and therefore the shin bone component 1 of the endoprosthesis like a fork. This can be seen clearly in FIG. 6 .
[0042] It has been shown that, some time after implantation, a formation of tissue material (fibrosis) 99 often occurs in the area between the medial malleolus 93 and the intermediate part 2 or the clamping bracket 3 ′ arranged around the latter. This can cause pain which not only could be very unpleasant for the patient but in quite a few cases could also necessitate a surgical intervention to remove the tissue material 99 . To avoid or reduce the fibrotic tissue material 99 , a projection 39 is formed at least on a longitudinal face 33 of the clamping bracket 3 ′, expediently on the medial face. The projection extends outward relative to a contour which is congruent with the intermediate part 2 . A projection of this type which projects over the congruent contour may also be provided on endoprostheses which have slide surfaces having the same contours. The projection preferably has an arc-shaped outer contour, the arc extending across the entire length. The projection 39 is expediently curved in two dimensions, that is to say it has a spherical surface shape (see FIG. 7 a ). The radii of curvature are of different sizes, a weak curvature in the horizontal plane (as is shown in FIG. 6 ) and a stronger curvature in a frontal plane (as is shown in FIG. 7 a ). To obtain the largest possible radius of curvature in the horizontal plane, the midpoint 30 of the circle defined by the radius of curvature preferably does not lie centrally in the clamping bracket 3 ′ but is instead eccentrically offset in the lateral direction and preferably also in the frontal direction. The outer face of the projection 39 is smooth.
[0043] The illustrative embodiment shown represents one option, specifically one in which the front face and the rear face of the clamping bracket 3 ′ are also each provided with a projection 39 ′ and 39 ″, respectively. They are expediently configured corresponding to the projection 39 , but can also deviate from this in shape (e.g. cylindrical instead of spherical, as is shown in FIG. 7 b ). A transition of equal curvature between the projections 39 , 39 ′, 39 ″ is not necessary, but the geometries are expediently chosen such that the transition is stepless. The lateral longitudinal face of the clamping bracket 3 ′ expediently has no projection. This serves to ensure free movement of the clamping bracket. This also has the advantage of providing an unambiguous orientation of the clamping bracket 3 ′, as a result of which the danger of its being fitted in an incorrect position is reduced.
[0044] Like the clamping bracket 3 of the illustrative embodiment shown in FIGS. 1 to 4 , the clamping bracket 3 ′ is preferably made of a metal material, in particular titanium or a cobalt-chromium alloy. It can thus come into contact with the fibrotic tissue material 99 without there being any risk of its adversely affecting the surrounding tissue. Upon movement of the endoprosthesis, in particular upon rotation, but also upon movement in the longitudinal direction toward the front or rear, the projection 39 ensures that the fibrotic tissue material 39 is forced back. This therefore effectively counteracts growth of the fibrotic tissue material 99 into the area of the endoprosthesis.
[0045] The projection 39 is normally designed in one piece with the clamping bracket 3 ′. However, this should not rule out the possibility of choosing a multi-part construction in which the projection 39 is designed as a separate part and is secured on the clamping bracket 3 ′ by suitable securing means. The latter affords the advantage that, for the projection 39 , it is possible to choose a material which especially promotes sliding and is especially suitable for contact with the fibrotic tissue material 99 , without concerning oneself about its mechanical load-bearing capacity as strengthening element, as is important for the choice of the material for the clamping bracket 3 .
[0046] Finally, it will be noted that the configuration according to the invention of a clamping bracket with a projection 39 is not limited to ankle-joint endoprostheses. | An endoprosthesis for replacement of a joint includes two slide surfaces having different contours and correspondingly determining movement planes for a bearing formed by an intermediate part. The endoprosthesis includes a clamping bracket to enclose the slide surfaces of the intermediate part that is arranged thereon such that it is free from the movement planes defined by the slide surfaces having different contours. It is thus possible to strengthen endoprostheses which have complex biomechanics having a plurality of degrees of freedom. | 0 |
FIELD OF THE INVENTION
The present invention relates to a universal-serial-bus (“USB”) hub circuit and a display device to which a plurality of computers can be connected.
BACKGROUND OF THE INVENTION
In recent years, computers have been used in various applications. Some display devices such as those using CRT, LCD, or plasma are connectable to a plurality of computers. For example, a user who operates two computers assigns different jobs to respective computers. In this case, one display device is connected up to these two computers, and the user can select the computer through the display device. Among these smart display devices, some of them include a function for selecting an active computer by detecting signals from the computer.
A display device incorporating a USB hub circuit has drawn attention from the market, and a number of such display devices have increased recently. The USB hub circuit under the common standard with peripheral devices such as a mouse, keyboard and the like is defined as shown in FIG. 4. A USB hub circuit 31 has two types of connections, i.e. one is an upstream terminal 32 for connecting to a computer, and another is a plurality of downstream terminals 33 for USB devices. For instance, when a user connects a USB compatible computer 34 to a display device having a built-in USB hub circuit, the display device is coupled to the computer 34 via the upstream terminal 32 . On the other hand, the USB compatible keyboard and mouse 35 are coupled to the display device via downstream terminals 33 . This construction allows the keyboard and mouse to be connected directly to the display device that is placed just in front of the computer, i.e. at the user side. Further, this construction advantageously simplifies the connections because the same connecting terminals are used.
The display device incorporating the USB hub circuit 31 , however, has the following inconveniences with all the advantages discussed above. Since the USB hub circuit 31 has only one upstream terminal 32 , the computer must be re-connected via the upstream terminal 32 to the circuit 31 every time when the user changes the computer. The re-connection annoys the user and wastes time.
SUMMARY OF THE INVENTION
The present invention addresses the problem discussed above, and aims to provide a USB hub circuit and a display device. Through the circuit and device, a computer to be used can be selected with ease.
The USB hub circuit of the present invention comprises the following elements:
a switch circuit disposed between a plurality of upstream terminals to which respective computers are connected and a USB hub section; and
a selector for coupling the USB hub section with a selected upstream terminal determined by operating the switch circuit.
A first type display device of the present invention incorporates the above mentioned USB hub circuit.
This construction allows the display device to select a computer to be used only by switching the switch circuit through the selector. Re-wiring between the computer and the USB hub section can be thus advantageously eliminated.
A second type display device of the present invention comprises the following elements:
a first switch circuit disposed between a plurality of upstream terminals to which respective computers are connected and a USB hub section;
a second switch circuit disposed between a video display circuit and a plurality of video and sync. signal-input-terminals, and the same computer is connected to respective terminals; and
a selector for coupling the USB hub section with a selected upstream terminal as well as the display circuit with a selected video and sync. signal-input-terminal by operating the first and second switch circuits.
This construction allows the second type display device to select a computer to be used only by switching the first switch circuit. At the same time, it also allows the second type display device to switch the display screen proper to the computer to be used by the second switch circuit.
A third type display device of the present invention comprises the following elements:
a first switch circuit disposed between a plurality of upstream terminals to which respective computers are connected and a USB hub section;
a second switch circuit disposed between a video display circuit and a plurality of video and sync. signal-input-terminals, and the same computer is connected to respective terminals; and
a controller for identifying an active computer based on the sync. signal supplied through the second switch circuit, and for coupling the USB hub section with the upstream terminal connecting to the active computer by operating the first switch circuit.
This construction allows the third type display device to switch the display screen based on the sync. signal supplied from the active computer, and at the same time, it allows the first switch circuit to couple the active computer with the USB hub circuit.
As discussed above, the first type display device of the present invention allows the switch circuit employing the selector to change the computer. This first type display device thus eliminates the need to re-connect the computer to the USB hub section, and the computer to be used can be selected with ease.
The second type display device of the present invention also allows the first switch circuit employing the selector to change the computer with ease. At the same time, this second type display device allows the second switch circuit to select the display screen proper to the computer to be used.
The third type display device of the present invention selects the display screen based on the sync. signal fed from the active computer, and at the same time, allows the first switch circuit to couple the active computer to the USB hub section. As a result, this third display device can select the active computer automatically, and then operates the display screen as well as peripheral devices. A user thus need not take the trouble to match the display device with the computer to be used.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram schematically illustrating a USB hub circuit of a first type display device in accordance with a first exemplary embodiment of the present invention.
FIG. 2 is a block diagram schematically illustrating a second type display device in accordance with a second exemplary embodiment of the present invention.
FIG. 3 is a block diagram schematically illustrating a third type display device in accordance with a third exemplary embodiment of the present invention.
FIG. 4 is a block diagram schematically illustrating a conventional USB hub circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Exemplary embodiments of the present invention are described hereinafter with reference to the accompanying drawings.
(Exemplary Embodiment 1)
FIG. 1 is a block diagram schematically illustrating a USB hub circuit of a first type display device in accordance with a first exemplary embodiment of the present invention. The USB hub circuit 1 shown in FIG. 1 comprises the following elements:
(a) two pieces of upstream terminals 3 connected to two computers 2 respectively;
(b) a USB hub section 4 ;
(c) a switch circuit 5 disposed between terminals 3 and hub section 4 ;
(d) a selector 6 for operating a switch circuit 5 responding to a selecting request 8 so that the USB hub section 4 can be exclusively coupled to a selected upstream terminal 3 ; and
(e) a down stream terminal 7 for coupling USB compatible peripherals such as a mouse, keyboard 9 and the like to the USB hub section.
In this embodiment, two computers and thus two upstream terminals are employed; however, the numbers of these elements can be more than two.
The USB hub circuit 1 has been coupled with the two computers 2 with the respective upstream terminals 3 that are coupled to the HUB section 4 via the switch circuit 5 . A user selects either one of the two computers 2 before starting a job. The switch circuit 5 is operated by the selector 6 . An operation of the selector 6 by a user upon a need drives the switch circuit 5 to operate a switching function, thereby coupling the USB hub section 4 to, e.g. the second computer that is switched from the first computer. Therefore, if respective downstream terminals 7 are coupled to the USB compatible peripherals such as a keyboard and a mouse 9 , the user need not take the trouble to re-couple the computer 2 with the USB hub section 4 . As a result, the computer 2 to be used can be changed with ease.
The USB hub circuit 1 of the present invention can be integrated into a display device. The display device including the USB hub circuit can effect the same result as discussed above. In other words, the first type display device of the present invention incorporates the USB hub circuit 1 that comprises the following elements:
(a) the switch circuit 5 disposed between the hub section 4 and the plurality of upstream terminals 3 connected to the computers 2 respectively; and
(b) the selector 6 for operating the switch circuit 5 responding to a selecting request 8 so that the USB hub section 4 is exclusively coupled to a selected upstream terminal 3 .
(Exemplary Embodiment 2)
FIG. 2 is a block diagram schematically illustrating a second type display device in accordance with the second exemplary embodiment of the present invention. The same elements as shown in FIG. 1 are denoted with the same reference numbers in FIG. 2 .
The second type display device 11 comprises the following elements:
(a) two pieces of upstream terminals 3 connected to two computers 2 respectively;
(b) a USB hub section 4 ;
(c) a first switch circuit 5 disposed between terminals 3 and hub section 4 ;
(d) two pieces of input terminals 12 receiving video and sync. signals, these terminals are connected to respective computers 2 ;
(e) a video display circuit 13 ;
(f) a second switch circuit 14 disposed between the input terminals 12 and the display circuit 13 ;
(g) a selector 6 for operating the first and second switch circuits 5 and 14 responding to a selecting request 8 so that the USB hub section 4 can be exclusively coupled to a selected upstream terminal 3 as well as the video display circuit 13 can be coupled to a selected video and sync. signal-input-terminal 12 ; and
(h) down stream terminals 7 for coupling USB compatible peripherals such as a mouse, keyboard 9 and the like to the USB hub section 4 .
The numbers of computer 2 , upstream terminals 3 and video and sync. signal-input-terminals 12 can be three or more.
The second type display device 11 is coupled to the two computers respectively via the upstream terminals 3 and video and sync. signal-input-terminals 12 . The upstream terminals 3 are coupled to the USB hub section 4 via the first switch circuit 5 . The video and sync. signal-input-terminals 12 are coupled to the video display circuit 13 via the second switch circuit 14 . The first and second switch circuits 5 and 14 are selected simultaneously by the selector 6 . When a user wants to use the first computer 2 , the user operate the selector 6 to work the first switch circuit 5 , and then the first computer 2 is coupled to the USB hub section 4 . At the same time, the second switch circuit 14 works to couple the first computer 2 to the video display circuit 13 . Therefore, if the USB compatible keyboard and the mouse have been coupled to the downstream terminal 7 , the second type display device 11 can change the peripherals and display screen only by operating the selector 6 . This arrangement eliminates the need to reconnect the computer 2 to the USB hub section 4 or the computer 2 to the video display circuit 13 .
(Exemplary Embodiment 3)
FIG. 3 is a block diagram schematically illustrating a third type display device in accordance with the third exemplary embodiment of the present invention. The same elements used in FIG. 1 and FIG. 2 are denoted with the same reference numbers in FIG. 3 .
The third type display device 21 comprises the following elements:
(a) two pieces of upstream terminals 3 connected to two computers 2 respectively;
(b) a USB hub section 4 ;
(c) a first switch circuit 5 disposed between terminals 3 and hub section 4 ;
(d) two pieces of input terminals 12 receiving video and sync. signals, these terminals are connected to respective computers 2 ;
(e) a video display circuit 13 ;
(f) a second switch circuit 14 disposed between the input terminals 12 and the display circuit 13 ; and
(g) a microcomputer 22 as a controller.
The microcomputer 22 identifies an active computer out of two computers based on a sync. signal supplied through the second switch circuit 14 , and couples the upstream terminal 3 connected to the active computer 2 to the USB hub section 4 by switching operation of the switch circuit 5 . The USB hub section 4 includes the downstream terminals 7 to which peripherals such as a mouse and a keyboard 9 are coupled. The numbers of computer 2 , upstream terminals 3 and video and sync. signal-input-terminals 12 can be three or more.
The third type display device 21 is connected to the two computers via the upstream terminals 3 and video and sync. signal-input-terminals 12 . The upstream terminals 3 are coupled to the USB hub section 4 via the first switch circuit 5 . The video and sync. signal-input-terminals 12 are coupled to the video display circuit 13 via the second switch circuit 14 . This arrangement is the same as that of the second embodiment. When this third type display device 21 is powered on, video and sync. signals supplied from the active computer, e.g. the first computer 2 , run through the second switch circuit 14 and enter into the video display circuit 13 . The microcomputer 22 thus detects that the sync. signal supplied from the first computer 2 has entered to the display circuit 13 .
Then, the microcomputer 22 operates the first switch circuit 5 , whereby the USB hub section 4 is coupled to the upstream terminal 3 connected to the active computer 2 . In this third type display device 21 having the construction as discussed above, when a display screen is changed based on the sync. signal supplied from the computer 2 , the computer 2 is simultaneously coupled to the USB hub section 4 by the switch circuit 5 .
If the microcomputer 22 does not detect a sync. signal when the display device 21 is powered on, the microcomputer 22 operates the second switch circuit 14 and selects another computer. The microcomputer 22 repeats the operation of the second switch circuit 14 until it detects the sync. signal. When the microcomputer 22 detects the sync. signal, it determines that the computer supplying the sync. signal is active, and holds the settings of the first and second switch circuits 5 and 14 as they are. In other words, the third type display device 21 having this construction automatically selects an active computer out of plural computers 2 , and then works the display circuit 13 , the USB compatible keyboard mouse and the like. Thus the process of matching the computer 2 with the display device 21 per se is not required.
The operation discussed above is not limited to when the display device 21 is powered on, but the operation can be practiced arbitrarily upon a user's request. The selector 6 employed in the first and. second embodiments is omitted in the third embodiment; however, the display device can be defined as including the selector 6 so that a user can arbitrarily select one of the computers 2 . | A universal-serial-bus (“USB”) hub circuit includes a switch circuit connected to a USB hub section and a plurality of upstream terminals each of which is adapted to be connected to computers. The USB hub circuit also includes a selector that operates the switch circuit to couple the USB hub section to a selected upstream terminal. A display device incorporates the USB hub circuit. A video sync signal output by an active host computer coupled to one of the upstream terminals determines which upstream terminal is to be coupled to the USB hub circuit. | 6 |
This disclosure is a continuation in part of application Ser. No. 662,149 which was filed on Feb. 28, 1991 and which issued as U.S. Pat. No. 5,153,519 on Oct. 6, 1992, and application Ser. No. 956,632 which was filed on Oct. 5, 1992, now issued as U.S. Pat. No. 5,317,271 on May 31, 1994, and application Ser. No. 176,968 which was filed on Jan. 3, 1994, now U.S. Pat. No. 5,394,092 and also application Ser. No. 201,467, now U.S. Pat. No. 5,394,090 and application Ser. No. 201,469, now U.S. Pat. No. 5,394,091, both filed Feb. 25, 1994.
BACKGROUND OF THE DISCLOSURE
The present disclosure is directed to a system for making several charged species by a pulsed DC spark discharge acting on an inert gas, typically helium, which utilizes the charged species to classify and/or quantify compounds in a gas sample. This detector is connected with upstream or downstream devices such as a sample source, gas chromatography (GC) column, spectrum analyzers, etc. Understanding of various test procedures will illuminate use of the described apparatus and can be gained from review of the apparatus and its mode of operation in a system. A sample to be evaluated is first loaded along with a carrier gas into a system column. The sample passes through this device, a pulsed, high voltage discharge, and several types of detection systems are initiated by this detector. For instance, the very short DC spark creates a readily available thermalized electron flux which can be used in a detection system. In an alternate mode of operation, the spark also creates a more slowly diffused flux of metastable helium atoms which drift toward into a gas sample at a controlled rate. The helium atoms will react with molecules of the gas sample to surrender the excess energy from the excited state to cause sample molecule ionization which, as a secondary reaction, can be measured by a detection system. Another aspect involves transitory photo ionization of a gas into positive and negative charged particles normally recombining at high speed. If a selected bias voltage is applied, the recombination is prevented to furnish a current signal indicative of gas contents.
The preferred form of this system features a pulsed DC spark discharge in the inert gas flow which is followed by a comparably slow metastable carrier gas dispersion and secondary reaction, which is slow in contrast with the practically instantaneous electron initiated interaction the time of the spark. The DC spark discharge therefore enables various detection mechanisms, as will be explained, so that variations in detection electrode geometry and pulse timing can obtain different types of responses. One system uses the highly mobile electron flux while an alternate system relies on the metastable carrier gas molecular energy interchange occurring well after the electron flux. An electron capture detector is set forth. Also, an air monitor is disclosed.
In addition to the particle interaction initiated in the spark manifest in different aspects, there are also two electrode systems responsive to the DC spark. From the spark gap, the electron discharge creates charged species which can be observed at spaced electrodes. Geometry of the spark is sharply defined, narrowly confined, and repetitively located.
This device enables detection of the atomic species in the gas sample. While a first spectrum is formed only during the spark, a second spectral analysis is enabled by the subsequent decay of the metastable helium atoms giving up their excess energy by ionizing molecules of the sample. This interchange occurs as the energized helium atoms diffuse from the spark gap in the test chamber and mix with the sample molecules. Dependent on relative concentrations, diffusion and flow rates, the sample molecules are ionized to emit energy characteristic of the species. This delayed emission is useful in species identification when timely observed, and therefore a different mode of observation is used capture data from this emission. This difference in operation derives primarily from delayed occurrence and is observed at a different time.
The present invention uses to advantage a simple spark gap having a pair of spaced electrodes connected to a current pulse forming system. The pulses are narrow, preferably as small as a fraction of a microsecond. The DC pulses repetitively form precise, sharp and well defined transgap sparks, liberating the electron flux mentioned and also forming the metastable helium molecules. The spark is fixed in size and relative timing, shape and location. Electrode geometry does not erode with time and electron ejection is uniform. Thus, the spark is fixed for observation by spectral analysis. Structurally, this enables a very simple chamber to deploy a pair of opposing, spaced electrodes in a cavity of small volume with gas flow inlet and outlet ports. In a representative system, a chemical sample is mixed with a carrier gas. The sample is prepared for testing by classification, identification or quantification using the detector. An exemplary system achieves separation as a result of differences in travel time through a GC column input to the detector. As is well known, the GC column is either a wall coated open capillary or packed with a stationary phase material so that the carrier gas and the compounds making up the sample are eluated from the GC column. As a generalization, the mobile phase (usually a flowing gas) is delivered by the GC column into this detector for detection of the separated chemical constituents making up the sample.
The detector is operated periodically to test every sample constituent compound passing through the detector. One type of detector used in the past has been the electron capture detector (ECD). The present disclosure sets out an alternate form of ECD detector used in conjunction with a GC column which forms an output signal of substantial sensitivity. The present system features an ECD with a DC pulsed, high voltage spark discharge. As noted at column 2 of U.S. Pat. No. 4,851,683, DC discharges have been known, but they generally have had in homogeneous excitation characteristics and are unstable because of electrode heating and erosion. U.S. Pat. No. 4,509,855 is a DC atmospheric pressure helium plasma emission spectrometer. Additional devices are shown in U.S. Pat. No. 4,866,278. The present apparatus sets forth a DC pulsed, high voltage, spark discharge source which provides a repetitive uniform spark. The spark has a duration which is only a fraction of a microsecond. It would appear theft an acceptable spark duration is a fraction of a microsecond. Moreover, the spark gap is structurally fixed to have a finite width for discharge of the spark created by accumulating energy in a reactive circuit such as a coil and capacitor charging. Preferably, a non-ringing current is applied.
This detector in a representative form includes a means for forming a stabilized spark gap so that the spark and resultant charged particle population are uniform in contrast with the problems referenced in the two mentioned patents. Accordingly, the carrier gas (e.g., carrier flow from the GC column) is directed as a gas flow through appropriate tubing into the spark chamber. An inert gas flows in the spark chamber past a pair of electrodes which are arranged to direct the spark transverse to the inert gas flow. In a first mode of operation, a flux of electrons is obtained. These electrons are quickly dissipated during the spark interval even when spark duration is only a fraction of a microsecond. The number of electrons available can be measured by means of an electrometer connected to electrodes spaced remotely from the spark gap. The electrometer circuitry connected with an electrode in the chamber and spaced from the spark gap detects and measures the electron flux resulting from the spark discharge. In this instance, the spark gas initiates an ECD operation. There is, however, a timed charged particle flux which is delayed after the spark discharge which uses an ionization mode. This involves a delay of up to about 100 or even 200 microseconds after the spark discharge creates ionized molecules which are dispersed at a slower rate compared with the more mobile electron dispersal. The spark disperses highly energized electrons during the spark and also creates a second and slower dispersion of metastable inert gas molecules (preferably helium) after the spark. Charged particle dispersal of the first form is, as a practical matter, instantaneous while metastable helium dispersal is time delayed. The two types of dispersion are readily identified because they involve different types of particles. The dispersal of metastable helium atoms, with an elevated energy state of about twenty or more eV, can be observed at a distance from the spark gap so that sample compound concentration (a scale factor) in the chamber is measured. The metastable helium concentration is useful because it enables this delayed reactions. Thus, the metastable helium atoms react with the sample molecules input with the carrier flow. The high energy in the helium ionizes the sample molecules, creating a measurable current in the chamber.
Building on the last possibility, metastable helium molecules may combine with a trace constituent such as a dopant supplied with t:he inert (helium) gas. One such dopant is nitrogen which, in reaction with the metastable helium, forms nitrogen ions. That causes liberation of electrons which again, because of different mobility, dissipate more readily. Before the electrons recombine with the ionized nitrogen molecules, they will react with the compounds making up the sample flowing through the detector. A connected electrode and electrometer measures electron capture from the dopant involvement to define an electron capture detector.
Another alternate form of apparatus involves observation of the spectrum. This involves the conversion of the certain constituents to elevated energy states where emissions occur at characteristic frequencies, and such frequencies can be observed and measured. This typically involves a spectrum analyzer such as a spectrometer which observes one or more atomic or molecular emission lines in selected regions of the spectrum. Spectral line observation varies with the time relative to the spark discharge. Regarding time, the observed spectrum is different during and after the spark discharge. The present apparatus is therefore summarized as a pulsed DC spark discharge where the spark discharge reacts with an inert gas (preferably helium) to detect compounds in a sample. In this spark, charged particles are created, the particles being either disassociated electrons, an ionized inert gas, ionized dopant gas, or highly energized helium atoms in a metastable form. Depending on the timing of measurements, the particular ionized particles and measurement voltages applied, the device can be operated in an ionization mode, or electron capture mode. Molecules of a compound separated by chromatographic separation or other input devices can be quantified. The device also emits characteristic spectral lines depending on the nature and timing of the emission. Moreover, by selection of the dopant gas, control of pulsing of the spark gap forming the charged particles, timed operation of measurement electrodes, and adjustment of scale factors, it is possible to operate in several modes. In addition to this, precisely defined spectral lines can be observed.
The present apparatus additionally includes simplified versions of the pulse discharge mechanism cooperative with a GC system. In one instance, the helium metastable molecule is used to achieve ionization of the eluate from the GC column without forcing the eluate to flow through the spark gap. This enhances operation of the equipment because the spark acts primarily on helium, while the electrodes are protected from contamination by the solvent or the eluate sample flowing from the GC column. In this version of equipment, the GC column discharge is delivered into the chamber at a location where it is not required to flow through the spark gap. As a second alternative, a dopant gas is input to the detector. Further, this type arrangement enables the system to operate as a simple ionization detector. Alternately, it can be operated as an electron capture detector (ECD hereafter). Details of these structures will be given later. Another aspect of the present apparatus is the use of the device to form an emission spectra which provides spectra from various samples through a transparent window. In this aspect of the system, it is provided with a transparent window sealed at the entrance of a monochromator. In this aspect of the invention, the helium gas flow plus the eluate from the GC column is across the transparent window so that the reaction products do not contaminate the window which loses transparency as a result of impinging contamination. So to speak, the window is located to view the mixing. Through the use of this mechanism spectral emissions can be obtained to analyze the constituent components of a sample. For instance, characteristic atomic, ionic, or molecular spectra lines can be classified. One characteristic of the atomic spectra is formation of extremely narrow emission lines with little or no interference between spectra from other atoms or molecules. This is especially helpful in the vacuum ultraviolet region. By contrast, the ultraviolet and visible regions of the spectra may receive broad interfering spectra from many common elements or molecules. Accordingly, it is especially desirable to operate in the vacuum ultraviolet region and in particular the region of about 120-200 nanometers.
ADVANTAGES OF THE IMPROVED DETECTOR
The present detector is constructed to utilize circular flow patterns within a cylindrical housing. In contrast with the structure set forth in the related disclosures which show linear gas flow through a structure in the preferred embodiments, this preferred embodiment has a cylinder which is constructed with an internal cavity. The flowing carrier gas and eluated molecules from the GC are introduced at a tangent and are directed in a circle. The circular flow enables the detector to segregate particles based on the weight of the molecules. The heavier molecules flow at the outer cylindrical surface and lighter molecules flow at the center of the structure. Rotation is imparted because the inlet carrier gas and eluated molecules from the GC are directed into the structure at a tangent imparting circular or rotating motion. Restated, one aspect and one important advantage of the present system is an arrangement which directs the GC carrier gas and eluated molecules in a circular pathway. This permits the molecules to flow at a relatively fixed distance from the spark gap which is arranged at the center of the cylinder. The heavier eluated gas is segregated away from the spark gap by centrifugal forces thereby minimizing corrosion of the spark electrodes. The spark gap forms the necessary metastable molecules or electron emission which interacts with the eluated compounds. A fixed exposure is achieved. Moreover, the eluated compounds interact with a pair of ring shaped concentric electrodes. These two electrodes function as a bias electrode and a collecting electrode. One is connected with a fixed voltage to provide a bias. The other is connected with an electrometer so that a current flow is established indicative of the concentration of the compound eluated from the GC column.
A further advantage is that circular flow retains eluted gas within the detector for a relatively long period of time when compared with previously mentioned linear flow detectors. This, in turn, yields a more precise and accurate measurement as will be detailed in a following section.
In other aspects, the circular structure is particularly advantageous. It can be used with or connected to an air inlet, not a GC column. It can be used to detect trace gases in the air. As an air detector, a reduced size is then provided. A portable structure is then defined. The structure is particularly advantageous in portable applications such as monitoring fugitive gas discharges which might reach excessive levels in the atmosphere.
In one particular aspect of the present disclosure, the circular detector housing can be made relatively small, having a diameter of up to about 3 or 4 centimeters, and a thickness of approximately 1.5 centimeters or less. The internal cavity is preferably provided with a cylindrical outer wall which creates centrifugal rotation of the gases in the structure. The chamber is ideally maintained at approximately atmospheric pressure. There is no need to make an expensive housing capable of withstanding substantial pressure differentials. A vent is provided out of the chamber, and discharges the chamber which is continuous in operation so long as input gas is delivered to the chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a system showing the cylindrical detector assembly of the present disclosure connected with a GC column and further shows the connected circuits which enable operation to provide several types of output data;
FIG. 2 is a view similar to FIG. 1 showing a side view of the cylindrically shaped detector assembly;
FIG. 3 is a sectional view through the detector assembly in exploded view to show assembly of the collecting electrode and bias electrode and detector housing members which telescope together to form a closed housing; and
FIG. 4 is a side view of one half of the detector housing showing a tangent passage which provides for centrifugal gas rotation within the detector.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present disclosure is directed to an ionization detector system connected with upstream and optional downstream equipment. The cooperative equipment defines one context for ease of explanation so that a thorough discussion of the spark detector system will provide the necessary explanation. This is a detector system devoid of radioactive apparatus and can be used in circumstances where radioactive materials are limited or forbidden. Heretofore, it has been common to operate electron capture devices with radioactive sources, the most common sources being tritium or nickel 63. Typically, these emit beta particles which trigger operation of the electron capture detector or perhaps helium ionization detectors. In this particular instance, a non-radioactive device is thereby provided. Noting FIG. 1 of the drawings, the numeral 20 identifies a detector system of the present disclosure. It will be described proceeding from the input in the fashion of a flow chart, and after that, certain features of the high voltage DC powered pulsed spark discharge system will be discussed, and its interaction with various types of detector systems including charge measuring devices and spectrum analyzers will also be set forth. Certain equations will be given which are believed to correctly describe the nature of the particles of the process. At this stage, the detector will be described with a GC column, and its operation will be given with various inputs.
The present detection system utilizes a carrier gas source 12 connected to the detector with an input valve (not shown). The source provides a carrier gas flow and a sample will be discussed later; there is a constant flow delivered into and through the detector at a controlled pressure and flow rate. Briefly, a carrier gas is supplied in a steady flow rate and pressure. Representative sample compounds may include various and sundry halo carbons and other organics which are carried with the flowing carrier gas. For representative purposes, a specimen of the sample will be denoted very generally as the compound AB, it being understood that the strength or concentration of this is variable. The detector 20 of the present disclosure is able to quantify the compound AB even measuring parts per million, and in some instances parts per billion, and in other instances even smaller concentrations. It is preferable that the sample AB be delivered with argon as the carrier gas. While several gases can be used, the preferred carrier gas is He with argon. Purity will be discussed below. The gas flow is directed to an inlet opening of the plasma detector 20.
A trace element dopant may optionally introduced into the chamber by means which will be described later. A suitable dopant material is N 2 which is provided in a controlled quantity, such as one to one thousand parts per million. A typical range for this dopant can be from one part in 10 3 to one part in 10 9 . The compound AB flows with the carrier gas into the chamber and ultimately interacts charged particles. The spark is formed by current flow at a finite voltage; the spark does not fluctuate because the only mode of current flow is by means of a spark across the gap. The voltage necessary to achieve spark current flow is a function primarily of electrode spacing and tip geometry. The electrode tips are preferably fixed at a known distance from one another so that the voltage necessary to create the spark is fairly stable. Moreover, ambient pressure is maintained in the spark generator 20 so that the voltage does not vary with prevailing pressure. The charging circuit functions like a classic automobile ignition system in that a charging current is provided from a capacitor and coil. When the current flows, resistance breaks to the value required to sustain current flow and current flow then drops the stored electrical charge. Preferably, ringing in the supply circuit is suppressed. It should be noted that the pulse can have a substantial width, ranging down from many microseconds.
When current flows through the gap between the two spaced electrodes, particle excitation occurs. Among other things, elemental helium atoms are energized to become metastable helium and ultimately diffuses from the spark gap in the chamber in a fashion to be described. While a metastable helium atom may have an elevated energy level about twenty eV, it has a fairly long half life, and because of its size, relatively speaking, it diffuses somewhat slowly. The metastable helium atoms will diffuse at some slow rate in all possible directions. This diffusion rate and range can be enhanced depending on housing geometry and detector electrode geometry, placement and voltage. Moreover, when the pulse occurs, there is a substantial electron discharge into the carrier gas atmosphere from the gap, and is quite high. That is, electrons are emitted from and distributed into the immediate atmosphere. These electrons can be observed throughout the detector 20.
There are several equations which are helpful to describe the relatively simple sequence of events occurring in the detector 20. Recall again that flow is circular, diffusion of the charged particles from the spark gap can be initiated and controlled by choice of polarity and potential on the detector electrodes 33 and 35. Indeed, the mobility of electrons :is substantially instantaneous to the extent that electrometer response can be observed promptly even though the spark has a width of less than one microsecond, perhaps a width of only 10 to 300 nanoseconds. The nearly instantaneous diffusion of electrons primarily results from their extreme mobility in comparison with larger charged particles, namely, the metastable helium. Regarding the spark, the voltage across the terminals is typically several thousand volts prior to current flow; once current flow begins, the voltage across the terminals rapidly changes as current flow changes from the initial zero value toward the peak current and then decays. The pulse shape is relatively easy to define at the start of the pulse but it may be difficult to define at the end of the pulse. There are, two reasons for this; the first reason is that the power supply may ring and provide post pulse current reversals. This is preferably suppressed by incorporating means to damp the ringing. A second reason is more subtle, and relates to the ionized particles between the electrodes during the pulse. The resistance across the electrodes may be very low, perhaps so small that it permits current (ionized particles) between the electrodes instantaneously observed at the facing electrodes even though the power supply, at that instant, provides no voltage.
FIG. 2 shows the present detector 20 in a representative GC system which utilizes a sample source 11 and a carrier gas source 12 which are both connected with a loading valve 13. They provide a carrier gas flow at a constant flow delivered at a controlled pressure and flow rate to a 6C column 15. There is a system timer 16 which controls the operation of certain components as will be set forth. Briefly, a carrier gas is supplied in a steady flow for the GC column. Representative compounds include various and sundry halocarbons and other organics which are supplied with the flowing carrier gas through the loading valve 13 to the GC column 15. A specimen of the sample will be denoted very generally as the compound AB, it being understood that the strength or concentration of this is variable. The detector 20 of the present disclosure is able to quantify the compound AB even measuring parts per million, and in some instances parts per billion, and in other instances even smaller concentrations. The discharge of the GC column 15 is directed to the inlet opening 18 of the detector 20.
In FIG. 1, the sample source 11 is input into a loading valve 13. The loading valve switches a selected or quantified portion of sample which is delivered to a GC column 15. The sample is supplied by a carrier gas flow from the source 12. Operation of the loading valve 13 is controlled by a timer 16. As shown in FIG. 1, the GC column provides a discharge which is delivered into the detector 20. There is a tangential inlet port 18. That port is directed to the interior to initiate rotational motion. Discharge is through a vent port 19. These two ports can be arranged opposite each other, and by positioning them at different distances from the center. More will be noted regarding this later. There are two ring shaped electrodes as will be described with respect to FIG. 3. One of the electrodes is the collecting electrode which is provided with a terminal 21. That terminal is connected to the electrometer 28. As better shown in FIG. 2 of the drawings, the terminal 21 connects with one ring electrode while the terminal 22 connects with another electrode which serves as a bias electrode. More will be detailed regarding these in a description of FIG. 3. A B+ supply 34 provides power for various components. Because the system can operate with timed operation, one output from the B+ supply 34 is directed by the timer 16 to a charging circuit 42. The charging circuit operates in conjunction with a high voltage discharge circuit 43 which forms an output current in the shape of a controlled polarity, controlled width and, specified current flow. This is delivered to a first inlet terminal 24 opposite a ground terminal 25. The terminals 24 and 25 provide the DC spark in the interior of the detector 20 as will be described. Preferably, one of the two terminals is hollow. Alternately, it can be constructed with a simple point which is surrounded by an axial passage for delivery of helium from a helium source 26.
Another aspect of the present apparatus, it is shown in both FIGS. 1 and 2 to incorporate a window 27 which enables light to be emitted from the spark, and that is observed by a spectrum analyzer 40. The analyzer 40 provides an output signal to the recorder 41. The light emissions for operation of the device are transmitted out of the system through the window 27. This window is made of material which is impervious to the irradiation created within the detector 20.
Considering now FIGS. 1 and 2 jointly, it will there be observed that a continuous flow of helium is delivered at the center of the detector 20 through the hollow electrode 24. Helium is supplied from the reservoir 26. Dopant may be optionally introduced from the reservoir 26' into the helium flow prior to entry into the detector through the hollow electrode 24. This central input of helium and optional dopant does not cause rotation. Rather, rotation is initiated by the tangential gas flow. This is based primarily on the carrier gas flow from the GC column 15. That gas flow is introduced at a tangent to initiate rotation. Consider now the relative weights of the gases that are introduced. Assume for purposes of discussion that the carrier gas in argon. Argon is heavier than helium. If helium is introduced from the source 26 at a centerline location, it will diffuse radially outwardly only as permitted by the heavier swirling argon carrier gas. If a steady flow of argon is introduced, it will establish rotation in the housing which is a circular flow path. This circular flow path is controlled in velocity by the relative flow rates, the relative size of the detector interior, the difference in the molecular weights of the various gases and by centrifugal forces acting upon the gas molecules. For instance, a heavier carrier gas will rotate with a greater velocity and will tend to stratify, thereby keeping the lighter helium gas toward the center of the housing and the heavier sample gases away from the spark electrodes 24 and 25. This minimizes contamination and corrosion of the spark electrodes. This can be used to advantage so that the flow of helium is relatively small.
Going now to FIG. 3 of the drawings, the detector housing 20 is shown as two cylindrical shell portions. One shell portion 29 incorporates a circular protruding lip 30 which enables the shell half 29 to nest against and join with a second shell portion 31. The shell portions 30 and 31 join together with an overlapping lip arrangement. The two shell portions join together so that a chamber 32 is formed on the interior. The rings for the electrodes are likewise shown. The collecting electrode 21 is connected to a ring 33 while the similar ring 35 is the bias electrode. The two rings are spaced towards the outer cylindrical edge of the circular chamber. The rings are mounted so that they are located in the cylindrical space 32. They are close to each other but there is a gap between the two. As will be understood, the housing portions 29 and 31 are formed of a material of which is not an electrical conductor. Going now momentarily to FIG. 4 of the drawings, the shell portion 29 is again shown and is provided with a tangentially located inlet passage 18. The passage 18 is formed at right angles to the view of FIG. 4. It therefore introduces gas flow just at the interior tangential edge of the cylindrical chamber. As will be observed in FIG. 3 of the drawings, the port 18 is for gas flow introduction. The port 19 is a vent. It can be located radially inwardly as illustrated in FIG. 3. Placement of these two with respect to the radial separation from the centerline axis of the structure and with respect to the two collecting electrodes is a design factor which can be varied so that gas flow in the system can be directed between the two electrodes. The two electrodes can be swapped; they can be located at a common or different radial spacings from the centerline.
DESCRIPTION OF CHARGED PARTICLES AND THEIR REACTIONS
There are several results which occur as a result of the spark discharge through the spark gap. For one, the pulsed spark discharge causes immediate energization of molecules (atoms of helium) in the gap. The mechanism apparently involves collision of the high energy electrons in the spark gap with the helium molecules. In addition to that, molecules (again atoms of helium) in the gap may subsequently emit radiation in a unique spectral distribution characteristic of the excited species and hence form characteristic emission spectra. The several processes occurring during the spark discharge can be summarized by the following five different reactions:
e.sup.- +AB->AB.sup.+ e.sup.- (1)
e.sup.- +AB->A+B.sup.+ +e.sup.- (2)
e.sup.- +AB→AB*+e.sup.- (3)
where AB*→AB+hγ
e.sup.- +AB→A+B*+e.sup.- (4)
where B*→B+hγ
e.sup.- +AB→(AB.sup.+)*+e.sup.- (5)
where (AB + )*→AB + +hγ
where e - denotes a free electron, "*" denotes an atom in an excited state and "+" denotes an ionized atom.
Another reaction which occurs as a result of the pulsed high voltage spark discharge is the conversion of helium into high energy metastable atoms having an energy of about nineteen eV. This reaction is given in Equation 6:
e.sup.- +He→He*+e.sup.- (6)
In the foregoing He* represents the metastable helium atom just as the * above in Equations 3, 4 and 5 represents an enhanced energy level for the particular molecule represented by the symbol AB. In the case of metastable helium, it has a relatively long life, depending on the pressure, and the enhanced energy state has sufficient energy to cause subsequent reactions. Equations 7, 8, 9 and 10 describe selected reactions which can occur involving the metastable helium. As will be understood, the metastable helium extends the duration of the process long after the spark discharge is terminated. In fact, the metastable duration can be hundreds of milliseconds while the spark duration might be only a few nanoseconds. The equations below describe various ionization or excitation results from the metastable helium which results are quite different from those initially caused by the high voltage spark discharge set forth in Equations 1-5 above. Accordingly, Equations 7-10 generally summarize the following reactions resulting from the metastable helium.
He*+AB→AB.sup.+ +e.sup.- +He (7)
He*+AB→A+B.sup.+ +e.sup.- +He (8)
He*+AB→AB*+He (9)
where AB*→AB+hγ
He*+AB→A+B*+He (10)
where B*→B+hγ
Equations 3, 4, 5, 9 and 10 all describe reactions which form specific and characteristic emission spectra, thereby providing a characteristic signal which enables analysis of the emission source. However, one set of spectra will be emitted after the spark in view of the longer decay times involved, for example, in the last four equations above.
Building on this, a sequence of operations will be described. This involves pulsing the high voltage supply to obtain the appropriate narrow pulse so that certain phenomena occur during the spark, and other phenomena occur after the spark, enabling analysis of different emission spectra at different times relative to the spark and its duration. Discussion of these timing factors can also be tied to a discussion of scaling factors relating to particular voltages.
Measurement of a particular charged species is normally made remote from the spark gap. Carrier gas flow in a circle at a specified rate is a scale factor which relates to system sensitivity. Moreover, system sensitivity is controlled by adjustment of the B + voltage (positive or negative) applied to the bias electrode 35. Also, sensitivity is impacted by the radial spacing from the spark gap. Timing is an important scale factor. Consider a typical example. When detecting ions larger than electrons, the detection pulse is applied for a longer interval of time to detect ionic dispersion from the spark gap. Thus, the compound AB forms ionic particles which are measured by periodically pulsing the B + for detection. Assume a pulse of twenty microseconds down 10 to 200 nanoseconds. The spark causes ions to form and the charged particles (less mobile than electrons) drift to the vicinity of the appropriate electrodes. This movement is influenced by the geometry and voltage on the several electrodes. The electric field formed by the two ring electrodes controls charged particle dispersion toward the collecting electrode. The electrometer 28 measures the impingement of electrons at the ring shaped terminal and forms an output current. This can be repeated in cyclical fashion. For instance, the DC pulse can be repeated with a pulse spacing of one millisecond. The compound AB is in the detector chamber for a relatively long period of time due to the circular motion of the flow. Using the relatively long duration in which a compound AB is in the detector system, this assures that the peak will be sampled many times. For instance, assume that the GC column eluate discharges the AB compound over a two second interval. Assume further that the next compound is discharged over a four second interval. Assuming the first eluate transit time through the detector 20 is equal two seconds, over 2,000 samples for that peak will be obtained. The 2,000 data points thus encode the data to assure that proper measurement is obtained and is output to the recorder 41.
As will be observed in the foregoing, the current measured from the charged particles (whether small, highly mobile electrons or larger and less mobile ions) can be timed or gated so that detection of one species can occur during the spark and for a very short duration thereafter, or alternately, long after the spark is terminated. Because of the differences that result during the spark versus the reactions occurring after the spark, the phenomena represented by Equations 1-10 above are different and can be distinguished by observation either of the concentration of electrons or ionized particles or by observation of the different emission spectra. Moreover, the emission spectra is different at different times within the detector. For instance, one emission spectra is observed during the spark and another is observed later.
One valuable benefit of the present apparatus is use of the pulsed high voltage spark discharge as an ionization detector devoid of radioactive sources. This can be done either by using the electron burst during the discharge or the ionization after the discharge resulting from the metastable helium atoms. The ionization initiated responses are thus quite different, and they can be used as a qualitative test of suspected compounds. So to speak, the pulsed system performs as two separate detectors testing the compound AB repetitively, providing two output signals which can be separated and yet which correlate to enhance GC peak analysis.
If desired, the pulsed high voltage spark discharge system 20 can be used in an electron capture detector devoid of a radioactive source. The helium gas can be provided with a dopant gas; the preferred dopant is N2 which creates a relatively high standing current as a result of ionization of the N2. In the event the eluated molecule tends to capture electrons, the standing current flow through the device will decrease in proportion to eluated molecules introduced into the chamber.
Connected upstream and downstream devices are important in use of the detector 20. For instance, in a manufacturing plant, a single compound AB can be tested repetitively. A variety of unknown compounds can be tested with GC separation as mentioned. The present detector can be connected by any suitable supply system to enable testing and quantification of one or more compounds. The detector output is alternately furnished by the current flow from the electrode 27, or is optically determined by the spectrum analyzer. In both instances, the data is potentially different during the pulse and after the spark. This enables an entirely different measurement to be obtained.
One mode of use of the present apparatus is as an ionization detector. In that instance, the bias electrode can be omitted. The collector electrode is provided with negative voltage. A representative voltage might be -100 volts, extending to perhaps -250 volts. A DC voltage is placed on this electrode. In that instance, the structure can be used as an ionization detector.
The structure shown in FIG. 2 can be used in different fashions. Primarily, the differences relate to the voltages which are placed-on the ring electrodes. The electrodes can be made positive or negative. The system thus can be used as an electron capture detector by using illustrated electrodes 33 and 35. Alternately, it can be used in a different fashion simply by disconnecting the electrode 33, or optionally by removing the electrode 33. Operation of the device becomes variable dependent on the interplay of several important factors. One important factor is the position of the GC sample inlet 18. As the tangent angle is varied, sensitivity of the system is also varied. Another important factor is the choice of positive or negative voltage on the terminal 33. This electrode has an influence on the flow of metastable helium which interacts with the introduced gaseous sample. Another factor is the voltage on the electrode 33. Finally, the presence or absence of a dopant gas should be noted. As a generalization, it provides even further: variation in system operation.
The detector 20 is usually operated at ambient temperature, or it can be operated at raised temperatures of up 300° C. The pressure within the chamber is essentially equal to atmospheric pressure. The helium flow typically is less than 10 cubic centimeters per minute. As mentioned, ratios were given for the dopant gas which is added optionally as mentioned. Finally, another scale factor which is varied is the duty cycle of the pulse, and it is varied in accordance with any suitable sequence. The spark is the source of the metastable helium which decays over an interval to provide the necessary energy for interaction with sample molecules and subsequent detection at the electrometer electrode.
IMPROVED OPTICAL MEASURING SYSTEM
The cylindrical shell or housing defines an internal mixing chamber. The housing is formed of material which is opaque to light emissions. It does however have a single shielded window 27. The window is formed of an appropriate material to pass a wave length of interest. The wave length of interest is selected for the region of investigation. As known, the visible light spectrum is approximately 4,000 to 7,000 A°, and that frequency range can be selected. There are reasons to select other frequency ranges; frequency ranges outside the visible spectrum can also be chosen. Appropriate for the frequency range, a particular material is chosen for the window 27 so that it is essentially transparent to that particular frequency range.
A sample of interest is introduced through a GC system and delivered into the chamber 20 through the inlet 18. The GC gas sample mixes with the helium in the chamber 20. The ratio of the sample to the helium is a scale factor which is determined by the flow rates of the sample and the helium. It is also determined in part by the volume of the chamber 20. Suffice it to say, these are scale factors which can be modified to achieve a particular ratio on mixing the sample with the helium gas.
The inlet 18 is tangent to direct the sample flow away from the window 27. The sample typically does interact with the material forming; the window. The electrical spark interacts with the helium and sample to provide optical emissions. They are normally scattered in all directions. Of particular importance to the present apparatus, the optical emissions are observed in the window 27 and are transmitted through the window. The window is able to transmit the optical emissions to the optical measuring device on the opposite side of the window. This is accomplished in the desired fashion so that the optical measuring instrument can observe the emissions and make the necessary measurements. For instance, one form of measurement is detection of the frequency or wave length of particular emissions, and another measurement is the duration and intensity of such emissions. These measurements typically are made by the optical measuring instrument after transmission through the window 27. The window is protected from chemical damage. It is not uncommon that the window surface exposed to the chamber 20 will either become etched or at least smudged with materials derived from the sample in the chamber especially after the sample is highly energized. In this particular instance, the embodiment 20 is configured so that the GC sample is removed from the chamber rather quickly and the exhaustion of any highly activated sample material protects the window 27. It is not unreasonable to suggest daily cleaning of the window in systems where the window is in contact with the sample after it has been energized in the spark. For instance, windows are normally installed for easy removal so that they can either washed or otherwise cleaned for clearing the window of any film or smudge which might obscure optical transmission. Suffice it to say, this type arrangement is protective of the window and enables the equipment to operate with better optical transmission for longer intervals.
While the foregoing is directed to the preferred embodiments, the scope thereof is determined by the claims which follow. | A circular chamber is disclosed. Helium is introduced into the chamber to swirl in a circle to flow past a pair of spaced electrodes forming a spark in the helium. The chamber enables a sample detected by interaction with spark initiated ionization. | 6 |
[0001] This application is a continuation of now pending application bearing Ser. No. 09/587,758, filed Jun. 6, 2000, for “MCIRO CELL ARCHITECTURE FOR MOBILE USER TRACKING COMMUNICATION SYSTEM”, inventors: Donald C. D. Chang et. al, the entire contents of which are incorporated herein by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to communications systems. More specifically, the present invention relates to architectures for data/voice services to mobile users using stratospheric platforms.
[0004] 2. Description of the Related Art
[0005] Stratospheric platforms are being considered for data/voice communication applications. Current proposals envision a mounting of transceivers and antennas on aircraft flying at 20-30 kilometers above the earth which will project beams to cell sites located on the ground.
[0006] Copending U.S. patent application Ser. No. 09/588,395, filed Jun. 6, 2000 by D. Chang et al., entitled STRATOSPHERIC PLATFORM BASED MOBILE COMMUNICATIONS ARCHITECTURE, the teachings of which are incorporated herein by reference, addressed the need in the art for a stratospheric platform based communication system offering maximum throughput with the constraints of weight, power and spectrum. In accordance with the teaching of the referenced patent application, communication between users and external networks is facilitated through stratospheric platform and a hub located on the ground. Beamforming is performed at the hub. Signals to and from the user are communicated via directional beams through a phased array antenna on the platform under the directional control of the hub.
[0007] Although this system offers a promising solution to the need in the art for a stratospheric platform based communication system and method for projecting beams of varying cell structure to maximize system capacity within the weight, power and bandwidth constraints thereof and thereby optimize the projection of beams with adequate link margin for billable voice and data transmissions, a further need exists in the art for a system and method for tracking the position or location of a user.
[0008] For certain applications, the ability to track the position or location of the user would allow for more relaxed platform stability requirements and thereby lower the overall costs of the system. One such application is that of the ‘third generation mobil’ communications system. As a stratospheric platform application (SPA) this system would provide high data rate communications to a user enabling simultaneous voice, data and entertainment communication. For a lightweight platform payload, both the transmit power and the antenna aperture can be limited. To close a communication link, a larger aperture is needed for the receive end onboard the platform and a larger aperture and more powerful high power amplifiers are needed for the transmit end as well. These requirements are in direct conflict with the objective of a lightweight payload. With beams tracking the mobile users so that the users are always at the antenna peak directivity or within a contour of 1-dB from the peak, the link would have a 3 to 4 dB advantage over the fixed beams.
[0009] In addition, since beams would be tracking users, there would be no need to form beams where no users are present except for a new acquisition beam that may scan or a big beam that may be used to zoom in. This arrangement may also save beam forming computations depending on the distribution of users.
[0010] In addition, when beams are formed around each user, there may be more opportunities to reuse either the code division multiple access (CDMA) codes or the carrier frequency thereof. This would result in higher system capacity for a limited spectrum.
[0011] Knowledge of the user location would also allow for fewer CDMA code handoffs. In a fixed-cell-structured system, when a user crosses a boundary of two cells, CDMA code handoff must happen to avoid interference. With a beam following a user scheme, the user would not have to change his CDMA code unless he gets to close to another user who is using the same CDMA code. (A code assignment algorithm is a subject of a copending U.S. patent application Ser. No. 09/735,861 entitled A DYNAMIC CELL CDMA CODE ASSIGNMENT SYSTEM AND METHOD, filed Dec. 12, 2000 by Ying Feria et al.)
[0012] Hence, a need exists in the art for a system and method for tracking the position or location of a user in a stratospheric platform based communication system.
SUMMARY OF THE INVENTION
[0013] The need in the art is addressed by the system and method for user tracking of the present invention. The inventive system is adapted for use in a wireless communication system and creates a plurality of beams within a coverage area. A first beam is directed at a user in a first microcell and a number of additional beams illuminate microcells immediately adjacent the first microcell. The system is equipped with a mechanism for detecting movement of the user from the first microcell to one of the immediately adjacent microcells. On the detection of movement of the user, the system redirects the first beam from the first microcell to a second microcell, the second microcell being one of the adjacent microcells.
[0014] In the illustrative embodiment, the system is implemented in a stratospheric platform based communication system including a hub adapted to communicate with a stratospheric platform. A transceiver and a phased array antenna are disposed on the platform to communicate with the hub and with the user. A second antenna is provided on the platform to communicate with the hub. Beamforming and direction are implemented on the hub and communicated to the platform. The user's position is detected with a global positioning system receiver, by measuring the strength of a signal received from the user, or by other suitable means. On detection of user movement from the first microcell, the beamforming system redirects the beam to follow the user into a second microcell. Additional beams around the user's microcell are illuminated to facilitate detection of the users movement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a diagram illustrative of the stratospheric communication system of the present invention with a single stratospheric platform.
[0016] [0016]FIG. 2 is a simplified block diagram of the airborne platform based transceiver system implemented in accordance with the present teachings.
[0017] [0017]FIG. 3 is a simplified block diagram of a hub in accordance with the teachings of the present invention.
[0018] [0018]FIG. 4 is a functional block diagram illustrative of the forward processing of the hub in accordance with the present teachings.
[0019] [0019]FIG. 5 is a functional block diagram illustrative of the forward processing of the platform in accordance with the present teachings.
[0020] [0020]FIG. 6 is a functional block diagram illustrating the processing at the user location in accordance with the teachings of the present invention.
[0021] [0021]FIG. 7 is a functional block diagram illustrating the return path processing performed on the platform in accordance with the teachings of the present invention.
[0022] [0022]FIG. 8 is a functional block diagram illustrating return path processing at the hub in accordance with the teachings of the present invention.
[0023] [0023]FIG. 9 is a diagram which shows how nonuniform cells are created with a fixed platform antenna aperture.
[0024] [0024]FIG. 10 is a set of graphs showing spreading angle as a function of distance from the projected platform location to a user of an elevated beam projection system.
[0025] [0025]FIG. 11 is a block diagram of an illustrative implementation of a code assignment algorithm for use in connection with the communication system depicted in FIG. 1.
[0026] [0026]FIG. 12 is a diagram that illustrates color code assignments based on the number of users in accordance with the method of the present invention.
[0027] [0027]FIG. 13 shows a color 1 code assignment (blue) in accordance with the teachings of the present invention.
[0028] [0028]FIG. 14 shows a color 2 code assignment (pink) in accordance with the teachings of the present invention.
[0029] [0029]FIG. 15 shows a color 3 code assignment (orange) in accordance with the teachings of the present invention.
[0030] [0030]FIG. 16 shows a color 4 code assignment (purple) in accordance with the teachings of the present invention.
[0031] [0031]FIG. 17 depicts an overall code assignment.
[0032] [0032]FIG. 18 is a diagram illustrating a distribution of users sharing a code division multiplexed (CDMA) code in accordance with the teachings of the present invention.
[0033] [0033]FIG. 19 is a diagram showing an illustrative microcell architecture for use in the mobile user tracking system of the present invention.
[0034] [0034]FIG. 20 is a magnified view of a portion of the diagram of FIG. 19 showing overlap between microcells in accordance with the present teachings.
DESCRIPTION OF THE INVENTION
[0035] Illustrative embodiments and exemplary applications will now be described with reference to the accompanying drawings to disclose the advantageous teachings of the present invention.
[0036] While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
[0037] [0037]FIG. 1 is a diagram illustrative of the stratospheric communication system of the present invention with a single stratospheric platform. The inventive system 10 includes a transceiver system 20 mounted on an airborne platform (not shown). In practice, the platform could be an airplane flying in an orbit at 20-30 kilometers (km) above the ground. Those skilled in the art will appreciate that this altitude is 2 to 3 times that of commercial aircraft (i.e., 10 km) and much lower than the altitude of a low earth orbit satellite (1000 km). The transceiver 20 is adapted to communicate with a hub 30 and a plurality of users 40 and 50 located on cells 60 and 70 , respectively, on the earth's surface. This system is described and claimed in copending application entitled STRATOSPHERIC PLATFORM BASED MOBILE COMMUNICATIONS ARCHITECTURE, Ser. No. 09/588,395, filed Jun. 6, 2000, by D. Chang et al., the teachings of which are already incorporated by reference.
[0038] [0038]FIG. 2 is a simplified block diagram of the airborne platform based transceiver system implemented in accordance with the present teachings. The system 20 includes a feeder antenna 22 adapted to receive a signal from the hub system 30 . The feeder antenna at C, X or other suitable frequency band. The antenna 20 is connected to a radio frequency (RF) downconverter circuit 24 . The downconverter 24 is adapted to downconvert signals received by the antenna. Hence, a C band antenna would be coupled to a C-band RF downconverter 24 . The downconverter 24 outputs a signal at baseband which is demultiplexed by a code division multiplexer 26 into plural separate signals of which 192 are shown in the figure. The multiplexer 26 is bi-directional and serves to multiplex plural signals into a single signal when the system 20 is operating as a receiver. Those skilled in the art will appreciate that the system shown in FIG. 2 is intended for illustration only. Accordingly, the present teachings are not limited to the number of channels or elements shown. Nor is the system limited to the specific circuit configuration shown. Other circuit configurations may be used without departing from the scope of the present teachings.
[0039] The demultiplexed signals feed an RF upconverter 28 . In the illustrative embodiment, the upconverter 28 operates at S-band. The upconverter drives a phased array antenna 29 . As discussed more fully below, the antenna 29 is a single aperture antenna that transmits and receives multiple output beams. The beams are formed and steered by a beamforming network located on the surface in the hub system 30 . Each beam creates a footprint on the surface that provides a cell such as the cells shown at 60 and 70 in FIG. 1.
[0040] As discussed more fully below, the present invention allows the cell size to be non-uniform. That is, at center of coverage, or nadir, the cell can be smaller. As the scan angle increases, the cell sizes increase. The invention allows for a very light weight payload design and full utilization of the resources that a light-weight payload can offer. The present invention forms beams where there are users present with beams of shapes and sizes that are not necessarily uniform. One or more wider beams are formed to provide links supporting lower data rates. These lower data rate links are used to pick up new users trying to get on the system. This allows the coverage area to be greater with limited receiving beams. In addition, by allowing the beam size to be smaller at the center of coverage (nadir of the platform), the code or frequency reuse distance can be reduced, therefore enhancing the total system capacity.
[0041] [0041]FIG. 3 is a simplified block diagram of a hub in accordance with the teachings of the present invention. The hub transceiver system 30 includes an antenna 32 adapted to communicate with the antenna 22 on the airborne platform. The antenna 32 connects to an RF subsystem 34 which provides upconversion and downconversion in a conventional manner. The subsystem 34 receives a baseband signal from a code division multiplexer/demultiplexer 36 . The multiplexer 36 receives inputs from a digital beam former 38 which is fed by conventional multiplexers/demultiplexers, routers, and formatters 39 . The multiplexers/demultiplexers, routers, and formatters 39 are connected to an external network such as the Internet or World Wide Web.
[0042] The systems depicted in FIGS. 2 and 3 may be implemented in accordance with the teachings of U.S. Pat. No. 5,903,549, issued May 11, 1999 to Von Der Embse and entitled Ground Based Beam Forming Utilizing Synchronized CDMA, the teachings of which are hereby incorporated by reference herein. The number of beams (or simultaneous users) ‘n’ is scaleable at the gateway.
[0043] In accordance with the present teachings, the beam forming circuit 38 generates phasings, weightings and codes for each of a plurality of beams. These beams are multiplexed into a single stream which is transmitted up to the airborne platform 20 via the link provided by the feeders 22 and 32 of FIGS. 2 and 3 respectively. When the stream is received on the airborne platform, it is demultiplexed into separate feeds for the array antenna 29 . The phasing and weighting of the signals provided by the beamforming circuit 38 are effective to generate the plural beams and to steer each beam in a desired direction.
[0044] FIGS. 4 - 8 illustrate the operation of the present invention with respect to forward processing, i.e., from the external network to a user, and return processing, from the user to the external network.
[0045] [0045]FIG. 4 is a functional block diagram illustrative of the forward processing of the hub in accordance with the present teachings. In the illustrative embodiment of the hub processing system 30 , user data is received from one or more Internet Service Providers (ISPs) and directed to circuitry associated with each user by a multiplexer 39 . FIGS. 4 - 8 have been simplified to show circuitry associated with a single user. It will be understood that data directed to each user will be processed in a manner similar to that depicted in FIGS. 4 - 8 .
[0046] Returning to FIG. 4, the multiplexer 39 is adapted to process signals returning to the hub 30 as discussed more fully below. The signal for a single user is selected by the multiplexer 39 and directed to a code division multiple access (CDMA) encoder/decoder 41 . While the encoder/decoder may be implemented in software, in the illustrative embodiment, the encoder/decoder 41 is a digital signal processor which employs a well-known CDMA coding scheme such as an orthogonal (Walsh) code, Gold code and/or Viterbi code to spread the incoming data with a user code. This increases the bandwidth of the incoming signal and allows for a superimposition of signals without interference. The user code is supplied by a dynamic database 43 which performs a lookup of a user code in response to the input of a user ID. The user ID may be supplied by a system controller 45 which performs numerous housekeeping functions in response to input from a system manager interface 47 . For example, the controller 45 is programmed to initialize new users and set up the links therefor. In addition, in accordance with the present teachings, the controller 45 is programmed to recognize conflicts and reallocate codes for certain users as necessary in the manner discussed more fully below.
[0047] A spread user signal is output by the encoder/decoder 41 to a digital beam former 38 . The beam former 38 is a conventional beam forming system which provides element phasing information to direct a beam containing the spread user signal and amplitude information to shape each beam for each user. These beam formed user signals are summed by an adder 37 and input to a CDMA antenna element spreading encoder 36 . In the illustrative embodiment, the element spreading encoder 36 uses orthogonal codes to spread the signal for each element in response to an element code supplied by a register or memory 35 . The user signals might be on the order of 144 kilobits per second bandwidth, spread to 5 megahertz by the encoder 41 , and spread further to 0.5 to 1 gigahertz by the element spreading encoder 36 . The signals from the elements are summed by a second adder 31 and input to the radio frequency stage 34 . In the illustrative embodiment, the RF stage is an RF transceiver which outputs a right-hand circular (RHC) signal in the C-band or X-band range. In practice, a second identical circuit 30 ′ (not shown) would output a left-hand circular (LHC) signal as well. These signals are combined at the antenna 32 and uplinked to the platform 20 depicted in FIG. 1.
[0048] [0048]FIG. 5 is a functional block diagram illustrative of the forward processing of the platform in accordance with the present teachings. As shown in FIG. 5, the uplinked signal is received by a feeder antenna 22 and fed to LHC and RHC processing circuits 20 and 20 ′ of which only the LHC circuit 20 is shown. Each processing circuit 20 includes an RF transceiver 24 which downconverts the (C-band) uplink feed of one polarization and outputs feeder signals for each antenna element. The element signals are despread by an element decoder 26 in accordance with a code stored in a memory 51 associated with each element. A signal for a given element is upconverted to S-band, in the illustrative embodiment, and combined with the corresponding signal output by the processing circuit 20 ′ for the RHC by a summer 27 which outputs an element downlink signal to a phased array antenna 29 . The phased array antenna 29 forms one or more beams in response to the phasings and weights originally impressed on the element downlink signal by the hub-based beam forming processor 38 of FIG. 4. The beams are thereby directed to an associated user. FIG. 6 is a functional block diagram illustrating the processing at the user location in accordance with the teachings of the present invention. The signal transmitted by the platform is received by an antenna 52 and downconverted into first and second bands by an S-band RF transceiver 54 . One band is selected by the user via an interface 53 . The selected signal is despread by a CDMA decoder 56 which is adapted to decode the signal in accordance with the encoding scheme employed by the encoder 41 of FIG. 4. The decoder 56 outputs a user signal in response to a user code supplied by a memory 55 .
[0049] The return path processing begins with user data being supplied to a summer 64 which combines the user data with location data supplied by a conventional global positioning system (GPS) receiver 62 . The combined signal is spread by a CDMA encoder 58 , which, in the illustrative embodiment, is designed to operate in accordance with the encoding scheme employed by the encoder 41 of FIG. 4. The encoded signal for the selected band is upconverted (to S-band in the illustrative embodiment) and transmitted to the platform 20 via an antenna 68 .
[0050] [0050]FIG. 7 is a functional block diagram illustrating the return path processing performed on the platform in accordance with the teachings of the present invention. The signal from the user is received by the phased array antenna 29 and downconverted by the RF transceiver 28 . The transceiver 28 outputs an element return signal to an encoder 26 . The encoder 26 spreads the signal to avoid interference with the uplink signal and outputs a spread element return signal. The spread element return signal is combined with platform location data supplied by another conventional GPS receiver 55 which is spread by an encoder 56 in response to a code stored in a memory 59 . The spread element return signal and the spread GPS location data are combined with corresponding signals from other elements by a summer 53 and upconverted to C-band before being downlinked to the hub 30 via the antenna 22 .
[0051] [0051]FIG. 8 is a functional block diagram illustrating return path processing at the hub in accordance with the teachings of the present invention. The signal downlinked from the platform is received by the antenna 32 and separated into RHC and LHC downlink feeds. Each feed is downconverted to IF by the C-band RF transceiver 34 . The downconverted signal is despread by the CDMA decoder 36 . The element returns for each user are processed by the beamforming processor 38 in response to the stored phases and weights supplied by the database 47 . The spread user data is then supplied to the CDMA decoder 41 which decodes the data in response to a user code supplied by the database 47 . The decoder 41 outputs user data suitable for transmission over the network connected to the multiplexer 39 .
[0052] In the preferred embodiment, each beam is assigned to a user or a zone. If assigned to a user, the beam is adapted to move with the user to minimize the number of code handovers and to increase antenna directivity in user links. Static beams are formed where no user tracking beams are present for new user detection.
[0053] Conventionally, the beams radiated by the antenna 29 of FIG. 2, would be constrained to provided fixed, uniform footprints or cells on the ground. If the user distribution is uniform, the equal sized cell structure is optimal. However, equal cell size comes at some cost in hardware. To avoid the need for a mechanical tracking system on the antennas, which can be costly and unreliable, the antennas are phased arrays of radiating elements and steered electronically. At a certain altitude from the ground, where a payload carrying platform locates, a same-sized ground projection cells require smaller angular beams as the scan angle increases. To form smaller beams, more antenna array elements will be needed. For a lightweight payload, the number of elements may be limited, thus forming smaller beams at the edge of the coverage may be costly.
[0054] However, in accordance with the present teachings, the beams are formed without regard to a fixed uniform pattern by the digital beam forming network 38 . The system 10 is designed to cover a service area with as many users as possible. If the cell size is uniform on the ground, then the required number of elements in the phased array antenna would be so high that a light-weight payload would not be possible. On the other hand, if some elements are not being utilized to form wider beams at the center of the coverage (or nadir of the platform), the resource (frequency or code) reuse distance would be longer. This would result in fewer users on the system and lower total system capacity.
[0055] Consequently, the system 10 of the present invention is designed with a dynamic cell structure utilizing all the resources available on a light-weight payload to form beams as small as possible and reuse the frequency or CDMA code as often as possible to enhance the total system capacity. That is, the system 10 allows the cell sizes to be non-uniform. At center of coverage, or nadir, the cell can be smaller. As the scan angle increases, so does the cell size. In addition, the cell shape is not restricted to be perfectly circular. The cell shape may be elongated as the scan angle increases. This is depicted in FIG. 9 below.
[0056] [0056]FIG. 9 is a diagram which shows how nonuniform cells are created with a fixed platform antenna aperture. The scenario illustrated in this figure assumes a nominally circular antenna array situated at ‘A’ and oriented normal to the local vertical. The antenna is at an altitude ‘h’ above the ground point ‘O’, which is at the center of the coverage area. Now consider the beam formed by this antenna having maximum directivity in the direction of a user located at point ‘C’. Assuming that differential spreading of the antenna gain across the beam width can be neglected, the contour of constant antenna gain on the ground plane, denoted ‘BDEF’ in the figure, will be elliptical in form. Furthermore, the long-side spreading (∠CAD and ∠CAB) will be equal, as will the short-side spreading angles (∠CAE and ∠CAF). The distances CB, CD, CE, and CF can be easily calculated as
CB h = tan ( ∠ OAC + [ long-side spreading-angle ] ) - tan ∠ ( OAC ) CD h = tan ( ∠ OAC ) - tan ( ∠ OAC - [ long-side spreading-angle ] ) CE h = CF h = 1 cos ( ∠ OAC ) tan ( [ short-side spreading-angle ] )
[0057] Assuming the antenna aperture is constant, the spreading angles are then a function of the distance between a user and the projected platform location on the ground (OC). The larger the OC is, the larger the spreading angles are, as shown in FIG. 10.
[0058] [0058]FIG. 10 is a set of graphs showing spreading angle as a function of distance from the projected platform location to a user of an elevated beam projection system. Note that the short-side spreading angle may be different from the long-side spreading angle.
[0059] In practice, optimal utilization of system resources calls for multiple (e.g. 200) beams to be generated. As mentioned above, in the preferred embodiment, each beam would track a user if a user were present. To maximize system capacity, the frequencies are reused by assigning codes to each beam.
[0060] In the illustrative implementation, a group of 64 codes is divided into 4 subgroups. Each subgroup of codes is referred to as one color of codes and has 16 individual codes. In the illustrative embodiment, there are four colors of codes. The assignment of one color of codes is independent of the other colors of codes. The same color of codes can be reused outside a criterion. In the illustrative embodiment, a 20 decibel (dB) sidelobe contour criterion is employed. In accordance with this criterion, a beam collision will be detected when the user moves into another cell and receives a signal therein at a level of 20 dB down from maximum or higher. The 20 dB sidelobe contours can be of different sizes and shapes throughout a coverage area.
[0061] [0061]FIG. 11 is a block diagram of an illustrative implementation of a code assignment algorithm for use in connection with the communication system depicted in FIG. 1.
[0062] [0062]FIG. 12 is a diagram that illustrates color code assignments based on the number of users in accordance with the method of the present invention. The method 100 includes the step of assigning codes with as many colors as possible ( 110 ). Next, the code colors are sorted with the number of users in descending order (step 120 ). Hence, as shown in FIG. 12, purple 122 might be used for 5 users, orange 124 might be used for 10 users, pink 126 might be used for 25 users and blue 128 might be used for 30 users.
[0063] Returning to FIG. 11, at step 130 , if a new user enters a cell, the system checks to determine if the new user can be assigned to the first code color using the 20 dB sidelobe contour criterion. If not, at step 140 , the system 10 tries the next color. At step 150 , the system endeavors to find a code in the code color and at step 160 , the code is assigned to the user.
[0064] Illustrative code assignments are shown in FIGS. 13 - 17 .
[0065] [0065]FIG. 13 shows a color 1 code assignment (blue) in accordance with the teachings of the present invention.
[0066] [0066]FIG. 14 shows a color 2 code assignment (pink) in accordance with the teachings of the present invention.
[0067] [0067]FIG. 15 shows a color 3 code assignment (orange) in accordance with the teachings of the present invention.
[0068] [0068]FIG. 16 shows a color 4 code assignment (purple) in accordance with the teachings of the present invention.
[0069] [0069]FIG. 17 depicts an overall code assignment. As shown in FIG. 13, each cell 70 is created by a beam directed to a respective user 50 . Note that although the beams overlap, no two beams overlap a user. This is depicted in FIG. 18.
[0070] [0070]FIG. 18 is a diagram illustrating a distribution of users sharing a code division multiplexed (CDMA) code in accordance with the teachings of the present invention. At anytime, a user would not be located inside the contour of another user using the same code. In FIG. 18, the stars are the users. The oval shaped contours are the isolation forbidden zone. That is, any other user using the same code cannot locate inside the forbidden zone. As in the figure, for each oval contour, there is only one user locate in the center of the contour. FIG. 18 shows the code sharing to one of the CDMA codes. For each different code, a similar figure can be drawn.
[0071] Returning to FIG. 8, the beamforming processor 38 utilizes the GPS location data in the return signal with respect to the coordinates of the platform and the coordinates of the user to generate beam direction control signals for each user. In accordance with the present teachings, each coverage area or cell, is subdivided into a plurality of microcells. This is depicted in FIG. 19.
[0072] [0072]FIG. 19 is a diagram showing an illustrative microcell architecture for use in the mobile user tracking system of the present invention. As shown in FIG. 19, the architecture is implemented within a cell 200 as a plurality of microcells #1-61 with precomputed beam weights. In the illustrative embodiment, the microcells correspond to <1 dB antenna directivity roll-off from the peak. The present teachings are not limited to the size and shape of the microcells shown. A variety of shapes and sizes may be used to create uniform or nonuniform patterns without departing from the scope of the present teachings.
[0073] In accordance with the present teachings, for a user located at microcell #7 a finite number of beams is formed around the user (e.g. at microcells #1, 2, 6, 7, 8, 13 and 14). So long as the user remains in microcell #7, the beam direction is unchanged. However, if the user moves to microcell #8, then the signal received from microcell #8 will be greater than the signal received from microcell #7. At this point, narrow beams are shifted from microcells #1, 2, 6, 7, 8, 13 and 14 to microcells #2, 3, 7, 8, 9, 14 and 15. In short, in accordance with an illustrative embodiment of the present teachings, a narrow beam is directed to the cell at which the user is located based on strongest return signal, GPS location or other information and to an area surrounding the user defined as microcells in the preferred embodiment. The system continues to track the user as the user travels from microcell #7 to microcell #59 as depicted in FIG. 19.
[0074] For mobile users, the beam weights would have to be updated on some basis. For example, assuming a user is moving at a speed under 120 km/hr, and a beam size (with a 4-dB rolloff) of 8 km, the beam weight update rate of approximately once every minute might be adequate. As the user moves along a boundary between microcells, he may be registered with one cell, then another, then back to the original cell. This ‘ping-pong’ effect may be mitigated by overlapping the cells as depicted in FIG. 20.
[0075] [0075]FIG. 20 is a magnified view of a portion of the diagram of FIG. 19 showing overlap between microcells in accordance with the present teachings. With the overlap between adjacent cells, a user will not be assigned to a new microcell immediately when he enters a new microcell's boundary. On the contrary, a new microcell assignment will occur when the user leaves the area of the old cell completely.
[0076] Thus, the present invention has been described herein with reference to a particular embodiment for a particular application. The present teachings allow for a very light weight payload with full utilization of the resources that a light-weight payload can offer. Those having ordinary skill in the art and access to the present teachings will recognize additional modifications, applications and embodiments within the scope thereof.
[0077] It is therefore intended by the appended claims to cover any and all such applications, modifications and embodiments within the scope of the present invention.
[0078] Accordingly, | A system and method for tracking a user. The system is adapted for use in a wireless communication system and creates a plurality of beams within a coverage area. A first beam is directed at a user in a first microcell and a number of additional beams illuminate microcells immediately adjacent the first microcell. The system is equipped with a mechanism for detecting movement of the user from the first microcell to one of the immediately adjacent microcells. On the detection of movement of the user, the system redirects the first beam from the first microcell to a second microcell, the second microcell being one of the adjacent microcells. In the illustrative embodiment, the system is implemented in a stratospheric platform based communication system including a hub adapted to communicate with a stratospheric platform. A transceiver and a phased array antenna are disposed on the platform to communicate with the hub and with the user. A second antenna is provided on the platform to communicate with the hub. Beamforming and direction are implemented on the hub and communicated to the platform. The user's position is detected with a global positioning system receiver, by measuring the strength of a signal received from the user, or by other suitable means. On detection of user movement from the first microcell, the beamforming system redirects the beam to follow the user into a second microcell. Additional beams around the user's microcell are illuminated to facilitate detection of the users movement. | 7 |
TECHNICAL FIELD
[0001] The invention relates to a connecting device in accordance with the preamble of claim 1 .
PRIOR ART
[0002] In order to erect load-bearing structures of a building constructed from precast concrete parts, the precast concrete parts have to be force-transmitting-connected with one another. Plate-shaped wall elements are connected to one another or to vertical columns at vertical joints. Corresponding casting channels are disposed at the end faces of the elements, on the base of which connecting elements with storage boxes are arranged, which contain reinforcing members that can be folded out. These reinforcing members can be made, for example, of concrete reinforcing bars. Such a so-called bend-back connection is disclosed, for example, in document DE 39 37 275 A1, however it has the disadvantage that the bending back of the concrete reinforcing bars is cumbersome and power-consuming and requires sturdy storage boxes with large dimensions.
[0003] In a different concept, the reinforcing members can also be configured as flexible rope elements. Such storage boxes are disclosed, for example, in WO 03/008737, EP 0 914 531 A1 or EP 0 534 475 A1. By folding out these flexible rope elements, loop-shaped members are provided perpendicular to the end face, which overlap one another in the joint when the precast members are assembled. The loops which overlap one another in the joint are filled in the casting joint with casting mortar for the most part over the entire height of the precast members. Following hardening of the casting mortar, the casting joint is able, due to the overlapping connecting elements, to transmit forces in different directions, i.e. on the one hand to transmit tensile forces in the overlap perpendicular to the joint, i.e. perpendicular to the end face of the precast members, and on the other hand to transmit shear forces perpendicular to the plate plane and, particularly importantly, to transmit shear force parallel to the longitudinal direction of the joint. The latter represents a load case that occurs very frequently in construction practice.
[0004] However, in contrast to the storage boxes with rigid reinforcing members (concrete reinforcing bars) as described above, the flexible rope elements only indirectly contribute to the transmission of shear forces since although they counteract an expansion of the connecting joint, they are, however, only able to develop small force components in the shear force direction owing to their flexibility.
SUMMARY OF THE INVENTION
[0005] It is therefore an object of the present invention to provide a connecting device of the type described above, which has at least one flexible reinforcing loop element and an improved shear load-bearing behaviour at the same time as a simple structure.
[0006] This object is solved according to the present invention by a connecting device having the features of claim 1 . Advantageous further developments of the invention are specified in the dependent claims.
[0007] The idea forming the basis for the invention is to improve the shear load-bearing behaviour by means of an optimised interlocking between the storage box of the connecting device and the surrounding concrete and to reduce the load of the wall component to the side of the storage box. For this purpose, it is provided according to the invention that the bottom of the storage box has bottom profiling with groups of bottom projections and bottom depressions alternating in the longitudinal direction, with each group having at least one bottom projection or at least one bottom depression.
[0008] Owing to the alternating arrangement of the bottom projections and bottom depressions, a good overall interlocking results between the bottom of the storage box and the concrete, which can be achieved with comparatively little production effort, in particular comparatively low degrees of deformation when forming the bottom projections and bottom depressions. The good overall interlocking leads to it being possible to introduce shear force loads into the respective concrete part with little slip via the bottom of the storage box such that the force transmission via the connecting device can be activated before distinct crack formation occurs in the concrete. The shear force is furthermore introduced via the bottom of the storage box at a position in the concrete part at which it is no longer weakened by the joint. An often critical breaking-off of component flanks in the region of the joint is minimised in this manner.
[0009] The design of the bottom of the storage box not least also acts favourably on the transmission of force within the joint itself, i.e. between the casting mortar, the flexible reinforcing loop elements and the storage box. The load-bearing behaviour in this area can be theoretically reproduced by a strut-and-tie model with tension ties and compression struts (even though the present invention is not restricted at all by this model). Shear forces parallel to the joint and the transmission thereof via the casting joint leads to compression struts that extend at an angle from the bottom of the storage box and side walls, which are supported on the respective opposite storage box. This support of the inclined compression struts that are important for the load-bearing behaviour is clearly improved by the design of the bottom of the storage box with alternating projections and depressions. At the same time, the flexible reinforcing loop elements ensure that the force component generated by the inclined compression struts, which tends to expand the joint, is accommodated and transmitted.
[0010] As has been shown in extensive tests and analyses, an optimal combination of overall interlocking and/or shear load-bearing behaviour with simple producibility results if, according to a further development of the present invention, the bottom projections and bottom depressions each have a maximum height, with the total height of the bottom depressions and bottom projections of adjacent groups defining a total depth of interlock that is in the range of 3 to 9 mm, preferably 5.5 to 6.5 mm. It is thereby particularly preferred for the bottom projections and bottom depressions to have substantially the same height, i.e. for example, if the total depth of interlock is 6 mm, they each have a height of 3 mm. When producing the storage box, this results in a particularly low and uniform degree of deformation of the bottom depressions and projections, whilst a uniform load-bearing behaviour is at the same time established on both the inside and outside of the bottom of the storage box. This effect, as will be discussed in more detail below, is more pronounced the smaller the distance between the bottom projections and depressions.
[0011] According to a further aim of the present invention, it is provided that the side walls of the storage box each have a wall profiling with groups of wall projections and wall depressions alternating in the longitudinal direction, with each group having at least one wall projection or at least one wall depression. The overall interlocking between the storage box and the casting mortar in the joint on the one hand and the concrete of the structural part on the other hand can be further improved in this manner, with an improved load-bearing behaviour resulting in particular in the case of a shear force load in the longitudinal direction of the elongated storage box.
[0012] In the aforementioned tests and analyses, the inventors determined that a particularly advantageous combination of shear load-bearing capacity and simple producibility of the connecting device results if, in accordance with a further development of the present invention, the wall projections and wall depressions each have a maximum height, with the total height of the wall depressions and wall projections of adjacent groups defining a total depth of interlock that is in the range of 2 to 6 mm, preferably 3.5 to 4.5 mm. It is thereby particularly preferred also as regards the wall projections and depressions for these to have substantially the same height, i.e. for example, if the total depth of interlock is 4 mm, they each have a height of 2 mm, with the advantages discussed above.
[0013] Aside from the fact that it is arranged in an alternating manner, the design of the bottom profiling and wall profiling is not particularly restricted within the scope of the present invention. However, it has proven to be advantageous for the load-bearing behaviour and producibility if the bottom profiling and/or wall profiling is designed in an undulated or serrated manner. Other forms of bottom profiling and/or wall profiling are also particularly preferred, which will be explained in more detail below with reference to the figures.
[0014] In principle, the bottom projections and bottom depressions could also contribute within the scope of the present invention to the introduction of tensile forces into the respective concrete part. However, it has proven to be advantageous to assign the transmission of tensile forces primarily to the flexible reinforcing loop elements since these have a considerably greater anchorage depth in the respective concrete part and thus enable introduction of tensile forces at a high load-bearing capacity and low deformation. In view hereof, it is provided according to a further development of the present invention that the bottom projections and/or bottom depressions are configured in a trapezoidal manner and comprise flanks that are aligned substantially perpendicular to the bottom. In this manner, the bottom projections and bottom depression optimally contribute to the transmission of shear forces, however leave the transmission of tensile forces (perpendicular to the joint) largely to the flexible reinforcing loop elements.
[0015] The same considerations also apply for the wall projections and wall depressions which, according to a further development of the present invention, have a lower anchoring resistance in concrete in a direction perpendicular to the bottom and thus to the joint than in a direction differing herefrom. In addition to the advantages already discussed above, this design also leads to an improved load-bearing behaviour in the region of the joint cast with mortar when a load is introduced into the concrete. Thus, in the strut-and-tie model discussed above, the component of a compression strut engaging in an inclined manner does not cause, perpendicular to the joint, any or only causes slight additional forces on the side walls of the storage box and thus on the component flanks in the region of the joint, it rather anchors itself primarily on the bottom of the box. At the same time, the shear force components acting parallel to the joint can continue to be effectively anchored at the side walls of the storage box, which benefits force transmission in this direction.
[0016] It has proven to be advantageous within the framework of this concept for the wall projections and wall depressions to have an elongated form which extends substantially perpendicular to the bottom. The narrow side of this elongated form enables the desired low anchoring resistance perpendicular to the bottom, whilst the long side of the elongated form offers a beneficial support surface for the shear force components acting parallel to the joint. It is thereby particularly preferred that the elongated form of the wall projections and wall depressions tapers in the direction extending away from the bottom such that a correspondingly low anchoring resistance results in the direction extending away from the bottom.
[0017] The groups of bottom projections and bottom depressions alternating in the longitudinal direction of the elongated storage box can, within the scope of the present invention, be at different distances to one another (also within an individual connecting device). However, according to a preferred embodiment of the present invention, it is provided that the bottom projections and bottom depressions and the wall projections and wall depressions of adjacent groups are separated by a narrow intermediate surface or directly follow one another. The narrower the respective intermediate surfaces, the better the adjacent groups of projections and depressions supplement one another to form a large total depth of interlock with correspondingly advantageous shear load-bearing behaviour.
[0018] According to a further aim of the present invention, it is provided that the storage box is designed such that two opposite storage boxes of concrete parts that are connected with one another form as small a casting joint as possible, which is able to precisely accommodate the respective flexible reinforcing loop elements in the folded-out state, including a tolerance zone. A small joint volume and thus a reduced need for high-quality and expensive casting mortar is thereby achieved when connecting the concrete parts. This configuration also has a favourable effect on the shear load-bearing behaviour.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 a schematically shows a perspective view of a first embodiment of a connecting device according to the present invention;
[0020] FIG. 1 b schematically shows a perspective view of a storage box of a connecting device of a second embodiment of the present invention;
[0021] FIG. 1 c schematically shows a perspective view of a storage box of a connecting device of further embodiments of the present invention;
[0022] FIG. 2 a schematically shows a sectional view of a storage box of a connecting device according to further embodiments of the present invention;
[0023] FIG. 2 b schematically shows, as an example, different sectional views along the line A-A in FIG. 2 a;
[0024] FIG. 3 schematically shows a perspective view of a part connection using the connecting device according to the invention;
[0025] FIG. 4 schematically shows a partial top view of the part connection as shown in FIG. 3 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] Preferred embodiments of the present invention will be described in detail in the following with reference to the accompanying figures.
[0027] FIG. 1 a schematically shows a perspective view of a connecting device 1 as the first embodiment of the present invention. The connecting device 1 is used for the shear-force-transmitting connection of concrete parts, in particular precast concrete parts, which will be described in more detail below with reference to FIGS. 3 and 4 .
[0028] The connecting device 1 comprises an elongated storage box 2 that is made, for example, of sheet metal and is provided for being concreted into an end face of concrete parts. The storage box 2 has a bottom 5 and two side walls 6 that extend in the longitudinal direction of the bottom. The bottom has through-openings, through which a flexible reinforcing loop element 3 extends such that the loop section comes to rest in the region of the side walls 6 , whilst a clamping sleeve 3 ′ is respectively provided on the opposite side, which connects the free ends of the reinforcing loop element 3 with one another and contributes to improved anchorage in the concrete. The flexible reinforcing loop element can be, for example, a rope formed of wires or wire strands, with the reinforcing loop element, owing to its flexibility, being able to be accommodated in the storage box between the side walls 6 and moved out of the same. FIG. 1 a shows the flexible reinforcing loop elements 3 in the moved-out state.
[0029] The bottom 5 of the storage box 2 has a profiling in the form of bottom projections 7 and bottom depressions 7 ′, which are arranged in an alternating manner at least in sections in the longitudinal direction of the storage box 2 . Thus, as an example, two bottom depressions 7 ′ with a bottom projection 7 arranged therebetween are provided adjacent to each through-opening for a flexible reinforcing loop element 3 in the present embodiment. However, any other number of bottom projections and depressions is also possible within the scope of the present invention, provided that these are arranged in an alternating manner.
[0030] The side walls 6 similarly each have a wall profiling in the form of wall projections 8 and wall depressions 8 ′, which are arranged in an alternating manner in the longitudinal direction of the storage box 2 . Intermediate surfaces 13 that are of different sizes are respectively provided between the bottom projections and depressions and/or between the wall projections and depressions.
[0031] The dimensions of the respective projections and depressions 7 , 7 ′, 8 , 8 ′ can be varied within a large range within the scope of the present invention. In the present embodiment, the bottom projections 7 and the bottom depressions 7 ′ each have a depth (an extension perpendicular to the bottom 5 ) of 3 mm, which results in a total depth of interlock of 6 mm. Similarly, the wall projections 8 and wall depressions 8 ′ each have a height of 2 mm, which results in a total depth of interlock of 4 mm in the region of the side walls 6 .
[0032] Schematically shown in FIG. 1 b is a perspective view of a second embodiment of a storage box 2 in the region between reinforcing loop elements that are not shown herein. This embodiment firstly differs from the one shown in FIG. 1 a in that a larger number of bottom projections 7 and bottom depressions 7 ′ is arranged along the bottom 5 in a continuously alternating manner. Furthermore, the bottom projections 7 and bottom depressions 7 ′ are designed in a trapezoidal manner in the present embodiment and comprise flanks 7 ″ that are aligned substantially perpendicular to the bottom 5 . Even though in FIG. 1 b , intermediate surfaces 13 between the bottom projections 7 and bottom depressions 7 ′, the interlocking with the surrounding concrete can be further increased by making the intermediate surfaces 13 narrower or by omitting them completely such that the bottom projections 7 and bottom depressions 7 ′ directly follow one another.
[0033] The storage box 2 shown in FIG. 1 b furthermore differs from the embodiment shown in FIG. 1 a owing to the design of the wall projections and depressions. Even though only wall projections 8 are shown in FIG. 1 b , the embodiment shown in FIG. 1 b can also comprise alternately arranged wall projections and depressions in accordance with the embodiment shown in FIG. 1 a . Regardless hereof, the wall projections 8 in the embodiment shown in FIG. 1 b are configured such that in a direction substantially perpendicular to the bottom 5 , they have a lower anchoring resistance in concrete than in a direction differing herefrom. To be more precise, the wall projections 8 (and the wall depressions 8 ′ that are not shown here) have an elongated form that extends substantially perpendicular to the bottom and tapers in a wedge-shaped manner in the direction extending away from the bottom 5 . This results in a reduced loading of the flanks of the respective concrete part that abut the side walls 6 .
[0034] FIG. 1 c schematically shows a perspective view of further embodiments of the storage box 2 . FIG. 1 c thereby in particular illustrates different design possibilities for the wall depressions 8 ′, with it also being possible in FIG. 1 c (even though it is not shown) to provide correspondingly alternating wall projections and wall depressions. A number of designs of the wall depressions 8 ′ (and corresponding alternately arranged wall projections 8 ) that are conceivable within the scope of the present invention are schematically shown in the bottom area of FIG. 1 c . All of these designs have an elongated shape that can also be formed, for example, by a group of several round or other shapes. It can furthermore be seen in FIG. 1 c that a tapering design of the shapes is preferred in order to hereby minimise the loading of the flanks of the respective concrete part that abut the side walls 6 . The wall depressions 8 ′ can thereby taper both widthwise and lengthwise.
[0035] The design of the bottom projections 7 and bottom depressions 7 ′ shown in FIG. 1 c substantially corresponds to the design shown in FIG. 1 d , with a round shape instead of a rectangular shape being used herein.
[0036] FIG. 2 a schematically shows a sectional view of another storage box of a connecting device according to the present invention, by means of which different embodiments will be explained as regards the design of the bottom projections and depressions. FIG. 2 b schematically shows, as an example, different sectional views along the line A-A in FIG. 2 a . It must, however, be noted that the sectional views shown in FIG. 2 d are equally applicable for a section made in FIG. 2 a in the region of the wall projections 8 and wall depressions 8 ′.
[0037] As is apparent from FIG. 2 b , the bottom projections 7 and bottom depressions 7 ′ (and/or wall projections 8 and wall depressions 8 ′) can be designed in very different manners within the scope of the present invention, with it being possible on the whole to summarise the design as having an undulated or serrated form. The individual projections 7 and depressions 7 ′ can thereby be separated from one another by means of preferably narrow intermediate surfaces or can also directly follow one another. The bottom projections 7 and bottom depressions 7 ′ can also each be formed by two or more projections or depressions that are grouped together, as is shown, for example, in the third design from the bottom in FIG. 2 b.
[0038] FIG. 2 a furthermore shows two variants for the design of the wall projections 8 and wall depressions 8 ′. Whereas the wall projections 8 and wall depressions 8 ′ shown to the right of FIG. 2 a have a constant height, the wall projections 8 and wall depressions 8 ′ shown to the left of FIG. 2 a are designed in a tapered manner (with a decreasing height), which has the advantages for the load-bearing behaviour that were discussed above.
[0039] The use of the connecting device 1 according to the invention for connecting concrete parts or precast concrete parts 20 is schematically shown in FIG. 3 in a perspective view. The connecting devices 1 are concreted into the end faces 20 ′ of the precast concrete parts 20 in such a manner that the interior defined by the side walls 6 and containing the reinforcing loop elements 3 is facing outwards. The precast concrete parts 20 are then placed together at their end faces 20 ′, thereby forming a casting joint 4 between adjacent connecting devices 1 . The reinforcing loop elements 3 are moved out of the storage boxes 2 in such a manner that they overlap with a corresponding reinforcing loop element 3 of the adjacent storage box 2 .
[0040] A transverse reinforcement in the form of a reinforcing rod 16 is then introduced through the overlapping reinforcing loop elements 3 , whereupon the casting joint 4 can be filled with a suitable casting mortar. A shear-force-transmitting connection (as well as a normal force-transmitting connection) is achieved in this manner between the two precast concrete parts 20 .
[0041] A top view of the part connection as shown in FIG. 3 can be seen in a partial schematic view in FIG. 4 . Even though the precast concrete parts 20 are not shown in FIG. 4 , it can be seen that the respective bottom projections 7 , bottom depressions 7 ′, wall projections 8 and wall depressions 8 ′ enable an effective interlocking both between the connecting device 1 and the concrete of the precast concrete parts as well as between the connecting device 1 and the mortar to be provided in the casting joint 4 .
[0042] It is furthermore apparent from FIG. 4 that the storage box 2 , in particular the width b of the bottom 5 , the height h and the incline a of the side walls 6 , is configured such that the two opposite storage boxes 2 can be pushed closely together so as to form as small a casting joint 4 as possible, which can precisely accommodate the respective flexible reinforcing loop elements ( 3 ) in the folded-out state, including a tolerance zone. For this purpose, the width b of the bottom 5 , the height h and the incline a of the side walls 6 are advantageously adapted in the present embodiment to the progression of the respective reinforcing loop element 3 . | A connecting device ( 1 ) for the shear-force connection of concrete components ( 20 ), in particular prefabricated concrete components, comprises: an elongate protective box ( 2 ) for fitting in an end face ( 20′ ) of the components ( 20 ), which comprises a bottom ( 5 ) and at least two side walls ( 6 ) extending in a longitudinal direction of the bottom; at least one flexible reinforcing loop element ( 3 ) which can be accommodated in the protective box ( 2 ) and can be moved out of the latter; characterized in that the bottom ( 5 ) has a bottom profiling with groups of bottom projections ( 7 ) and bottom depressions ( 7′ ) alternating in the longitudinal direction, wherein each group has at least one bottom projection ( 7 ) or at least one bottom depression ( 7′ ). | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/510,432, filed Jul. 21, 2011.
FIELD OF THE INVENTION
[0002] The present invention relates to medical devices and particularly to a magnetorheological medical brace with controlled stiffness for optimal support and recovery.
DESCRIPTION OF THE RELATED ART
[0003] Any type of trauma or injury to a limb or bone requires a relatively long time to heal. In many cases, the physician usually recommends at least six weeks of recovery time. To ensure proper recovery, the limb or bone is immobilized either by braces, splints or a cast depending on the extent of damage. This stabilizes the bone or limb so as to prevent, in the case of broken bones, undesirable misalignment of the set bone or in the case of sprains or other types of injuries, any movement that may cause further injury or unnecessary pain. While such measures are quite sufficient, the immobilized limb and the surrounding muscles tend to atrophy due to lack of physical movement. It is not unusual for a patient to struggle through a post-recovery regimen of physical exercise or therapy in order to gain the prior musculature and strength in the injured anatomy.
[0004] Another complication to such healing is a matter of comfort and convenience. As the patient endures the period of healing, the recovering area tends to itch, which is usually a positive symptom that recovery is going well. However, for some types of braces, it may be challenging for the patient to reach the agitated area to scratch, which often ends in frustration and irritation. For some, it may even reach unendurable proportions such that the patient is forced to remove the brace, splint or cast, which can jeopardize the healing progress. Moreover, attempts to clean the injured limb can be challenging. Since removal of the brace, splint or cast prior to complete healing is not usually recommended, the patient typically forgoes cleaning of the injured area during the period of recovery. This can lead to unsightly accumulation of dirt and grime or potential infections, especially for patients who had undergone surgery for the injury.
[0005] In order to accelerate healing, re-strengthening of the injured area and increase comfort and convenience for the patient, it would be more effective for a brace, splint or cast to be progressively loosened during the period of recovery such that the patient has some limited movement for exercising the limb as the limb heals, at least for a relatively short period of time. This can be conventionally facilitated by frequent visits to the health care facility for doctor consultation and replacement or adjustment of the medical device. However, frequent visits can be costly in terms of finances and time.
[0006] Sports braces such as those for the joints, e.g., ankles, wrists, knees and elbows, also suffer from similar effectiveness deficiencies. Most sports braces do not have any means of selectively increasing or decreasing the stiffness of the brace. The inherent stiffness of a prescribed sports brace may be sufficient for most, but it could be problematic for those suffering from weak joints or other joint related complications. For example, the stiffness of the brace may dramatically hinder movement, which decreases the benefits of the sports activity and/or the enjoyment thereof. Moreover, as time passes, the user may require more or less support from the brace due to extended movement of the joint or from physical expenditure.
[0007] In light of the above, it would be a benefit in the medical arts to provide an immobilizing device with adjustable stiffness for more effective healing, support, convenience and comfort. Thus, a magnetorheological medical brace having easily adjustable stiffness is needed to solve the aforementioned problems.
SUMMARY OF THE INVENTION
[0008] The magnetorheological (MAR) medical brace includes a flexible outer shell that fits around the anatomical area to be braced and a plurality of adjustable straps for securing the shell onto the anatomical area. The shell encases a MAR pack filled with magnetorheological fluid or gel. A plurality of magnets is attached to or encased in the shell to provide a magnetic field acting on the MAR pack. The interaction of the magnetic field with the MAR pack adjustably increases or decreases the stiffness of the shell depending on the strength of the magnetic field. A control mechanism is provided for selective adjustment of the magnetic field and other functions.
[0009] These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an environmental, perspective view of a magnetorheological medical brace according to the present invention.
[0011] FIG. 2 is a perspective view of the magnetorheological medical brace according to the present invention.
[0012] FIG. 3 is a perspective view of an alternative embodiment of a magnetorheological medical brace according to the present invention.
[0013] FIG. 4 is a perspective view of another alternative embodiment of a magnetorheological medical brace according to the present invention.
[0014] FIG. 5 is a perspective view of a still further alternative embodiment of a magnetorheological medical brace according to the present invention.
[0015] FIG. 6 is a schematic diagram of the controls for a magnetorheological medical brace according to the present invention.
[0016] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The magnetorheological medical brace, a first embodiment of which is generally referred to by the reference number 10 , provides adjustable stiffness and other features for optimum support, convenience and comfort. The phrase “magnetorheological medical brace” will hereinafter be referred to as “MAR medical brace.” In the exemplary embodiment shown in FIGS. 1 and 2 , the MAR medical brace 10 may be a leg brace 12 having an elongate shell or cover 14 adapted to be wrapped around the user's leg L. The shell 14 is substantially semi-cylindrical or semi-frustoconical in shape so that the shell 14 may easily wrap around and conform to the anatomy of leg L. The shell 14 is also relatively stiff or rigid to provide minimum support, as well as to retain the general shape of the shell 14 . However, the shell 14 should also be flexible to allow for some movement without much effort. The shell 14 may be constructed from resilient, polymeric foam with some relative stiffness for minimum rigidity. Other materials such as neoprene, cushioned mats, elastomers, steel, plastics and combinations thereof may also be used as needed for some components of the brace.
[0018] The shell 14 can include a central through hole 18 where a patient's or user's knee joint K may protrude. The hole 18 permits flexing of the knee without encumbrance. A plurality of adjustable attachment connectors, such as straps 16 , may be disposed at spaced intervals along the length of the shell 14 . These straps 16 secure the shell 14 onto a wide range of leg girths. The straps 16 may be secured to the user by hook and loop fasteners, buckles, snap-fit fasteners or any other type of adjustable connectors.
[0019] To facilitate adjustable stiffening of the leg brace 12 , the shell 14 includes a magnetorheological (MAR) cell, tube or pack 20 disposed inside the shell 14 . The MAR pack 20 is preferably a packet or durable balloon filled with magnetorheological material in fluid or gel form. MAR material is a substance that can vary the material yield stress characteristics when exposed to a magnetic field. In other words, the stillness or rigidity of the MAR pack 20 varies, depending on the strength of magnetic forces acting thereon. Thus, whenever the MAR pack 20 experiences some degree of magnetic force or field, the whole leg brace 12 correspondingly stiffens or loosens proportionately to the overall rigidity of the MAR pack 20 . One example of such a MAR material is a combination of carbonyl iron powder and silicone oil. It is to be understood that other MAR materials may also be used for the MAR pack 20 . In the preferred embodiment, the leg brace 12 is of unitary construction formed in a molding process with the MAR pack 20 embedded within the shell 14 . As an alternative, the MAR pack 20 may be removably inserted inside a cavity within the shell 14 .
[0020] The magnetic force or field may be supplied by a plurality of magnet packs, consoles or terminals 30 disposed on one or both sides of the leg brace 12 . Each magnet pack 30 can include a permanent magnet or an electromagnet of a given strength. In a preferred embodiment, the magnet packs 30 are magnetically shielded on the outside to ensure that magnetic forces influence the MAR material, rather than anything else that may be nearby, When using permanent magnets, the physician or the user may selectively change one for another of higher or lower strength to adjust the of stiffness of the MAR medical brace 10 . Similar results may be obtained with an electromagnet by using a control mechanism to adjust the magnetic field strength, an example of which will be described below.
[0021] In the preferred embodiment, the control mechanism 40 may be disposed in one of the magnet packs 30 . As shown schematically in FIG. 6 , the control mechanism 40 includes a processor 42 for controlling the various functions of the control mechanism 40 and is connected to a power source 44 supplying power to the control assembly 40 and the electromagnets in the other magnet packs 30 . In a preferred embodiment, the power source 44 can be a rechargeable and reusable battery, such as lead-acid, nickel cadmium (NiCd), nickel metal hydride (NiMH), lithium ion (Li-ion), and lithium ion polymer (Li-ion polymer). As an alternative, the power may be supplied directly from an AC source. To adjust the strength of the electromagnet, the user can increase or decrease the amount of power being supplied to the MAR pack 20 via the processor 42 to thereby selectively strengthen or weaken the magnetic field. The magnet pack 30 may include an indicator light or display 32 that provides information about the operations of the control mechanism 40 , e.g., ON, OFF and/or remaining power.
[0022] In addition to the basic control of the magnetic field or force, the control mechanism 40 includes other features to help monitor the patient's or user's healing and/or exercise progress. The control mechanism 40 can include a sensor 48 that senses various activities such as the frequency of wear, the intensity of the magnetic field, the frequency of limb movement, etc. This data may be recorded on the data recorder 50 and transmitted wirelessly via the wireless transmitter 46 to a monitoring station, such as a central database in a health care facility or to a personal computer, The recorded and transmitted data helps the physician or user calculate and determine physical activity goals as part of the healing process. Moreover, the data may be used to monitor the user's adherence with the physician's recommendations. For example, if the physician prescribed a strict guideline and duration of wearing the leg brace 12 and the patient fails to comply, as evidenced by prolonged periods of recorded inactivity, the transmitted data will note the lapse and alert the physician. Then the physician may follow up with the patient in a timely manner to determine the cause. As an alternative, the data stored in the data recorder 50 may be retrieved at the end of a given period of time instead of being transmitted by the wireless transmitter 46 , especially for those who live in areas where wireless communication is not available.
[0023] Data transmission and the data itself may be compromised by the magnets used in the MAR medical brace 10 . The magnets may cause magnetic interference, which can reduce the clarity of transmission from the wireless transmitter 46 and potentially damage the data recorded on the data recorder 50 . Since the control mechanism 40 will be subject to magnetic interference from the magnets and/or electromagnets, at least the wireless transmitter 46 and the data recorder 50 are preferably magnetically shielded to overcome potential magnetic interference.
[0024] While the above describes some of the user or patient defined adjustment of the stiffness of the MAR medical brace 10 , the control mechanism 40 includes programming capabilities that may be preset by the physician or possibly the user. For example, the physician may program the MAR medical brace 10 via the processor 42 to gradually decrease the magnetic strength from the magnet packs 30 over the course of the recommended healing or recovery time. This results in the stiffness or rigidity of the MAR medical brace 10 gradually decreasing as the patient heals and grows stronger over time, which eliminates frequent visits with the physician for similar adjustments. Moreover, the wireless transmitter 46 may also function as a receiver in order to receive programs, physician directed adjustments and other commands remotely. In the case of the MAR medical brace 10 being worn for sports or recreational physical activity, the MAR medical brace 10 may be programmed by the user to increase the stiffness over a user-defined period of time so that proper support is maintained as the user becomes physically fatigued from that activity. This relieves constant manual readjustments from the user.
[0025] Referring to FIGS. 3-5 , these drawings show alternative arrangements of the MAR pack for selective reinforcement of the brace. In FIG. 3 , the MAR medical brace 100 in the form of a leg brace includes a plurality of MAR packs 120 embedded in the shell. The MAR packs 120 are shaped as elongate rods for longitudinal reinforcement of the MAR medical brace 100 . The MAR packs 120 are removably inserted into the shell. As an alternative, the elongate MAR packs 120 may be molded with the shell. In FIG. 4 , the MAR medical brace 200 includes a plurality of relative short MAR packs 220 disposed inside the shell. These MAR packs 220 may be placed in a variety of select locations on the MAR medical brace 200 wherever selective stiffening is desired. In FIG. 5 , the MAR medical brace 300 includes a MAR pack 320 that is relatively smaller than the one shown in FIG. 2 . The configuration thereof provides adjustable stiffness in a localized area around the joint. The variety of different MAR pack configurations is subject only to the changing needs of the patient.
[0026] Thus, it can be seen that the MAR medical brace 10 , 100 , 200 , 300 is a highly adjustable brace that promotes optimum healing, convenience and comfort for the user. The MAR packs 20 , 120 , 220 , 320 provide an easy and simple means of adjusting the stiffness and rigidity of the brace for increased comfort and freedom of movement as needed while maintaining the necessary support. The unitary and relatively simple construction also allows the MAR medical brace 10 , 100 , 200 , 300 to be easily and inexpensively manufactured. In addition, the control mechanism 40 provides increased functionality whereby the patient's progress can be easily monitored and tailored to the individual.
[0027] It is to be understood that the MAR medical brace 10 , 100 , 200 , 300 encompasses a variety of alternatives. For example, although the exemplary embodiments above describes the MAR medical brace 10 , 100 , 200 , 300 in terms of a leg brace, it is to be understood that the teachings thereof equally applies to all types of braces. Moreover, the control assembly 40 is not limited to being installed in one of the magnet packs 30 . Instead, the control assembly 40 can be a separate module or remote that can be carried by the user. Furthermore, it is to be understood that the MAR medical brace 10 , 100 , 200 , 300 is not limited to human subjects or patients. The MAR medical brace 10 , 100 , 200 , 300 may also be used on other subjects, such as animals.
[0028] It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims. | The magnetorheological (MAR) medical brace includes a flexible outer shell that fits around the anatomical area to be braced and a plurality of adjustable straps for securing the shell onto the anatomical area. The shell encases a MAR pack filled with magnetorheological fluid or gel. A plurality of magnets is attached to or encased in the shell to provide a magnetic field acting on the MAR pack. The interaction of the magnetic field with the MAR pack adjustably increases or decreases the stiffness of the shell depending on the strength of the magnetic field, A control mechanism is provided for selective adjustment of the magnetic field and other functions. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a conductor detecting device. More specifically, the invention relates to a conductor detecting device which has a simple structure and can reduce erroneous operations.
2. Description of the Related Art
A gearbox accommodating gears is filled with a lubricating oil. When the gears are driven, the gears in mesh produce fine particles or fragments as metal powder or metal shards, which are mingled in the lubricating oil.
A bearing box which accommodates a bearing is also filled with the lubricating oil. When a shaft is driven, fine particles or fragments are produced as metal powder or metal shards from the sliding surfaces of the bearing and the shaft and are mingled in the lubricating oil.
The fine particles or fragments of the gears may be caught by the normal gears or clog a lubricating oil passage in the bear box, causing an adverse effect. And, when the abrasion or damage of the bearing proceeds, the drive of the shaft is adversely affected.
Therefore, detection of the metal powder or metal shards mingled in the lubricating oil enables to judge whether a level of abrasion or damage of the gears or bearing has exceeded a prescribed level.
The gears and bearing are made of metal and are conductors. Accordingly, the gearbox or the bearing box is provided with a metal detecting device for detecting a conductor such as metal powder, metal shards or the like produced due to abrasion or chipping out of the gears or bearing.
FIG. 7 is a diagram showing a structure of a conventional metal detecting device 72 which is disposed in a gearbox.
The metal detecting device 72 is provided with a detecting section 71 . The detecting section 71 is provided with two magnets 70 a , 70 b , which attract metal powder or metal shard M and are disposed with a space between them so to be electrically insulated. In the detection section 71 , electric current Ix, which indicates the detection of the metal powder or metal shard M, flows through a circuit when the magnets are electrically connected by the metal powder or metal shard M which is attracted by the two magnets 70 a , 70 b . The current Ix is directly converted into a warning signal and output or processed as accumulated data, output warning signal or the like by an unshown controller. When the warning signal is output, it can be judged that the abrasion or damage of the gears has exceeded a prescribed level.
When machining to produce the gears, swarf is produced. The swarf often stays on the gear surface even if the gear surface is washed. The swarf adhered to the gear surface is mingled into the lubricating oil.
Furthermore, when the gearbox is being machined, cuttings are produced as metal powder or metal shards. Such cuttings might remain adhered to the inside surface of the gearbox even if the gearbox interior is washed. Therefore, the cuttings adhered to the inside surface of the gearbox are also mingled into the lubricating oil.
There is also a possibility that when the gears are being checked for maintenance, a metal foreign material, which is different from the fine particles or fragments of the gears, is externally mingled into the lubricating oil in the gearbox.
Here, the fine particles or fragments of the gears are attracted by the magnets 70 a , 70 b so to electrically connect the magnets, so that the current Ix flows, and the warning signal is output.
But, the metal detecting device 72 is provided with only one detecting section 71 , so that the current Ix flows and the warning signal is output when the swarf, cuttings or metal foreign material is attracted to the magnets 70 a , 70 b to electrically connect the magnets.
Thus, the metal detecting device 72 had an erroneous operation that a warning signal was output because the current Ix flows when swarf, cuttings or metal foreign material, which is mingled in the same manner as the fine particles or fragments of the gears, is attracted by the magnets 70 a , 70 b to electrically connect the magnets.
For example, Japanese Utility Model Laid-Open Publication No. SHO61-3466 discloses a metal detecting device which is provided with a plurality of detecting sections.
FIG. 8 is a diagram showing the metal detecting device described in Japanese Utility Model Laid-Open Publication No. SHO61-3466.
Metal detecting device 83 of FIG. 8 is configured to have a parallel circuit 82 by disposing a plurality of detecting sections (magnet devices) 81 , each of which has two magnets 80 a , 80 b disposed with a space between them to attract metal (magnetic foreign material). According to this metal detecting device 83 , when metal is attracted to any one of the plural detecting sections 81 , 81 , . . . , the parallel circuit 82 is brought into conduction, and a current indicating the detection of metal flows through the circuit.
The metal detecting device 83 of FIG. 8 is configured to improve its reliability of metal detection by disposing the plural detecting sections 81 . Therefore, according to this conventional metal detecting device 83 , the swarf, cuttings or metal foreign material, which is mingled in the same manner as the fine particles or fragments of the gears, is detected without fail. Thus, the problem of causing an erroneous operation remains unsolved.
For example, the conventional metal detecting device 83 can remedy an erroneous operation by incorporating a logical circuit or performing a judging process by inputting output signals of the plural detecting sections 81 , 81 , . . . , to the controller and, when metal is detected by any one of the plural detecting sections 81 , 81 , . . . , judging that metal is not detected, and when metal is detected by two or more detecting sections 81 , 81 , . . . , judging that metal is detected.
But, addition of the controller to a conventional metal sensor has a disadvantage that the structure become complex and the cost becomes high.
SUMMARY OF THE INVENTION
The present invention has been achieved under the above circumstances, and it is an object of the invention to reduce an erroneous operation by a simple structure.
To achieve the above object, a first aspect of the invention is directed to a conductor detecting device which detects conductors by attracting the conductors to a plurality of magnets, wherein three or more magnets are disposed with spaces between the respective magnets to configure a series circuit; and the conductors are attracted by the three or more magnets so to be electrically connected between the respective magnets to bring the series circuit into conduction, and an electric signal indicating the detection of the conductors is output.
The first aspect of the invention will be described with reference to FIG. 1 .
According to the first aspect of the invention, when two or more conductors M 1 , M 2 , M 3 (three conductors in FIG. 1) are attracted to three or more magnets 1 a , 1 b , 1 c , 1 d (four magnets in FIG. 1 ), the conductors M 1 , M 2 , M 3 are electrically connected between the respective magnets, and a series circuit 3 is brought into conduction to cause a current Is to flow. Thus, an electric signal (voltage Vs (=V) indicating the detection of the conductors M 1 , M 2 , M 3 is output.
According to the first aspect of the invention, when two or more conductors are attracted between the three or ore magnets, the series circuit 3 is brought into conduction for the first time to output the electric signal Vs (=V). Therefore, when only one of the mingled swarf, cuttings or metal foreign material is attracted between the magnets, the electric signal Vs (=V) is not output, and when two or more metals are attracted between three or more magnets, the electric signal Is is output, so that an erroneous operation due to the attraction of one foreign material or the line is not caused.
By disposing the three or more magnets 1 a , 1 b , 1 c , 1 d with a space between them to configure the series circuit 3 , an erroneous operation can be prevented, and addition of a controller to a metal sensor is not needed unlike a conventional art, so that the structure can be made simple, and the cost can be reduced.
A second aspect of the invention relates to the first aspect of the invention, wherein the three or more magnets are arranged around the outer periphery of a rod member.
The second aspect of the invention will be described with reference to FIG. 2 .
According to the second aspect of the invention, the three or more magnets 1 a , 1 b , 1 c , 1 d are arranged around the outer periphery of the rod member 20 .
A third aspect of the invention relates to the first aspect of the invention, wherein the three or more magnets are arranged concentrically.
The third aspect of the invention will be described with reference to FIGS. 4 ( a ), ( b ).
According to the third aspect of the invention, three or more magnets 40 a , 40 b , 40 c are arranged concentrically.
A fourth aspect of the invention relates to the first aspect of the invention, wherein the three or more magnets are arranged in a circumferential direction.
The fourth aspect of the invention will be described with reference to FIG. 5 .
According to the fourth aspect of the invention, three or more magnets 50 a , 50 b , 50 d , 50 d are arranged in a circumferential direction.
A fifth aspect of the invention relates to the first aspect of the invention, wherein the three or more magnets are arranged in parallel.
The fifth aspect of the invention will be described with reference to FIG. 6 .
According to the fifth aspect of the invention, three or more magnets 60 a , 60 b , 60 c are arranged in parallel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an electric circuit diagram showing an embodiment of the present invention;
FIG. 2 is a diagram showing a first layout example of magnets of FIG. 1;
FIG. 3 is a diagram showing a state that a monitoring voltage varies according to a duration elapsed after driving equipment;
FIGS. 4 ( a ) and 4 ( b ) are diagrams showing a second layout example of the magnets of FIG. 1;
FIG. 5 is a diagram showing a third layout example of the magnets of FIG. 1;
FIG. 6 is a diagram showing a fourth layout example of the magnets of FIG. 1;
FIG. 7 is a diagram showing a conventional art; and
FIG. 8 is a diagram showing a conventional art different from FIG. 7 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, embodiments of the conductor detecting device to which the present invention pertains will be described with reference to the accompanying drawings. It is assumed in the following embodiments that the conductor detecting device is a metal detecting device which detects metal mingled in a lubricating oil due to abrasion of metallic gears.
FIG. 1 is an electric circuit diagram showing the metal detecting device of this embodiment.
As shown in FIG. 1, the metal detecting device is broadly comprised of four magnets 1 a , 1 b , 1 c , 1 d , a power supply 4 , an output resistor 5 , electric signal wires 2 a , 2 b and a series circuit 3 .
The series circuit 3 is configured of the four magnets 1 a , 1 b , 1 c , 1 d , the power supply 4 and the output resistor 5 which are connected in series.
The magnets 1 a , 1 b , 1 c , 1 d are separately arranged to detect conductor metals M 1 , M 2 , M 3 . In this embodiment, it is assumed that M 1 is not fine particles or fragments of the gears but swarf (or cuttings, metal foreign materials), and M 2 , M 3 are fine particles or fragments of the gears.
It is assumed that a gap between the magnets 1 a and 1 b , a gap between the magnets 1 b and 1 c and a gap between the magnets 1 c and 1 d are respectively set to such a level that a worn or damaged level of gears has exceeded a prescribed threshold value.
The positive terminal of the power supply 4 is connected to the magnet 1 c through the electric signal wire 2 a . And, the negative terminal of the power supply 4 is connected to the magnet 1 d through the electric signal wire 2 b and the output resistor 5 .
The series circuit 3 is configured by disposing the four magnets 1 a , 1 b , 1 c , 1 d with a space among them as described above. It is assumed that a voltage of the power supply 4 is V, a resistance among all the magnets (which is called as a detection section resistance) is Rs, the output resistor is R, and voltages of both ends of the output resistor 5 (called as monitoring voltage) are Vs.
When the magnets 1 a and 1 b , the magnets 1 b and 1 c and the magnets 1 c and 1 d are electrically connected by the metals M 1 , M 2 and M 3 , the series circuit 3 is brought into conduction, and electric current Is which indicates the detection of the metals M 1 , M 2 , M 3 passes through the series circuit 3 . Thus, the monitoring voltage Vs at either end of the output resistor 5 becomes the voltage Vs (=V) corresponding to the electric current Is as described later. When the monitoring voltage Vs becomes the voltage Vs (=V) corresponding to the current Is, a warning signal is output to the outside.
FIG. 2 shows a layout example of the magnets 1 a , 1 b , 1 c , 1 d.
As shown in FIG. 2, the magnets 1 a , 1 b , 1 c , 1 d are arranged around the outer periphery of a cylindrical rod member 20 . The magnets 1 a , 1 b , 1 c , 1 d are arranged in a longitudinal direction of the rod member 20 . The electric signal wires 2 a , 2 b are disposed in a hollow section of the rod member 20 .
Then, an operation of the metal detecting device shown in FIG. 1 will be described with reference to FIG. 1, FIG. 2 and FIG. 3 . FIG. 3 is a diagram showing a state that the monitoring voltage Vs is varied according to a time elapsed after the gears are driven.
It is assumed that swarf M 1 is suddenly mixed into the lubricating oil at an initial stage when the gears are started to drive. The swarf M 1 is attracted to the magnets 1 a , 1 b within a period of time T 0 to time T 1 , and the magnets 1 a , 1 b are electrically connected by the swarf M 1 . But, the magnets 1 b and 1 c and the magnets 1 c and 1 d are not electrically connected. Therefore, the series circuit 3 is not brought into conduction, and the electric current Is does not flow. The monitoring voltage Vs at this time will be described.
When electrical connection is not established between the magnets 1 b and 1 c and between the magnets 1 c and 1 d , the detecting section resistance Rs is as follows:
Rs=∞ (1)
The monitoring voltage Vs is determined as follows:
Vs= ( R/R+Rs )· V (2)
Therefore, from the above expressions (1) and (2), the monitoring voltage Vs when no electrical connection is established between the magnets 1 b and 1 c and between the magnets 1 c and 1 d is determined as follows:
Vs≈ 0 (3)
When the monitoring voltage Vs is 0, a warning signal is not output to the outside. Specifically, when the swarf M 1 is mingled in the lubricating oil within a period of from drive starting time point T 0 to conducting time point T 1 , error detection resulting in the output of a warning signal can be prevented.
Then, it is assumed that the gears are gradually worn and fine particles M 2 , M 3 are produced and mingled into the lubricating oil. The fine particles M 2 , M 3 are attracted between the magnets 1 b and 1 c and between the magnets 1 c and 1 d at time T 1 , and the electrical connection is established between the magnets 1 b and 1 c and between the magnets 1 c and 1 d by the fine particles M 2 , M 3 . And, the magnets 1 a and 1 b have been electrically connected by the swarf M 1 .
Thus, when the electrical connection is established between the magnets 1 a and 1 b , between the magnets 1 b and 1 c and between the magnets 1 c and 1 d , the series circuit 3 is brought into conduction, and the electric current Is flows it. The monitoring voltage Vs at the time will be considered.
When the electrical connection is established between the magnets 1 a and 1 b , between the magnets 1 b and 1 c and between the magnets 1 c and 1 d , the detecting section resistance Rs is determined as follows:
Rs≈ 0 (4)
The monitoring voltage Vs is determined from the above expression (2) (Vs=(R/R+Rs)·V).
Thus, from the above expression (2) and (4), when the electrical connection is established between the magnets 1 a and 1 b , between the magnets 1 b and 1 c and between the magnets 1 c and 1 d , the monitoring voltage Vs is determined as follows:
Vs≈V (5)
When the monitoring voltage Vs is V, a warning signal is output to the outside. Namely, when the gears are worn and their worn level exceeds a prescribed limit, the warning signal is output.
Similarly, when a gear is chipped and the fragments M 2 , M 3 are attracted between the magnets 1 b and 1 c and between the magnets 1 c and 1 d , the warning signal is also output.
According to this embodiment described above, the series circuit 3 is brought into conduction for the first time when the three metals M 1 , M 2 , M 3 are attracted between the magnets (between the magnets 1 a and 1 b , 1 b and 1 c , and 1 c and 1 d ), the monitoring voltage Vs becomes the power voltage V, and the warning signal is output. Therefore, the attraction of only one of the mingled swarf, cuttings and metal foreign material M 1 between the magnets 1 a and 1 b does not output a warning signal. The warning signal is output only when the two metals M 2 , M 3 are attracted between the magnets 1 b and 1 c and between the magnets 1 c and 1 d . Thus, an erroneous operation due to the attraction of a single foreign material or the like can be prevented.
According to this embodiment, an erroneous operation can be prevented by the series circuit 3 configured by disposing the four magnets 1 a , 1 b , 1 c and 1 d with spaces therebetween. And, a controller is not required to be added to a metal sensor unlike a conventional art, so that the structure can be simplified, and the cost can be reduced.
In this embodiment, it is assumed that the four magnets 1 a , 1 b , 1 c , 1 d are disposed to attract the three magnets M 1 , M 2 , M 3 .
But, the present invention can dispose at least three magnets to attract at least two metals M 1 , M 2 .
For example, when three magnets 1 a , 1 b , 1 c are disposed and two metals M 1 , M 2 are attracted between two magnets (between the magnets 1 a and 1 b and between the magnets 1 b and 1 c ), the series circuit 3 is brought into conduction for the first time, the monitoring voltage Vs becomes the power voltage V, and the warning signal is output. Attraction of at least one of the mingled swarf, cuttings and metal foreign material M 1 between the magnets 1 a and 1 b does not output the warning signal. And, only when the other metal M 2 is attracted between the magnets 1 b and 1 c , the warning signal is output, so that an erroneous operation due to the attraction of a single foreign material or the like can be prevented.
As shown in FIG. 2, the magnets 1 a , 1 b , 1 c , 1 d are arranged around the outer periphery of the cylindrical rod member 20 but they may be arranged in any form. For example, magnets 40 a , 40 b , 40 c may be arranged concentrically as shown in FIGS. 4 ( a ) and 4 ( b ).
FIG. 4 ( a ) is a perspective diagram showing an appearance of a sensor which has the magnets 40 a , 40 b , 40 c arranged concentrically, and FIG. 4 ( b ) is a sectional diagram taken along line A—A of FIG. 4 ( a ).
As shown in FIG. 4 ( a ), the magnets 40 a , 40 b , 40 c are concentrically arranged on a flat surface 41 a of a disc member 41 . The flat surface 41 a of the disc member 40 is immersed in a lubricating oil. An electric signal wire 42 a is connected to the magnet 40 at the center of the concentric circles and an electric signal wire 42 b is connected to the magnet 40 c at the outermost position of the concentric circles. The magnets 40 a , 40 b , 40 c correspond to the magnets 1 a , 1 b , 1 c , 1 d of FIG. 1, and the electric signal wires 42 a , 42 b correspond to the electric signal wires 2 a , 2 b of FIG. 1 . Therefore, when the metals M 1 , M 2 are attracted between the magnets 40 a and 40 b and between the magnets 40 b and 40 c respectively, electric current Is flows through the electric signal wires 42 a , 42 b , the monitoring voltage Vs becomes the power voltage V, and the warning signal is output to the outside.
Magnets 50 a , 50 b , 50 c 50 d may be arranged in a circumferential direction as shown in FIG. 5 .
The magnets 50 a , 50 b , 50 c , 50 d are arranged in the circumferential direction on a flat surface 51 a of a disc member 51 as shown in FIG. 5 . The flat surface 51 a of the disc member 51 is immersed in a lubricating oil. An electric signal wire 52 a is connected to the magnet 50 a , and an electric signal wire 52 b is connected to the magnet 50 c.
The magnets 50 a , 50 b , 50 c , 50 d correspond to the magnets 1 a , 1 b , 1 c , 1 d of FIG. 1, and electric signal wires 52 a , 52 b correspond to the electric signal wires 2 a , 2 b of FIG. 1 . Therefore, when the metals M 1 , M 2 are attracted between the magnets 50 a and 50 b and between the magnets 50 b and 50 c , the electric current Is flows through the electric signal wires 52 a , 52 b , the monitoring voltage Vs become the power voltage V, and the warning signal is output to the outside. And, when metals M 1 , M 2 are attracted between the magnets 50 a and 50 d and between the magnets 50 d and 50 c respectively, the electric current Is flows through the electric signal wires 52 a , 52 b , the monitoring voltage Vs becomes the power voltage V, and the warning signal is output to the outside.
As shown in FIG. 6, magnets 60 a , 60 b , 60 c may be arranged in parallel.
The magnets 60 a , 60 b , 60 c are arranged in parallel on a flat surface 61 a of a disc member 61 as shown in FIG. 6 . The flat surface 61 a of the disc member 61 is immersed in a lubricating oil. An electric signal wire 62 a is connected to the magnet 60 a , and an electric signal wire 62 b is connected to the magnet 60 c.
The magnets 60 a , 60 b , 60 c correspond to the magnets 1 a , 1 b , 1 c , 1 d of FIG. 1, and the electric signal wires 62 a , 62 b correspond to the electric signal wires 2 a , 2 b of FIG. 1 . Therefore, when the metals M 1 and M 2 are attracted between the magnets 60 a and 60 b and between the magnets 60 b and 60 c , the current Is flows through the electric signal wires 62 a , 62 b , the monitoring voltage Vs becomes the power voltage V, and the warning signal is output to the outside.
In the embodiment described above, it was assumed that abrasion of the metallic gears was detected, but the invention can also be applied to a case of detecting the abrasion of metallic bearings.
In this embodiment, it was assumed that metal in a lubricating oil was detected, but the invention can also be applied to the detection of metal in a hydraulic oil of a hydraulic machine. Furthermore, the invention may be applied to the detection of metal mingled into a coolant for cooling an engine other than the detection in oil. And, the invention can also be applied to the detection of a general conductor other than metal. | A device capable of reducing an erroneous operation with a simple configuration in which, when two or more conductors M 1, M 2, M 3 (three of them in FIG. 1 ) are attracted by three or more magnets 1 a, 1 b, 1 c, 1 d (four of them in FIG. 1 ), the conductors M 1, M 2, M 3 are electrically connected between the respective magnets to bring a series circuit 3 into conduction that causes an electric current Is to flow, whereby an electric signal (voltage) Vs(=V) indicating the detection of the conductors M 1, M 2, M 3 is output. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application No. 61/863,401 filed Aug. 7, 2013, which is hereby incorporated by reference herein in its entirety.
BACKGROUND
[0002] Diagnostic tests for various diseases can provide important information for successful treatment. Diagnostic assays are used to detect pathogens, including bacteria and viruses. Many standard diagnostic assays, such as cell cultures and genetic testing with PCR amplification, require sending samples to labs and have long turnaround times of several days or weeks. Many patients, in such cases, do not return to the care provider to receive the results or treatments, and in some cases, the long turn-around can compromise the ability to properly treat the condition.
[0003] While some assays have been automated, many still require significant expertise or training. In many currently available systems the cells to be tested are not adequately processed prior to applying the tests, which can introduce inaccuracies. Alternative systems and methods for diagnostics, could be beneficial for improved patient outcomes, particularly in point of care applications.
SUMMARY
[0004] This application is directed to systems, devices and methods for preparing materials and samples to be used within a point of care device to improve its use in detecting target molecules within a patient's sample. In general, the systems, devices and methods relate to approaches to integrating agents and materials that can be used to prepare samples and react with the samples to detect target molecule. To provide an overall understanding of the systems, devices, and methods described herein, certain illustrative embodiments will be described. It is to be understood that the systems, devices, and methods disclosed herein, while shown for use in diagnostic systems for bacterial diseases such as Chlamydia , may be applied in other applications including, but not limited to, detection of other bacteria, viruses, fungi, prions, plant matter, animal matter, protein, RNA sequences, DNA sequences, as well as cancer screening and genetic testing, including screening for genetic traits and disorders.
[0005] Disclosed herein are systems, devices, and methods for detecting the presence of a pathogen in a biological host, such as in a point of care setting. In certain aspects, materials and methods improve point of care devices by providing pre-loaded, preferably dried, agents for performing one or more of sample lysis and signal enhancement inside the device.
[0006] The systems, devices, and methods described herein may be used for diagnosing a disease in a living organisms such as a human or animal. For example, Chlamydia is a bacterial disease that afflicts humans and is caused by the bacteria Chlamydia trachomatis . A caretaker, such as a nurse or physician, may obtain a sample from a patient desiring to receive a diagnosis for this disorder. For example, the caretaker may use a medical swab to wipe the surface of the vagina, to thereby obtain a biological sample of vaginal fluid and vaginal epithelial cells. If the patient is carrying the Chlamydia trachomatis bacteria, the bacteria would be present in the sample. Additional markers specific to the human genome would also be present. The caretaker or technician then uses the systems, devices, and methods described herein to detect the presence or absence of the bacteria or other pathogen, cell, protein, or gene in the sample.
[0007] In general, the diagnostic systems disclosed herein use probe molecules, preferably protein nucleic acid probes, to detect components within a sample that have matching genetic sequences to the nucleotide sequences of the probe. In that way, bacteria or virus other components of the sample can be detected. Under appropriate conditions, the probe can hybridize to a complementary target marker in the sample to provide an indication of the presence of target marker in the sample. In certain approaches, the sample is a biological sample from a biological host. For example, a sample may be tissue, cells, proteins, fluid, genetic material, bacterial matter or viral matter a plant, animal, cell culture, or other organism or host. The sample may be a whole organism or a subset of its tissues, cells or component parts, and may include cellular or non-cellular biological material. Fluids and tissues may include, but are not limited to, blood, plasma, serum, cerebrospinal fluid, lymph, tears, saliva, blood, mucus, lymphatic fluid, synovial fluid, cerebrospinal fluid, amniotic fluid, amniotic cord blood, urine, vaginal fluid, semen, tears, milk, and tissue sections. The sample may contain nucleic acids, such as deoxyribonucleic acids (DNA), ribonucleic acids (RNA), or copolymers of deoxyribonucleic acids and ribonucleic acids or combinations thereof. In certain approaches, the target marker is a nucleic acid sequence that is known to be unique to the host, pathogen, disease, or trait, and the probe provides a complementary sequence to the sequence of the target marker to allow for detection of the host sequence in the sample. Examples of probes and their use in electrochemical detection assays are disclosed in in further detail in U.S. Pat. Nos. 7,361,470 and 7,741,033, and PCT Application No. PCT/US12/024,015, and U.S. Provisional Application No. 61/700,285, which are hereby incorporated by reference herein in their entireties.
[0008] In certain aspects, systems, devices and methods are provided to perform processing steps, such as purification and extraction and signal amplification, on the sample. Analytes or target molecules for detection, such as nucleic acids, are sequestered inside of cells, bacteria, or viruses. The sample is processed to separate, isolate, or otherwise make accessible, various components, tissues, cells, fractions, and molecules included in the sample. Processing steps may include, but are not limited to, purification, homogenization, lysing, and extraction steps, as well as signal amplification. The processing steps may separate, isolate, or otherwise make accessible a target marker, such as the target marker in or from the sample, and they may also or in addition help amplify the signal detected by the diagnostic system.
[0009] In certain approaches, the target marker is genetic material in the form of DNA or RNA obtained from any naturally occurring prokaryotes such, pathogenic or non-pathogenic bacteria (e.g., Escherichia, Salmonella, Clostridium, Chlamydia , etc.), eukaryotes (e.g., protozoans, parasites, fungi, and yeast), viruses (e.g., Herpes viruses, HIV, influenza virus, Epstein-Barr virus, hepatitis B virus, etc.), plants, insects, and animals, including humans and cells in tissue culture. Target nucleic acids from these sources may, for example, be found in biological samples of a bodily fluid from an animal, including a human. In certain approaches, the sample is obtained from a biological host, such as a human patient, and includes non-human material or organisms, such as bacteria, viruses, other pathogens.
[0010] In one aspect, a biological sample is processed to release or otherwise make accessible, the target molecules or analytes of interest, such as the target marker and control marker. For example, analytes, such as nucleic acids, may normally be sequestered inside of cells, bacteria, or viruses from which they need to be released prior to characterization. For example, mechanical approaches including, but not limited to, sonication, centrifugation, shear forces, heat, and agitation may be used to process a biological sample. Additionally or alternatively, chemical methods including, but not limited to, surfactants, chaotropes, enzymes, or heat may be applied to produce a chemical effect.
[0011] U.S. Application No. 61/700,285 describes diagnostic devices and systems that include an on-board lysis chamber for applying lysis techniques to a biological sample to release target markers from cells within the sample, prior to analyzing the contents of the sample. The contents of that application are hereby incorporated by reference. Lysis techniques disrupt the integrity of a biological compartment such as a cell such that internal components, such as RNA, are exposed to and may enter the external environment. Lysis procedures may cause the formation of permanent or temporary openings in a cell membrane or complete disruption of the cell membrane, to release cell contents into the surrounding solution. For example, a modulated electrical potential can be applied to a sample to release nucleic acids, and in particular, RNA, into the sample solution. Electrical lysis techniques are described in further detail in PCT application No. PCT/US12/28721, the contents of which are hereby incorporated herein by reference. The device and systems of those earlier filed applications can also be modified to include a lysing chamber that uses a chemical lysing agent on board the device. A brief description of these techniques, as applied to the current system, is provided below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing and other objects and advantages will be appreciated more fully from the following further description thereof, with reference to the accompanying drawings. These depicted embodiments are to be understood to as illustrative and not as limiting in any way:
[0013] FIG. 1 depicts a lysis chamber that is configured to be integrated within a point of care device
[0014] FIG. 2 depicts a system for preparing and analyzing a biological sample that can be configured within a point of care device.
[0015] FIG. 3A-FIG . 4 depict embodiments of an on-board lysing chamber structured to lyse biological samples using chemical lysing agents and which can be integrated into the system of FIG. 2 .
[0016] FIG. 5A depicts a cartridge system for receiving, preparing, and analyzing a biological sample.
[0017] FIG. 5B depicts an embodiment of a cartridge for an analytical detection system.
[0018] FIG. 6 depicts an automated testing system to provide ease of processing and analyzing a sample.
[0019] FIG. 7 depicts a hand-held point of care device.
[0020] FIG. 8 depicts in further detail components of this hand-held system illustrated in FIG. 8 .
[0021] FIGS. 9A-9E depict the use and operation of the system or the hand-held device illustrated in FIG. 8 .
[0022] FIG. 10 illustrates an example performed using the system.
DETAILED DESCRIPTION
[0023] FIG. 1 depicts a lysis chamber that is configured to be integrated within a point of care device. The example shown in FIG. 1 is an electrical lysis chamber but as discussed below, can be modified to provide a chemical lysis chamber on-board the device. Chamber 1200 includes a first wall 1202 and a second wall 1204 defining a space 1206 in which a sample is retained. For example, a sample may flow through the space 1206 of the lysis chamber 1200 . Chamber 1200 also includes at least one lysing source (as shown, two lysing sources are included—a first electrode 1208 and second electrode 1210 ). First lysing source ( 1208 ) and second lysing source ( 1210 ) are separated by a spacing 1212 .
[0024] First source 1208 and second source 1210 may be electrical or chemical lysing sources. For example, electrodes may be used that are composed of a conductive material. For example, first source 1208 and second source 1210 may comprise carbon or metal electrodes including, but not limited to, gold, silver, platinum, palladium, copper, nickel, aluminum, ruthenium, and alloys. First source 1208 and second source 1210 may comprise conductive polymers, including, but not limited to polypyrole, iodine-doped transpolyacetylene, poly(dioctyl-bithiophene), polyaniline, metal impregnated polymers and fluoropolymers, carbon impregnated polymers and fluoropolymers, and admixtures thereof. In certain embodiments, first source 1208 and second source 1210 comprise a combination of these materials.
[0025] In certain embodiments, the spacing 1212 separates the first source 1208 and the second electrode 1210 by a range of approximately 1 nm to approximately 2 mm. In certain embodiments, the first electrode 1208 and the second electrode 1210 are inter-digitated electrodes. For example, the first electrode 1208 may have digits 1214 spaced between digits 1216 of the second electrode 1210 . The spacing 1212 can be composed of an insulating material to further localize the applied potential difference to the electrodes. For example, spacing 1212 may comprise silicon dioxide, silicon nitride, nitrogen doped silicon oxide (SiOxNy), paralyene, or other insulating or dielectric materials.
[0026] In the example of FIG. 1 , first source 1208 and second source 1210 are planar electrodes, over which the sample flows. For example, first electrode 1208 , second electrode 1210 , and spacing 1212 are coplanar to form a base within space 1206 of the chamber 1200 . First electrode 1208 and second electrode 1210 may also comprise other configurations, including, but not limited to, arrays, ridges, tubes, and rails. First source 1208 and second source 1210 may be positioned on any portion of chamber 1200 , including, but not limited to sides, bottom surfaces, upper surfaces, and ends. The lysis chamber 1200 , first source 1208 , second source 1210 , and spacing 1212 may have any appropriate length L. Although depicted as having the same length L in FIG. 12 , each component of the chamber 1200 may have a different length. In certain approaches, the length L of the chamber 1200 is between approximately 0.1 mm and 100 mm. For example, the chamber 1200 may have a length L of approximately 50 mm. Similarly, the lysis chamber 1200 , first source 1208 , second source 1210 , and spacing 1212 may have any appropriate width W. Each component of the chamber may have a different width. In certain approaches, the width w of the chamber 1200 is between approximately 0.1 mm and 10 mm. For example, the chamber 1200 may have a width W of 2 mm. The chamber 1200 is depicted as linear or straight, however, in certain approaches, the chamber 1200 includes turns, bends, and other nonlinear structures.
[0027] In certain approaches, lysing pulses (either electrical by electrical pulses or chemical, e.g., by depositing aliquots of chemical lysing agents into the lysing chamber) are applied as the sample continuously flows through chamber 1200 . Lysis pulses may also be applied while the sample is immobile in the chamber, or during agitation of the sample. In embodiments using electrical lysis, the total application time of the pulses is between about 1 second and 1000 seconds. In certain approaches, the pulses are applied for about 2-3 minutes. In certain approaches, the pulses are applied for about 20 seconds or less.
[0028] In certain embodiments, the lysis procedure controllably fragments analyte molecules, such as DNA and RNA. Fragmentation can advantageously reduce the time required to detect or otherwise characterize the released analyte. For example, fragmentation of an analyte molecule may reduce molecular weight and increase speed of diffusion, thereby enhancing molecular collision and reaction rates. In another example, fragmenting a nucleic acid may reduce the degree of secondary structure, thereby enhancing the rate of hybridization to a complementary probe molecule. For example, RNA from a cell lysed by the application of a modulated potential to first electrode 1208 and second electrode 1210 may have an average length of over 2,000 bases immediately upon lysis, but are rapidly cleaved into fragments of reduced length under continued lysing conditions. The average size of such fragments may be up to about between about 20% and about 75% of the size or length of the unfragmented analyte. In certain approaches, the analyte is a RNA. For example, fragmented RNA may have a significant portion of molecules with lengths between approximately 20 and approximately 500 base pairs. In certain approaches, pulses are modulated to simultaneously lyse and fragment the sample and analytes. Additionally or alternatively, a second set of lysing (e.g., electrical or chemical) pulses may be applied and configured to provide specific, controlled fragmentation. For example, a first set of pulses may applied to provide lysis, and a second set of pulses may be applied to provide fragmentation. In certain approaches, the first pulse set for lysis and second pulse set for fragmentation are alternated.
[0029] FIG. 2 depicts a system for preparing and analyzing a biological sample that can be configured within a point of care device. System 1300 includes a receiving chamber 1302 , a first channel, 1304 , a lysis chamber 1306 , a second channel 1308 , an analysis chamber 1310 , and a third channel 1312 . Other processing chambers and channels may also be included. In practice, a user obtains a sample from a biological host and places the sample in receiving chamber 1302 . While in receiving chamber 1302 , the sample may undergo processing, such as filtering to remove undesirable matter, addition of reagents, and removal of gases. The sample is then moved from receiving chamber 1302 through channel 1304 and into lysis chamber 1306 . The sample may be moved by applying external pressure with fluids or gases, for example, with a pump or pressurized gas. In certain embodiments, lysis chamber 1306 is similar to lysis chamber 1200 of FIG. 1 and can be configured with electrical lysing agents such as electrodes. In other embodiments the lysis chamber 1306 is configured as a receptacle that contains one or more lysing chemical agents (as exemplified in FIGS. 3A-10 below). Inside the chamber 1306 , the sample undergoes a lysis procedure, such as an electrical or chemical lysis procedure that lyses the cells in the sample to release the analytes contained therein, including genetic material. The lysis procedure may also cause fragmentation of the analytes released from the cells, such as RNA, which serve as target markers and control marker.
[0030] FIG. 3A-FIG . 4 depict embodiments of an on-board lysing chamber 1306 structured to lyse biological samples using chemical lysing agents and which can be integrated into the system of FIG. 2 . FIG. 3A depicts the chamber 1306 with inlet channel 1304 and outlet channel 1308 , as per FIG. 2 . Inside chamber 1306 is a compartment 102 that contains a chemical lysing agent 100 . Preferably, the lysing agent 100 is in solid, dried form within the compartment 102 . In use, a sample to be tested flows into the chamber 1306 via inlet line 1304 (depicted as arrow A1) and while inside the chamber 1306 flows into the compartment 102 , whereupon the liquid sample inlet mixes with and dissolves the lysing agent 100 . For example, the inlet sample could be a sample buffer containing bacteria or virus that the system is intended to analyze. That buffer, upon contacting the agent 100 within the chamber 102 , then dissolves the agent 100 , changes the pH of the sample which starts a lysing reaction that chemically lyses the cells within the sample. Lysing the cells also exposes the cellular analytes and other components to the lysing agent, which fragments and denatures the components. Included among those components, the genetic material from the cell will fragment when contacting that lysing agent, creating smaller fragments that can more readily bind to probe sequences and are more readily detectable by the diagnostic system contained in the analysis chamber 1310 of FIG. 2 . To that end, lysis exposure time is preferably controlled so that the nucleic acids in the sample are partially fragmented within the sample by the changed pH. The sample, after mixing and at least partial dissolution with the lysing agent, then exits the chamber 1306 via outlet 1308 (as depicted by arrow A2).
[0031] FIG. 4 depicts an alternative embodiment of lysing chamber 1306 . As shown, the chamber 1306 includes two chambers 104 and 106 . Chamber 104 includes compartment 102 a that has lysing agent 101 , for example, a strong base such as NaOH that can lyse cells and denature and fragment genetic and biologic materials in a sample. The lysing reaction that occurs within the compartment 102 a (which is similar to the compartment 102 of FIG. 3A ) is preferably quenched after a certain period of time to stop the lysis of the materials, leaving them in fragmented form so as to prevent ultimate destruction and degradation of the materials beyond their usability in the detection system. Accordingly, second chamber 106 includes a second compartment 102 b that houses a neutralizing agent 103 . For example, this neutralizing agent could be a strong acid that lowers the pH of the sample after it is lysed by the base 101 , to thereby prevent further degradation and denaturation of the genetic material in the sample. In use, the sample flows into the chamber 1306 via inlet line 1304 (see arrow A1) and undergoes lysis and denaturation of its contents within the first chamber 104 , and after which it flows into the second chamber 106 via intermediate line 1305 (arrow A2), whereupon the reaction is quenched. The resulting sample flows out of the chamber 1306 via outlet line 1304 (see arrow A3).
[0032] The lysis chambers of FIGS. 2-4 allow lysis of target sample cells (e.g., virus or bacteria) to be performed on-board the device, preferably by a strong chemical agent (e.g., a base, such as NaOH). A detergent (e.g., SDS, tween, tritonX) is preferably also used in combination with the chemical agent (e.g., the base in the lysing chamber 104 ). In certain implementations, a base is selected as the chemical agent and deposited by drying it to the interior walls of the compartment 102 a inside the lysis chamber 104 . In one mode during lysis, hydroxide from the strong base attacks and breaks down the cells inside compartment 102 a and allows the detergent to create holes in the cellular membrane, thus lysing the bacteria and releasing its genetic material (DNA, RNA) into solution. The released material is then at least partially fragmented by the hydroxide solution. This reaction can then be neutralized in compartment 102 b with the addition of a strong acid to prevent further degradation/denaturation of the genetic material. In certain implementations this lysis process is performed within a single use, hand-held cartridge containing fully active, dried down, long-term room temperature stable reagents.
[0033] In one advantage, the on-board lysing approach also helps stabilize the lysis agent. Many acids are easily dried down and maintain full activity. However, challenges exist in drying down NaOH and maintaining its activity over a period of time. NaOH in its dry form rapidly takes on moisture from its environment and allows dissolved CO 2 to change the base into sodium bicarbonate. This is potentially problematic when drying down liquid NaOH as dissolved CO 2 concentrates in the liquid. The approach described herein provides an elegant solution to that problem, allowing the base to be stabilized for longer term storage or use.
[0034] In the point of case implementation, to prepare the cartridge, the lysing agent(s) are actively dried onto a surface within the interior of the chamber 1306 . In the case of FIG. 4 , active spots of both base and acid are dried on the floor of the separate compartments ( 102 a and 102 b ) of the cartridge. For example, dry powder NaOH and Citric Acid are dissolved in a degassed DiH 2 O, forming two different liquids, thus preventing NaOH exposure to any dissolved CO 2 . These two liquids are then spotted (in μl volumes) in the separate compartments 102 a and 102 b of the cartridge. These spots are rapidly dried down in a vacuum oven, limiting exposure to air and reactive CO 2 . In certain implementations, the cartridge may optimally be quickly packaged into nitrogen purged moisture barrier bags preventing further exposure to moisture and CO 2 . These procedures and conditions allow for the activity of NaOH to remain stable under long-term, room temperature environments.
[0035] Using dry lysis reagents in separate chambers allows the use of a neutral pH sample buffer (e.g., containing a detergent) to flow the sample through the system. The buffer (e.g., phosphate buffered saline solution) carries the sample into the chamber 102 a containing the dry NaOH spot. As the sample buffer containing bacteria flows into the chamber, the buffer dissolves the NaOH spot, raising the pH of the buffer which causes the cells in the sample to lyse. As explained further below, after lysis in chamber 102 a , the sample fluid is then pushed into the compartment 102 b containing the dry acid spot 103 . The acid spot 103 is dissolved and mixed as the solution enters the compartment 102 b via fluid line 1305 (arrow A2). This lowers the pH of the buffer, neutralizing it, and prevents further degradation of the genetic material. The sample, in the neutralized buffer, is then sent to the analysis chamber 1310 (described below) through channel 1308 . Analysis chamber 1310 may include any of analysis chambers 400 , 500 , 600 , 700 , 800 , 900 , 1000 , and 1100 described in U.S. Provisional Application No. 61/700,285.
[0036] The lysing process partially degrades and denatures target genetic material, which helps facilitate direct hybridization detection of nucleic acids of a target when inside the analysis chamber. Smaller fragments of RNA and denatured genomic DNA bind more readily to probe sequences as the secondary structures of these molecules are destroyed. This allows for both increased diffusion of these molecules in solution (increasing hybridization events) and increases accessibility of these to sequences (unfolding) for hybridization. Using separate compartments for base lysis and acid neutralization, the flow from chamber to chamber can be timed (and the on-board fluid pump controlled accordingly) to optimize efficient lysis in concert with adequate degradation/denaturation of genetic material for optimal detection.
[0037] Referring back to FIG. 2 , the analysis chamber 1310 includes one or more sensors, such as pathogen sensors, host sensors, and non-sense sensors. The target markers and control markers can hybridize with probes on the respective sensors. The presence of the target markers and control markers are analyzed at the sensors, for example, with electrocatalytic techniques, as described previously in relation to FIGS. 1-3 . In certain approaches, the sample is then pumped through channel 1312 to additional processing, storage, or waste areas. Further examples of sensor structures and applications are disclosed in U.S. Provisional Application No. 61/700,285, incorporated by reference herein.
[0038] The dimensions, such as lengths, widths, and diameters of the sections of system 1300 can be configured to adjust for different volumes, flow rates, or other parameters. FIG. 2 depicts channel 1308 with diameter d7, analysis chamber 1310 with diameter d8, and channel 1312 with diameter d9. In certain approaches, diameters d7, d8, and d9 are each approximately the same to provide an even flow into and through analysis chamber 1310 . In certain approaches, diameters d7, d8, and d9 have different sizes to accommodate for different flow rates, the addition of reagents, or removal of portions of the sample.
[0039] In certain approaches, the systems, devices, and methods described herein are used for diagnosing a disease in a human. The systems, devices, and methods may be used to detect bacteria, viruses, fungi, prions, plant matter, animal matter, protein, RNA sequences, DNA sequences, cancer, genetic disorders, and genetic traits. For example, the disorder Chlamydia is a bacterial disease caused by the bacteria Chlamydia trachomatis . A caretaker, such as a nurse or physician, may obtain a sample from a patient desiring to receive a diagnosis for this disorder. For example, the caretaker may use a medical swab to wipe a surface of the vagina, to thereby obtain a biological sample of vaginal fluid and vaginal epithelial cells. If the patient is carrying the Chlamydia trachomatis bacteria, the bacteria would be present in the sample. Additionally, markers specific to the human genome would also be present. The caretaker or technician may then use the systems, devices, and methods described herein to detect the presence or absence of the bacteria or other pathogen, cell, protein, or gene.
[0040] The systems, devices, methods, and electrode and lysis zone embodiments described above may be incorporated into a cartridge to prepare a sample for analysis and perform a detection analysis. FIG. 5A depicts a cartridge system for receiving, preparing, and analyzing a biological sample. For example, cartridge system 1600 may be configured to remove a portion of a biological sample from a sample collector or swab, transport the sample to a lysis zone where a lysis and fragmentation procedure are performed, and transport the sample to an analysis chamber for determining the presence of various markers and to determine a disease state of a biological host.
[0041] The system 1600 includes ports, channels, and chambers. System 1600 may transport a sample through the channels and chambers by applying fluid pressure, for example with a pump or pressurized gas or liquids. In certain embodiments, ports 1602 , 1612 , 1626 , 1634 , 1638 , and 1650 may be opened and closed to direct fluid flow. In use, a sample is collected from a patient and applied to the chamber through port 1602 . In certain approaches, the sample is collected into a collection chamber or test tube, which connects to port 1602 . In practice, the sample is a fluid, or fluid is added to the sample to form a sample solution. In certain approaches, additional reagents are added to the sample. The sample solution is directed through channel 1604 , past sample inlet 1606 , and into degassing chamber 1608 by applying fluid pressure to the sample through port 1602 while opening port 1612 and closing ports 1626 , 1634 , 1638 , and 1650 . The sample solution enters and collects in degassing chamber 1608 . Gas or bubbles from the sample solution also collect in the chamber and are expelled through channel 1610 and port 1612 . If bubbles are not removed, they may interfere with processing and analyzing the sample, for example, by blocking flow of the sample solution or preventing the solution from reaching parts of the system, such as a lysis electrode or sensor. In certain embodiments, channel 1610 and port 1612 are elevated higher than degassing chamber 1608 so that the gas rises into channel 1610 as chamber 1608 is filled. In certain approaches, a portion of the sample solution is pumped through channel 1610 and port 1612 to ensure that all gas has been removed.
[0042] After degassing, the sample solution is directed into lysis chamber 1616 by closing ports 1602 , 1634 , 1638 , and 1650 , opening port 1626 , and applying fluid pressure through port 1612 . The sample solution flows through inlet 1606 and into lysis chamber 1616 . In certain approaches, system 1600 includes a filter 1614 . Filter 1614 may be a physical filter, such as a membrane, mesh, or other material to remove materials from the sample solution, such as large pieces of tissue, which could clog the flow of the sample solution through system 1600 . Lysis chamber 1616 may be lysis chamber 1200 or lysis chamber 1306 described previously. When the sample is in lysis chamber 1616 , a lysis procedure, such as an electrical or chemical lysis procedure as described in the embodiments above, may be applied to release analytes into the sample solution. For example, the lysis procedure may lyse cells to release nucleic acids, proteins, or other molecules which may be used as markers for a pathogen, disease, or host. In certain approaches, the sample solution flows continuously through lysis chamber 1616 . Additionally or alternatively, the sample solution may be agitated while in lysis chamber 1616 before, during, or after the lysis procedure. Additionally or alternatively, the sample solution may rest in lysis chamber 1616 before, during, or after the lysis procedure.
[0043] Electrical lysis procedures may produce gases (e.g., oxygen, hydrogen), which form bubbles. Bubbles formed from lysis may interfere with other parts of the system. For example, they may block flow of the sample solution or interfere with hybridization and sensing of the marker at the probe and sensor. Accordingly, the sample solution is directed to a degassing chamber or bubble trap 1622 . The sample solution is directed from lysis chamber 1616 through opening 1618 , through channel 1620 , and into bubble trap 1622 by applying fluid pressure to the sample solution through port 1612 , while keeping port 1626 open and ports 1602 , 1634 , 1638 , and 1650 closed. Similar to degassing chamber 1608 , the sample solution flows into bubble trap 1622 and the gas or bubbles collect and are expelled through channel 1624 and port 1626 . For example, channel 1624 and port 1626 may be higher than bubble trap 1622 so that the gas rises into channel 1624 as bubble trap 1622 is filled. In certain approaches, a portion of the sample solution is pumped through channel 1624 and port 1626 to ensure that all gas has been removed.
[0044] After removing the bubbles, the sample solution is pumped through channel 1628 and into analysis chamber 1642 by applying fluid pressure through port 1626 while opening port 1650 and closing ports 1602 , 1612 , 1634 , and 1638 . Analysis chamber 1642 is similar to previously described analysis chambers, such as chambers 400 , 500 , 600 , 700 , 800 , 900 , 1000 , 1100 , and 1306 . Analysis chamber 1642 includes sensors, such as a pathogen sensor, host sensor, and non-sense sensor as previously described. In certain approaches, the sample solution flows continuously through analysis chamber 1642 . Additionally or alternatively, the sample solution may be agitated while in analysis chamber 1642 to improve hybridization of the markers with the probes on the sensors. In certain approaches, system 1600 includes a fluid delay line 1644 , which provides a holding space for portions of the sample during hybridization and agitation. In certain approaches, the sample solution sits idle while in analysis chamber 1642 as a delay to allow hybridization.
[0045] System 1600 includes a reagent chamber 1630 , which holds electrocatalytic reagents, such as transition metal complexes Ru(NH 3 ) 6 3+ and Fe(CN) 6 3− , for amplifying electrochemical signals that arise when markers in the sample solution bind the probe. This amplification is discussed in further detail in U.S. Pat. Nos. 7,361,470 and 7,741,033, and PCT Application No. PCT/US12/024,015, and U.S. Provisional Application No. 61/700,285, which are hereby incorporated by reference herein in their entireties. In certain approaches, the electrocatalytic reagents are stored in dry form with a separate rehydration buffer. For example, the rehydration buffer may be stored in a foil pouch above rehydration chamber 1630 . The pouch may be broken or otherwise opened to rehydrate the reagents.
[0046] In certain approaches, a rehydration buffer is pumped into rehydration chamber 1630 , where it contacts the dried agents. Adding the buffer may introduce bubbles into chamber 1630 . Gas or bubbles may be removed from rehydration chamber 1630 by applying fluid pressure through port 1638 , while opening port 1634 and closing ports 1602 , 1624 , 1626 , and 1650 so that gas is expelled through channel 1630 and port 1634 . Similarly, fluid pressure may be applied through port 1634 while opening port 1638 . After the sample solution has had sufficient time to allow the markers to hybridize to sensor probes in the analysis chamber, the hydrated and degassed reagent solution is pumped through channel 1640 and into analysis chamber 1642 by applying fluid pressure through port 1638 , while opening port 1650 and closing all other ports. The reagent solution pushes the sample solution out of analysis chamber 1642 , through delay line 1644 , and into waste chamber 1646 leaving behind only those molecules or markers which have hybridized at the probes of the sensors in analysis chamber 1642 . In certain approaches, the sample solution may be removed from the cartridge system 1600 through channel 1648 , or otherwise further processed. The reagent solution fills analysis chamber 1642 . In certain approaches, the reagent solution is mixed with the sample solution before the sample solution is moved into analysis chamber 1642 , or during the flow of the sample solution into analysis chamber 1642 . After the reagent solution has been added, an electrocatalytic analysis procedure to detect the presence or absence of markers is performed, for example any of the analysis procedures described or referenced in U.S. Provisional Application No. 61/700,285 or in U.S. Pat. Nos. 7,361,470 and 7,741,033, and PCT Application No. PCT/US12/024,015, may be applied to the solution to detect the presence or absence of target markers in the sample.
[0047] FIG. 5B depicts an embodiment of a cartridge for an analytical detection system. Cartridge 1700 includes an outer housing 1702 , for retaining a processing and analysis system, such as system 1600 . Cartridge 1700 allows the internal processing and analysis system to integrate with other instrumentation. Cartridge 1700 includes a receptacle 1708 for receiving a sample container 1704 . A sample is received from a patient, for example, with a swab. The swab is then placed into container 1704 . Container 1704 is then positioned within receptacle 1708 . Receptacle 1708 retains the container and allows the sample to be processed in the analysis system. In certain approaches, receptacle 1708 couples container 1704 to port 1602 so that the sample can be directed from container 1704 and processed though system 1600 . Cartridge 1700 may also include additional features, such as ports 1706 , for ease of processing the sample. In certain approaches, ports 1706 correspond to ports of system 1600 , such as ports 1602 , 1612 , 1626 , 1634 , 1638 , and 1650 to open or close to ports or apply pressure for moving the sample through system 1600 .
[0048] Cartridges may use any appropriate formats, materials, and size scales for sample preparation and sample analysis. In certain approaches, cartridges use microfluidic channels and chambers. In certain approaches, the cartridges use macrofluidic channels and chambers. Cartridges may be single layer devices or multilayer devices. Methods of fabrication include, but are not limited to, photolithography, machining, micromachining, molding, and embossing.
[0049] FIG. 6 depicts an automated testing system to provide ease of processing and analyzing a sample. System 1800 may include a cartridge receiver 1802 for receiving a cartridge, such as cartridge 1700 . System 1800 may include other buttons, controls, and indicators. For example, indicator 1804 is a patient ID indicator, which may be typed in manually by a user, or read automatically from cartridge 1700 or cartridge container 1704 . System 1800 may include a “Records” button 1812 to allow a user to access or record relevant patient record information, “Print” button 1814 to print results, “Run Next Assay” button 1818 to start processing an assay, “Selector” button 1818 to select process steps or otherwise control system 1800 , and “Power” button 1822 to turn the system on or off. Other buttons and controls may also be provided to assist in using system 1800 . System 1800 may include process indicators 1810 to provide instructions or to indicate progress of the sample analysis. System 1800 includes a test type indicator 1806 and results indicator 1808 . For example, system 1800 is currently testing for Chlamydia as shown by indicator 1806 , and the test has resulted in a positive result, as shown by indicator 1808 . System 1800 may include other indicators as appropriate, such as time and date indicator 1820 to improve system functionality.
[0050] The foregoing is merely illustrative of the principles of the disclosure, and the systems, devices, and methods can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation. It is to be understood that the systems, devices, and methods disclosed herein, while shown for use in detection systems for bacteria, and specifically, for Chlamydia Trachomatis , may be applied to systems, devices, and methods to be used in other applications including, but not limited to, detection of other bacteria, viruses, fungi, prions, plant matter, animal matter, protein, RNA sequences, DNA sequences, as well as cancer screening and genetic testing, including screening for genetic disorders.
[0051] FIGS. 7-9E illustrate an additional embodiment of a point of care device that integrates on-board dried agents that facilitate sample preparation and lysis as well as catalyzing and enhancing the signal in the analysis chamber. The embodiment shown in those figures includes lysis chamber 1306 , including the two compartments 102 a and 102 b discussed above, but it would be understood that the same point of care device could be configured with a single lysis chamber 1306 with a lysing agent such as a chemical lysing agent having a predetermined concentration sufficient to chemically lyse the cells and partially fragment the cell analytes contained in a patient sample that flows therein. In the depicted embodiment, the dual chamber system of FIG. 4 is used. This system is a variation on the system shown in FIGS. 4-6 , such that analytical data developed or obtained through the use of the system could be programmed and viewed and manipulated and recorded, printed and otherwise controlled by the testing system shown in FIG. 6 .
[0052] FIG. 7 depicts a hand-held point of care device 2000 having a sample inlet chamber 1602 , a lysing chamber 1306 , an analysis chamber with a sensor 1642 that receives fluid from the lysing chamber 1306 after it has been processed through the lysing chamber 1306 and reagent chamber 1630 a and 1630 b . The reagent chambers 1630 a and 1630 b perform a similar function and, in example embodiments, identical function as the reagent chamber 1630 in FIGS. 4-5 , in that they contain catalytic reagents that are dried to the interior surface of the chamber 1630 , and those reagents are hydrolyzed and deployed into the analysis chamber 1642 to amplify the signal from the sensor, as described above in the embodiments of FIGS. 4 and 5 . Applications of electrochemical techniques are described in further detail in U.S. Pat. Nos. 7,361,470 and 7,741,033, and PCT Application No. PCT/US12/024,015, which are hereby incorporated by reference herein in their entireties.
[0053] In particular, in preferred embodiments the reagents included in the reagent chamber 1630 a are a redox pair having a first transition metal complex and a second transition metal complex, which together form an electrocatalytic reporter system (ECAT system) which amplifies the signal from the sensor, indicating a match between the genetic sequence fragments in the lysed sample and the sequences of the PNA probe. Examples of such pairs and amplification are Ru(NH 3 ) 6 3+ and Fe(CN) 6 3− , as further described in U.S. Provisional application No. 61/700,285. These reagents are dried down to the interior walls of the chamber 1630 a . A blister 1631 contains a phosphate buffered salient solution (PBS) that is undiluted from a stock sample (thus the 1×). As will be explained below, after the sample buffer enters the tube 1602 , the blister 1631 is punctured and flows into the chamber 1630 b and thereafter mixes with the components of the ECAT system in 1630 a to form a rehydrated reagent solution. The rehydrated reagent solution later flows into the analysis chamber 1642 , where it meets with the lysate contents from the neutralization chamber 102 b after they are bound and annealed to the sensor, as explained previously and further described below.
[0054] FIG. 8 depicts in further detail components of this hand-held system 2000 , also referred to as a device 2000 . As shown, the neutralization chamber 102 b contains neutralization chemicals 103 (e.g., an acid) and the lysis chemical chamber 102 a contains a lysis agent (e.g., a strong base such as NaOH). As explained above in regard to FIGS. 3A-4 , the neutralization agent and lysis agents are preferably dried to the interior surface of their respective chambers 102 b and 102 a.
[0055] FIGS. 9A-9E depict the use and operation of the system 2000 or the hand-held device 2000 . In a first step as shown in FIG. 9A , the sample is inserted into the sample chamber by the inlet port 1602 and flows by tube 1308 into the lysing compartment 102 a . Inside the lysing compartment 102 a , a strong lysing agent is provided, for example a base such as NaOH. The lysing agent is preferably dried to the interior surface of the compartment 102 a . In certain implementations that agent may be dried within a well or separate receptacle located within the compartment 102 a . In a second step, as shown in FIG. 9B , the blister 1631 is ruptured and releases the PBS into the metering chamber 1630 b and is then pumped into the rehydrolysis chamber 1630 a where the electrode catalytic agents (e.g., the ruthenium and ferric agents identified above) are located and preferably dried to the interior surface of the chamber 1630 a . The chamber 1630 a in this embodiment serves as a multi-use flow chamber to which it can both store the electrode catalytic agents and serve as the locale for rehydrating them, and also function as a receptacle for the receipt of the sample after it has lysed in the lysing chamber 1306 , as described below.
[0056] After the blister 1631 has ruptured, the fluid in the blister flows into the metering chamber 1630 b and is pumped through channel 1635 into the rehydration chamber 1630 a whereupon it mixes with the catalytic agents which are dried to the interior surface of the chamber 1630 a . The dried agents are solubilized in the blister fluid and thereafter they are pumped in reverse direction through channel 1635 back into the metering chamber 1630 b , where they are stored for later use. Alternative designs could be used, where the solubilized electrocatalytic agents (e.g., the ECAT Ru and Fe components) are stored in the rehydration chamber 1630 a and then applied directly to the sensor area 1642 .
[0057] FIG. 9C depicts a next step (which could be applied in reverse order with the step of FIG. 9B ). In this step the sample, which was lysed previously in the lysate formed in the chamber 102 a , is pumped into the neutralization chamber 102 b , where it dissolves a spot of dried neutralizing agent (such as an acid). As that dissolving occurs, the buffer flowing with the sample from chamber 102 a is neutralized in its pH, achieving a pH that is less basic than the pH of the buffer while in chamber 102 a . In preferred implementations the neutralizing agent in chamber 102 b produces a solution of neutral pH such that the solution that exits the chamber 102 b via flow outlet 1038 is of neutral pH and is ready for application to the sensor. That sample leaves the neutralization chamber via flow tube 1308 and is identified in FIG. 9C as sample 1400 .
[0058] As shown in FIG. 9D , the sample 1400 which is preferably neutralized in its pH flows into the hydration chamber 1630 a , which in this embodiment has a multi-purpose use for not only storing the catalytic agents for rehydration, but also then stores the neutralized and lysed sample solution 1400 prior to application to the sensor. This neutralized sample flows through the rehydration chamber 1630 a and it slowly moved across the sensor 1642 where it is subject to the hybridization with the probe located in the sensor 1642 area. The neutralized sample flows down to the waste chamber 1646 after contacting the sensor area 1642 . As depicted in FIG. 9E , after loading the sample onto the sensor 1642 , the rehydrated electrocatalytic agents then flow slowly from the chamber 1630 b through the flow channel 1635 and back to the sensor plate in area 1642 . After the catalytic agents are applied to the sensor then analysis occurs as described above and as explained further in the U.S. Provisional Application No. 61/700,285, the contents of which are incorporated by reference. Applications of electrochemical analysis that can be used are also described in further detail in U.S. Pat. Nos. 7,361,470 and 7,741,033, and PCT Application No. PCT/US12/024,015, which are hereby incorporated by reference herein in their entireties.
[0059] FIG. 10 illustrates an example performed using the system 2000 , including illustrative dried components and their concentrations used in the point of care system 2000 . For example, the ECAT components are dried down separately in chamber 1630 a with Ru(NH 3 ) 6 3+ (30 μl at 0.017 mM) and Fe(CN) 6 3− (30 μl of 7.1 mM). Spots of those components are rehydrated with 213 μl of PBS, which is stored in blister 1631 . The lysis sources (chemical agents) are dried to the chambers 102 a and 102 b . The lysing agent (NaOH in this example) is provided in a 10 μl dried spot on surface 102 a . A sample buffer of 200 μl (0.2 M phosphate buffer at pH 7.2) containing CT bacterial cells is provided through the sample port 1602 . Dissolution of the NaOH spot raises the buffer pH to pH 11 and lyses the bacteria in approximately 3 minutes. Lysis is stopped by neutralizing the buffer to pH 7.2 in chamber 102 b , using Citric Acid. The Citric Acid (10 μl, of 1M) was dry spotted onto the interior surface of the chamber 102 b.
[0060] Variations and modifications will occur to those of skill in the art after reviewing this disclosure. The disclosed features may be implemented, in any combination and subcombination (including multiple dependent combinations and subcombinations), with one or more other features described herein. The various features described or illustrated above, including any components thereof, may be combined or integrated in other systems. Moreover, certain features may be omitted or not implemented.
[0061] Examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the scope of the information disclosed herein. All references cited herein are incorporated by reference in their entirety and made part of this application. | Disclosed herein are systems, devices, and methods for detecting the presence of a pathogen in a biological host, such as in a point of care setting. In certain aspects, materials and methods improve point of care devices by providing pre-loaded, preferably dried, agents for performing one or more of sample lysis and signal enhancement inside the device. | 1 |
SUMMARY OF THE INVENTION
The present invention relates to a device for the pressurized lubrication of an assembly between two mechanical components which can move with respect to each other, one of which is subjected to forces which are cyclically alternating in intensity but not in direction and of variable average intensity, these forces being transmitted to the other via a layer of oil filling an interstice having a defined area of action and located in the interface formed between the two mechanical components, which includes;
means for supplying compressible liquid lubricant at low pressure;
means for generating high pressure in the compressible liquid lubricant comprising a hydraulic pump which includes a piston capable of moving axially in a cylinder between two positions, so as to form a chamber of variable volume, the maximum variation of which is called the swept volume of the pump, the chamber of variable volume being connected, through one-way communication means, to the above-mentioned means for supplying liquid lubricant, and emerging through the one-way communication means into the above-mentioned interstice, and elastic return means acting on the above-mentioned pump piston so as to work against the action of the pressure of the pressurized liquid lubricant;
the above-mentioned means for generating high pressure in the compressible liquid lubricant being actuated directly by the above-mentioned cyclically alternating forces and by the return force of the above-mentioned elastic return means;
the above-mentioned elastic return means being designed to return the piston to its initial rest position when the intensity of the alternating cyclic forces approaches or is close to its minimum cyclic value, an articulation component being interposed between the two mechanical components which can move with respect to each other, the articulation component interacting with the first of the two mechanical components so as to form, between their interacting faces, the above-mentioned interface, and with the second mechanical component so as to form the above-mentioned hydraulic pump.
The invention relates especially to a lubricated device such as an assembly between a connecting rod and a piston, these being articulated to each other, of a fluid-compressing reciprocating machine, such as for example, a connecting rod/piston assembly of a two-stroke internal- or external-combustion reciprocating engine or a positive-displacement compressor. The invention relates especially to those of these assemblies in which the piston possesses, inside an externally cylindrical skirt, a bearing surface which may or may not be partially spherical and is intended to accommodate in an articulated manner the small end, which may or may not be partially spherical, of the connecting rod. Such devices are described in European Patent EP-A-0,280,622 and include:
a telescopic connecting rod, the small end of which has an extremity whose axis is parallel to the main axis of the connecting rod;
a piston sliding reciprocatingly in a cylinder interacting with a cylinder head so as to compress a fluid and having, in its lower part, a recess in which the small end of the connecting rod is housed;
an articulation component interposed between the connecting-rod small end and the piston, which has an external surface which interacts in its upper part, with a minimum functional clearance, with the internal surface of the above-mentioned recess made in the lower part of the piston;
one of the said connecting rod and said articulation component having an extremity made in the form of a cylindrical bush forming a piston and the other having a blind bore in which the above-mentioned extremity in the form of a cylindrical bush slides, with a minimum functional clearance, so as to delimit a first cavity or chamber of variable volume;
means for supplying pressurized liquid lubricant which make the above-mentioned first cavity of variable volume communicate, through a suction valve, with low-pressure supply means made in the connecting-rod shank and, through a delivery valve, with the above-mentioned interstice located in the interface between the internal surface of the above-mentioned recess made in the lower part of the piston and the upper external surface of the above-mentioned articulation component;
elastic return means interposed between the extremity in the form of a cylindrical bush and the upper surface of the blind bore in which this above-mentioned extremity slides;
the combination of the first cavity of variable volume, of the elastic return means and of the suction and delivery valves forming a high-pressure hydraulic pump actuated by the pressure of the compressed fluid which is exerted on the piston.
It is known that the lubrication of the connecting rod/piston articulation is critical in reciprocating engines, and especially engines operating on a two-stroke cycle. This is because, in the latter, the resultant of the forces is always directed in the same direction both at top dead center (TDC) and at bottom dead centre (BDC) so that it is very difficult to lubricate the connecting rod/piston articulation because of the exhaustion of the permanently compressed film of oil.
The above-mentioned European patent provides a solution to the problem, by producing in the device a high-pressure oil pump produced by the above-mentioned articulation component interposed between the connecting-rod small end and the piston, the bore of which forms a pump cylinder in which a pump piston, formed by the cylindrical-bush-shaped small end of the connecting rod, slides, it being possible for the elastic return means to be a spring preferably produced in the form of a metal bar installed in the shank of the connecting rod. This pump operates in delivery mode in the vicinity of TDC when the resultant of the downward forces compresses the spring, and in suction mode by relaxing the spring, the return force of which is greater than the resultant of the downward forces, at least in the vicinity of BDC.
However, this arrangement has several drawbacks. This is because the oil is introduced under pressure into the articulation when the engine piston is in the vicinity of TDC, that is to say, in general, when the forces being exerted on the articulation are a maximum, for example for a two-stroke reciprocating engine or a positive-displacement compressor. The pump must therefore deliver the lubricating oil under a very high pressure and within quite a narrow time window, in the vicinity of TDC. Producing such a device, implementing the sealing and controlling the deformations can therefore prove to be difficult, especially in machines in which high pressures are developed.
The present invention proposes to remedy these drawbacks and to provide a device for the lubrication of a connecting rod/piston articulation and, more generally by extension, of an assembly between two mechanical components which can move with respect to each other and are subjected to cyclically alternating forces, making it possible to ensure, in an efficient manner, lubrication of the interface between the above-mentioned components, by delivering the lubricating liquid at a pressure which is markedly lower than the extreme pressures likely to be reached in the interface, and this being so for a time making it possible to ensure complete supply of the interface, and even in the case of assemblies in which the resultant of the cyclic forces being exerted on the assembly is always oriented in the same direction and in the case where it may reach, cyclically, extremely high maximum values.
As a consequence, and in a general manner, the subject of the invention is an assembly as defined hereinabove and which is characterized in that:
the above-mentioned interstice communicates, preferably permanently, with a cavity of fixed volume forming a reserve of liquid lubricant;
the ratio between the volume of the cavity and the swept volume of the above-mentioned pump being sufficiently high so that, taking into account the compressibility of the compressible liquid lubricant, the above-mentioned pump piston can travel cyclically between its two positions, under only the action of the above-mentioned cyclically alternating forces and of the return force of the above-mentioned elastic return means, at least when the forces reach their maximum average intensity, that is to say the average intensity of the cyclically variable forces during running conditions under which the driving and/or resisting forces to which the components of the assembly are subjected are the highest anticipated for the assembly;
the area of action of the interstice being sufficiently high and the volume of the cavity, with respect to the swept volume of the pump, being sufficiently low so that the pressure generated in the interstice can reach the value enabling the first mechanical component to be moved away from the articulation component during that part of the cycle of variation in the cyclically alternating forces in which the intensity of these cyclic alternating forces is a minimum and at the end of a small number of cycles, preferably one cycle;
the swept volume of the pump being sufficiently high to be able to compensate cyclically for the quantity of liquid lubricant which can leak and escape from the above-mentioned interface via the functional clearances of the assembly, these clearances being sufficiently high to allow hydrodynamic lubrication of the assembly without direct contact between the constituent materials of the latter.
Although it is preferable for the above-mentioned cavity of fixed volume to communicate with the interface permanently, it is understood that it is sufficient for the communication to be established in the vicinity of Bottom Dead Center.
It is preferred that the cavity be filled in a single cycle so as to prevent intermittent lubrication, which is absent during the refilling period.
The assembly according to the invention may advantageously be an assembly articulated between a connecting rod and a piston of a fluid-compressing reciprocating machine as defined hereinabove.
In this embodiment, the volume of the cavity of fixed volume may advantageously be sufficiently high, with respect to the swept volume of the hydraulic pump, so that the pressure in the cavity remains less than the pressure of the said fluid multiplied by the ratio between the cross-section of the piston and the cross-section of the above-mentioned cylindrical bush forming, for example, the extremity of the connecting-rod small end.
The optimum volume of the cavity, taking into account the various dimensional and operational parameters of the assembly between the two components, may be determined, at least approximately, by a simple calculation, one example of which will be given hereinbelow.
In many cases, and especially in the case of devices for the lubrication of the piston/connecting rod articulation of reciprocating engines, especially engines operating on a two-stroke cycle, the volume of the said cavity may advantageously be between 30 and 100 times the swept volume of the pump, which swept volume may be determined in the usual manner knowing the dimensions of the interface, the pressures to which the two surfaces delimiting the interface are subjected and the leakage rate and therefore the desired flow rate of lubricant.
Preferably, the above-mentioned elastic return means are formed by a metal bar, or a bar made of any other suitable elastic material, for example a composite, housed axially in the above-mentioned second metal component and of a sufficiently small section to be completely compressed, so that the above-mentioned articulation component comes into direct contact with the said second metal component when the intensity of the above-mentioned cyclically alternating force is a maximum and directed from the first component to the second, and of a sufficiently large section to be completely relaxed, that is to say in such a way that the above-mentioned chamber of variable volume reaches its maximum value when the intensity of the above-mentioned cyclically alternating force is a minimum, the said bar being long enough so that, between the compressed position and the relaxed position, the material forming the said bar in no circumstance reaches its fatigue limit.
This bar may be produced as a single piece or may consist of two or more telescopic components arranged inside one another so as to obtain a large total longitudinal travel.
The fixed cavity according to the invention may be arranged in the articulation component or even in the above-mentioned first mechanical component, for example a piston, in which case the outlet for the liquid lubricant to the interstice is located in the communication between the delivery valve and the cavity. The cavity may also be made partially in the articulation component and the said first mechanical component.
The means which provide the unidirectionality of the lubricant flows may be conventional self-actuated seated valves, for example ball valves.
However, in an improvement of the invention which makes it possible to avoid the problems owing to inertia, to the low permeability and to the operating delay in this kind of valve, a suction valve may advantageously be used whose opening and closing are controlled directly by the movement of the hydraulic pump. For example, this suction valve of the hydraulic pump may be formed by a ring, preferably with no cut, housed in a circular groove made in the upper part and at the periphery of a cylindrical bush forming the upper extremity of the above-mentioned second mechanical component forming the piston of the pump and interacting with the above-mentioned articulation component by sliding axially in a blind cylindrical bore made in the articulation component, the external diameter of the ring, before mounting, being slightly greater than the internal diameter of the above-mentioned blind cylindrical bore so that this ring, when mounted, is lightly clamped in the bore, the internal diameter of this ring being substantially greater than the internal diameter of the groove and its height being substantially less than that of the groove so as to be able to move up and down in the groove, and the upper face of this ring being provided with radial passages enabling the compressible liquid lubricant to flow out from the above-mentioned chamber of variable volume to the above-mentioned means for supplying compressible liquid lubricant at low pressures when the ring is bearing on the upper face of the groove, the extra height of the circular groove with respect to the height of the ring being less than the compression stroke of the elastic return means.
When the above-mentioned first mechanical component forms the body of a cylindrical piston sliding in a cylinder of a fluid-compressing machine, the above-mentioned second mechanical component forms a connecting rod, the upper extremity of which may advantageously be cylindrical in order to interact with the above-mentioned articulation component which interacts with the above-mentioned first mechanical component in order to form the interface to be lubricated, sliding axially in a blind cylindrical bore made in the lower part of the articulation component, so as to form a pump chamber of variable volume.
In this case, the above-mentioned articulation component may be formed by a cylindrical gudgeon pin which is perpendicular to the main axis of the connecting rod and which interacts partially, with a minimum functional clearance, with a bore whose axis is perpendicular to the axis of the piston and which is of a diameter equal, to within the functional clearance, to that of the cylindrical gudgeon pin.
The above-mentioned articulation component may also be formed by a component whose upper external surface is partially spherical (by partially spherical is meant a surface allowing articulation of the ball-joint type) and whose axis lies on the axis of the connecting rod, and which includes, in its lower part, a blind cylindrical bore interacting with the above-mentioned cylindrical extremity of the connecting rod in order to form the above-mentioned chamber of variable volume. The above-mentioned first mechanical component, forming the piston body, includes a lower recess, the internal surface of which is also partially spherical and the center of which lies on the main axis of the connecting rod, so as to interact partially, with a minimum functional clearance, with the external surface of the above-mentioned articulation component.
BRIEF DESCRIPTION OF THE DRAWINGS
Other advantages and characteristics of the invention will appear on reading the following description, given by way of non-limiting example, and with reference to the appended drawing in which;
FIG. 1 represents a diagrammatic sectional view of a device according to the invention with an articulation of the ball-joint type;
FIG. 2 represents a diagrammatic sectional view of a device according to the invention with an articulation of the pivot-pin type;
FIG. 3 represents a view of a device according to FIG. 1 with an improved inlet-valve means;
FIG. 4 represents a view of a device similar to FIG. 1 with a telescopic metal bar acting as an elastic return means;
FIG. 5 represents a variant of this device in the case of a ball having a small bearing surface;
FIG. 6 represents such a device for a two-stroke engine with sealing means between the first component and the articulation component;
FIG. 7 represents a diagrammatic view on a larger scale, intended to explain the operating principle of the invention;
FIG. 8 represents a view similar to FIG. 7, with an improved inlet-valve system; and FIG. 8A represents an enlarged view of the circled portion of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is first of all made to FIG. 1
Shown in this figure is an assembly in accordance with the invention, comprising a first movable mechanical component (1), namely a two-stroke diesel engine piston, which moves in a cylinder (not shown) of the engine under the effect of the engine gases, and a second movable mechanical component, namely a connecting rod (2), the big end of which is mounted on an engine crank (not shown) and the small end (3) of which is articulated under the piston (1).
The articulation is effected by means of an articulation component (4) of generally spherical shape, the upper spherical surface of which bears against a thin shell (5), also of partially spherical shape, accommodated in the bottom of a cylindrical internal recess having a spherical upper end face made in the piston (1).
Housed between the shell (5) and the bottom of this recess is a material (6) which is capable of creeping and plays an adaptation role, for example described in Patent EP-A-0,280,622, it being impossible for this material to pass out of the volume thus created between the piston and the shell (5) because of the sealing produced between the shell and the piston in the cylindrical region of the recess and in the corresponding cylindrical region of the shell.
The lower face of the shell (5) forms one of the faces of the interface to be lubricated while the polar part of the upper surface of the articulation component (4) forms the other face of the interface.
As a consequence, the two faces delimit an interstice capable of being filled with lubricating oil and bordered, at its periphery, by a substantially annular region in which the surfaces of the component (4) and of the shell (5) may come into contact in the absence of oil.
The articulation component or ball (4) is kept in place inside the cavity in the piston (1) by virtue of a retaining ring (7) pushed up in the direction of the upper part of the piston by an elastic element (8) and it is therefore understood that a certain axial travel is possible between the component (4) and the shell (5) of the piston along the vertical axis of revolution of the piston.
As already described in European Patent EP-A-0,280,622, the articulation component (4) has, on the lower side, a blind bore (9) centered on the longitudinal axis of the piston and forming a pump chamber.
The upper extremity of the small end (3) of the connecting rod (2) can slide in this bore (9), said upper extremity being machined so as to have a cylindrical shape in order to form a pump piston capable of sliding in the bore (9) in order to determine with it the chamber (10), of variable volume, of the pump.
Arranged in the shank of the small end (3) is an elastic return means produced in the form of a metal bar (11) which is housed with a functional clearance in an axial hole in the connecting rod and the length of which, in the free state, is greater than the depth of the hole so as to extend into the chamber (10) and come into contact with the bottom of the bore (9) made in the ball (4).
This bar thus forms an elastic element capable of being compressed when the downward-oriented resultant of the forces, which is applied by the piston on the articulation component (4), is high, especially in the vicinity of TDC, and of being uncompressed when this force resultant becomes low, especially in the vicinity of BDC.
The pump thus produced is supplied with liquid lubricant by means of a channel which is made longitudinally in the connecting rod (2) and the lower extremity (not shown) of which receives the influx of low-pressure oil or lubricant, as is well known.
The duct (12) emerges in the chamber (10) via a suction check valve (13) which allows low-pressure oil to pass upwards only when the pressure in the chamber (10) becomes less than the low pressure of the supply.
Delivery by the pump is provided by a duct (14) emerging into the chamber (10), provided with a delivery check valve (15), and emerging into the interstice (16) between the ball (4) and the shell (5).
In accordance with the invention, a cavity (17) of fixed volume is provided in the delivery passage and, in this case, this cavity (17) is made in the ball (4) itself, the ball possibly consisting, for example, of two parts joined together in order to produce the cavity.
Reference is now made to FIG. 2 which is distinguished from FIG. 1 essentially by the fact that the articulation component (4a) consists of a cylindrical gudgeon pin pivoting in a corresponding transverse cylindrical bearing surface of the piston (1), being held in place therein by axially retaining circlips so that the interface between the first and second movable mechanical components, that is to say the piston (1) and the connecting rod (2), is formed by the internal surface of the transverse bearing surface (18) of the piston and the external surface of the gudgeon pin or pivot (4a).
A blind bore (9) is made, as previously, in the articulation component (4a) in order to accommodate the connecting-rod small end with its bar and its suction inlet provided with the one-way suction valve.
The delivery duct (14a) provided with its one-way delivery valve (15) emerges into the interface via a widening region (19) which is constantly in communication via ducts (20) with two constant-volume cavities (17a).
It is understood that, in this embodiment, the cavities (17a) are not directly located in the delivery duct but that they simply communicate directly with the duct, downstream of the valve (15), at the interface.
In accordance with the invention, the constant-volume cavity (17 or 17a), arranged between the delivery valve (15) of the pump and the oil outlet into the interface of the articulation, forms an oil accumulator or reservoir, the volume of which is sufficiently greater than the working swept volume of the pump in order to limit the pressure increase, but sufficiently low to increase the pressure sufficiently to allow the accumulated oil to flow out into the articulation when the force being exerted on the piston (1) drops down again, and especially, for example, when the piston comes back down to BDC, by more than the half-stroke, this being so in a limited number of cycles, preferably in a single cycle.
Referring to FIGS. 7 and 8, it may be seen that the above-mentioned cavity, referenced (17b), of fixed volume Vi, may be made in the above-mentioned first mechanical component (1), for example a piston of a two- or four-stroke engine, this cavity communicating directly with the volume of the interstice (16a, 19a) via a duct (14b) in communication with the delivery duct (14) made in the articulation component (4b).
It may further be seen in FIG. 7 that the pump piston may be formed by a cylindrical-bush-shaped extremity of the articulation component, the blind bore then being made in the extremity of the second movable component, for example a connecting rod.
The operation is as follows:
Under steady running conditions, a film of oil is present between the two surfaces of the interface, that is to say between the shell (5) and the component (4).
At TDC, the resultant of the forces transmitted downwards by the piston to the connecting rod by means of the interface and of the movable component (4) is a maximum and the lubrication of the interface takes place by exhaustion of the film of oil.
In this position, the bar (11) is completely compressed and the chamber (10) at its minimum volume.
As the piston/connecting rod assembly descends, the force transmitted downwards progressively decreases and, for example, a little after the half-stroke of the piston, it becomes sufficiently low to allow the bar (11) to start to relax and, consequently, to allow the chamber (10) to increase in volume.
A decrease in pressure in the chamber (10) then allows the suction valve (13) to open and oil to flow in via the low-pressure duct (12) towards the chamber, it thus being possible for this influx of oil into the chamber to be spread over a significant portion of the machine's cycle on either side of BDC.
When the piston comes back up after having reached BDC, the resultant of the forces, which is owing to the compression of the fluid in the chamber of the engine cylinder, increases until the bar starts to be compressed, so that the suction valve (13) is applied against its seat and so that the pressure of the oil in the chamber (10) increases, causing the delivery valve (15) to open and causing the oil to pass into the accumulator-forming cavity (17) when the pressure in the chamber (10) increases sufficiently to exceed the pressure in the cavity (17), the leakage rate of the oil out of the cavity (17) becoming progressively smaller, because of the increase in the pressure on the film of oil in the interstice owing to the increase in the force applied by the piston downwards on the articulation component (4) and because of the progressive exhaustion of the oil.
Moreover, when during the descent of the piston the force transmitted via the piston to the ball (4) becomes sufficiently low, the pressure of the oil compressed in the cavity (17) exerted on the two faces of the interstice is sufficiently high to increase the separation between the components (1) and (4), allowing a quantity of oil to leave the cavity (17), to rejoin the interstice between the ball (4) and the shell (5), and to spread out from this interstice in order to renew the film of oil in the clearance between the two movable components.
In this case, the magnitude of the effective section of the interstice, of the volume of the cavity with respect to the swept volume of the pump, enabling the pressure in the chamber (10) to be controlled, and of the swept volume of the pump actuated cyclically in order to renew at each cycle the film of oil between the two components (1) and (4) with a sufficient flow rate and therefore a thickness of oil enabling this film to be never totally exhausted during the rest of the cycle, is clearly known.
It is clear that the volume of the cavity (17) and the swept volume of the pump may be adjusted so that this outflow of oil occurs during a major period of the cycle on either side of BDC.
It is clear that, under steady running conditions, the average delivery rate of the pump is equal to the flow rate of the flow of oil through the functional clearance.
This flow rate increases directly in proportion to the clearance so that natural adjustment of the clearance occurs.
The delivery rate of the pump (and therefore its swept volume) will therefore have to be chosen so as to be sufficient for the articulation to remain under conditions of hydrodynamic lubrication, without direct contact between the surfaces of the interface.
At start-up, the oil pressure in the accumulator (17) is zero. This pressure will increase as soon as the pump is able to send its quantity of oil to the accumulator (17).
It is desirable for this pressure to increase sufficiently quickly so that a quantity of oil can escape, close to BDC, in order to penetrate into the interstice of the interface of the articulation and to ensure lubrication.
As the example described hereinbelow shows, this condition may be reached in a very small number of cycles, preferably in just one.
Example: MT 135 engine of 135 mm bore
For this example, reference may also be made to FIG. 7.
Cross-section of the piston: 143 cm 2
Total mass of the piston (piston body and the articulation): 10 kg
Mass of the piston proper (without its articulation): 7 kg
Maximum combustion pressure: 300 bar
Minimum pressure in the cylinder at BDC: 18 bar
Speed of rotation: 1800 rpm
Stroke: 170 mm
Length of the connecting rod: 284 mm
Upward acceleration at TDC: 400 g at 1800 rpm
Downward acceleration at BDC: -216 g at 1800 rpm
Downward force at TDC: 300×143-400×10=38.9 ton, i.e. 381,220 N.
Downward force at BDC: 18×143+216×10=4.7 ton, i.e. 46,060 N.
Preload of the metal bar: 10 ton, i.e. 98,000 N.
Stiffness of the metal bar: Kb=10 ton/mm, i.e. 98,000 N.
Working swept volume of the pump: 400 mm 3 per cycle
Cross-section of the pump piston: Sp=8 cm 2
Working stroke of the pump: 0.50 mm
Effective section of the interface of the articulation: 10 cm 2
Fixed volume of the oil cavity: 12 cm 3 i.e. 30 times the swept volume of the pump!.
Coefficient of compressibility of the oil Kh=15,000 bar
Operation of the Articulation
When the piston of the engine approaches its Top Dead Center (TDC), the downwardly directed forces clearly dominate and as a result completely compress the metal bar until it comes against its stop: ##EQU1##
At each stroke of the pump, the pressure rise in the reservoir will in fact, to a first approximation, be:
P=15,000×(V/V)=15,000×400/12,000=500bar.
The complete swept volume of the pump will therefore be stored in the oil cavity at a pressure of at least 500 bar (assuming that the pressure is zero in the reservoir at the start of the compression cycle).
This pressure exerted on the effective section (10 cm 2 ) of the interstice will exert an upward force of 500×10/1000=5 ton, i.e. 49,000 N., which will tend to move the piston body away from the articulation component, but this force is counteracted by the downward force, applied on the piston body, which is (143×300-7×400)/1000=40.1 ton, i.e. 392,980 N.
On the other hand, when the piston of the engine approaches Bottom Dead Center (BDC), the upward forces clearly dominate: ##EQU2##
This means that towards mid-stroke of the piston downwards, the metal bar will become uncompressed and that the pump will fill up again with one swept volume via the clearance of the delivery and suction valves.
Moreover, the pressure existing in the interstice (500 bar) will exert an upwardly directed force of 5 ton, i.e. 49,000 N, on the effective section of the interstice (10 cm 2 ) while the forces exerted downwards on the piston body are now only: ##EQU3##
The clearance between the two components will therefore open and discharge the oil reservoir, lubricating the articulation as the oil passes.
It may be understood that if the volume of the cavity (17) is much smaller, for example comparable to the swept volume of the pump, a very high pressure will be obtained in the interface in the vicinity of TDC whereas the hydraulic pump will only operate at a low delivery rate.
In contrast, if the volume of the reservoir is too high, the pressure in the cavity of fixed volume will be insufficient and a large number of cycles of the engine piston will be necessary in order to pressurize the volume, with the risk of operating without lubrication during this filling time, this situation occurring in a periodic manner.
In contrast, by virtue of the invention, by a judicious choice, on the one hand, of the swept volume of the pump and, on the other hand, of the fixed volume of the cavity, the person skilled in the art may determine the dimensions for the assembly so as to make the oil penetrate into the interface at a relatively moderate high pressure, for example less, by more than half, than the pressure which would have to be developed if the pump were to deliver directly into the interface without a cavity, and for a sufficiently long period of time to ensure that the oil flows out correctly into the interface.
Reference will now be made to FIGS. 3, 8 and 8A.
On account of the fact that a single suction valve, such as (13), has problems associated, for example, with its inertia, it may be advantageous, instead, to use a suction valve means whose opening and closing are controlled directly by the movement of the hydraulic pump.
As may be seen in FIGS. 3 and 8, the suction duct (12) of the connecting rod emerges directly into a peripheral groove (20) in communication with the small clearance between the cylindrical wall of the piston formed by the connecting-rod small end (3) and the concentric cylindrical wall of the bore (9).
A usual sealing ring (21) is provided under the groove (20).
In contrast, above the groove (20), a circular groove (22) is made in which a ring (23) may travel longitudinally and radially, the initial diameter of this ring (23) being slightly greater than the diameter of the bore (9) so that, when fitted, this ring is lightly clamped against the cylindrical surface of the bore.
As may be seen in the figure, the internal diameter of this ring is substantially greater than the internal diameter of the groove (22) and its height is substantially less than that of the groove, the difference between the height of the groove and the height of the ring being less than the compression stroke of the elastic return means formed by the bar (11).
Furthermore, the upper surface, that is to say the surface facing the chamber (10), of the ring (23) is provided with a plurality of small radial grooves enabling the oil to flow out.
In suction mode, that is to say when the volume of the chamber (10) is increasing, the relaxation of the bar pushes the articulation component (4) back, which drives the ring upwards because of its clamping, but the oil can pass radially through the upper face of the ring and penetrate into the chamber (10), lubricating, as it passes, the interstice between the small end (3) and the bore (9).
In delivery mode, the ring (23) is pushed back downwards and its lower face, bearing on the lower face of the groove, prevents the oil from returning.
Reference is now made to FIG. 4.
When it is desired to develop a large swept volume of the pump for liquid lubricant, while still using a metal bar for the elastic return, the problem arises of the elastic resistance of the material of which the bar is composed.
The elastic compressibility stroke of the bar may be substantially increased, without increasing its longitudinal extent, by producing a telescopic bar consisting of a first bar part (24) capable of travelling longitudinally in a cylindrical recess internal to the connecting-rod small end (3), having a peripheral shoulder (25) resting on the upper extremity of the connecting rod, while the bottom (26) is some distance from the bottom of the cylindrical recess in the connecting rod, this first bar part (24) accommodating, with a functional clearance, a second cylindrical bar part (26) which, at rest, and when it is applied against the bottom of the first bar part (24), extends beyond the shoulder (25) in order to come into contact with the articulation component (4) and thus determine the position of larger volume of the chamber (10).
Referring to FIG. 5, an arrangement of the articulation according to the invention may be seen in which the rubbing surface of the spherical articulation component (4) and of the shell (5a) is small so as to avoid mechanical losses and a pinching effect of the equatorial part of the ball by the cylindrical bearing surface of the shell.
This is effected by the use of a shell (5a) of diameter less than the diameter of the sphere and housed in a cylindrical extension of low height and having a spherical bottom made in the piston (1).
Reference is now made to FIG. 6.
In order to establish circulation of lubricating oil in the piston using the low-pressure oil inlet (12) in the connecting rod, it is possible to produce an oil branch-off, as shown in FIG. 5.
However, it is necessary to prevent the oil from immediately dropping back downwards and, for this purpose, it is necessary to provide sealing at the ring (7) and the elastic means (8), as shown in FIG. 5.
In order to eliminate the rubbing forces which result therefrom, it is possible to omit the ring (7) and the elastic element (8) because, at least in a two-stroke diesel-type engine, the resultant of the forces exerted by the piston (1) is always directed downwards, that is to say towards the connecting-rod small end.
In this case, it is enough to arrange, at the lower extremity of the skirt of the piston, a retaining means (27) which, normally, is not in contact with the articulation component (4), and to provide, in the equatorial plane of the ball (4), a single seal (28) housed, for example, in a groove in the internal surface of the skirt of the piston (1).
The branch-off (29) of the conduit (12) thus terminates in a volume (20) internal to the piston sealed at its lower part, from which volume it is possible to establish the circulation of oil in the piston. | A device including a first moving part such as a piston (1) and a second moving part such as a connecting rod (2) with a coupling part (4) therebetween. A low-pressure compressible liquid lubricant feed system delivers a liquid into a chamber (10) with a variable volume between the second part and the coupling part, to form a pump supplying the joint interstice (16) to be lubricated, by a one-way connection (13, 15) and a resilient return member (11), wherein the interstice communicates with a cavity (17) with a fixed volume used as a liquid lubricant source. The volume, in relation to the pump displacement, enables a degree of deflection of the pump piston (3) while achieving a sufficiently high pressure and compensating for leakage. | 5 |
TECHNICAL FIELD
[0001] The present invention relates to the field of obtaining a combustible gas chosen from methane, methanol, dimethyl ether (DME) or diesel by heterogeneous catalysis.
[0002] The production processes according to the invention comprise a step of high-temperature water electrolysis (HTE for “High Temperature Electrolysis” or HTSE for “High Temperature Steam Electrolysis”) or a step known as co-electrolysis of water and carbon dioxide CO 2 at high temperature and a step of manufacturing combustible gas by catalytic reaction.
[0003] The invention relates more particularly to a novel design of reactor whose pressure chamber houses both a high-temperature electrolysis reactor, or electrolyzer (HTE), with a stack of elemental electrolysis cells to produce either hydrogen or a “syngas” (an H 2 +CO mixture) from steam H 2 O and carbon dioxide CO 2 and at least one catalyst arranged downstream of the electrolyzer outlet to convert via heterogeneous catalysis into desired combustible gas the syngas obtained previously either directly from the electrolysis reactor or indirectly by mixing the hydrogen produced with carbon dioxide CO 2 injected into the chamber.
PRIOR ART
[0004] Among the bulk energy storage solutions already envisaged, hydraulic storage is already widespread. The remaining capacities for this type of storage risk being rapidly saturated. In addition, hydraulic systems require particular geographic and geological conditions and may as a result prove to be rather expensive. Given the future storage problems, hydraulic storage can therefore be only a partial solution.
[0005] An alternative storage solution has also been envisaged: this is compressed air storage (CAES, the abbreviation for “Compressed Air Energy Storage”). According to this technology, it is envisaged to store compressed air produced with electricity in underground cavities. These cavities also demand specific geographical characteristics, such as saline cavities. However, the yield of this storage solution is unsatisfactory.
[0006] Finally, hydrogen is announced as an energy vector that is susceptible to be capable of bulk storage of electricity in certain configurations: mention may be made here of the project already carried out in Corsica under the acronym MYRTE (acronym for Mission hYdrogène Renouvelable pour l'Intègration au Rèseau Electrique) at the Applicant's initiative.
[0007] However, all these bulk energy storage solutions require the development of extensive infrastructures (hydraulic-specific sites, underground cavities, hydrogen storage systems). This is why, more recently, bulk energy storage by conversion of renewable electricity into chemical energy via the production of synthetic fuel has made significant inroads, representing a storage alternative of great potential. Mention may be made here of patent application US 2009/0289227 which mentions technical conversion solutions.
[0008] Moreover, reducing the emissions of carbon dioxide CO 2 resulting from the use of fossil energies, upgrading as much as possible the CO 2 derived from the use of these energies rather than storing it for an indefinite period, using on demand electricity derived from “decarbonized” energy sources, especially during periods of over production, converting this electricity into a storable product that may make it possible to produce electricity on demand during periods of production deficit without having to resort to the use of high-carbon energies are all objectives to be achieved for the sake of global efficiency.
[0009] The manufacture of a combustible syngas from a mixture of steam and carbon dioxide CO 2 , by means of decarbonized electricity, satisfies these objectives.
[0010] The electrolysis of steam H 2 O to produce hydrogen H 2 and/or the co-electrolysis of H 2 O+CO 2 at high temperature in a solid oxide electrolyzer is one of the possibilities. The reactions for the electrolysis of steam (I) and for the co-electrolysis of H 2 O+CO 2 (II) take place according to the following equations:
[0000] Electrolysis of water: H 2 O→H2+1/2O2 (I)
[0000] Co-electrolysis: CO2+H 2 O→CO+H2+O2 (II).
[0011] Thus, the electrolysis of steam H 2 O allows a “direct” manufacture of combustible gas by heterogeneous catalysis by injection of a mixture of hydrogen H 2 produced via electrolysis (I) and of carbon dioxide CO 2 into a catalyzer.
[0012] The co-electrolysis of H 2 O+CO 2 allows an “indirect” manufacture of combustible gas from the syngas (H 2 +CO) produced via co-electrolysis (II).
[0013] The combustible gas thus manufactured may be a hydrocarbon and especially methane, the main component of natural gas.
[0014] The production of synthetic natural gas gives the possibility of immediately using all the existing infrastructures developed for this energy: transportation and distribution networks, storage capacities, electricity production systems, etc. In addition, it also emerges that the carbon balance for this production may be zero, or even negative, since the electricity used would be of decarbonized origin and the CO 2 would be derived from systems using fossil energies that would have been taken up beforehand.
[0015] To perform the electrolysis of water (I), it is advantageous to perform it at high temperature typically between 600 and 950° C., since part of the energy required for the reaction may be provided by heat, which is less expensive than electricity, and the activation of the reaction is more efficient at high temperature and does not require a catalyst. To perform high-temperature electrolysis, it is known practice to use an electrolyzer of SOEC type (acronym for “Solid Oxide Electrolyte Cell”), consisting of a stack of elementary units each comprising a solid oxide electrolysis cell, consisting of three superposed anode/electrolyte/cathode layers, and of interconnecting plates made of metal alloys also known as bipolar plates, or interconnectors. The function of interconnectors is to ensure both the passage of the electrical current and the circulation of gases in the region of each cell (steam injected, hydrogen and oxygen extracted in an HTE electrolyzer; air and hydrogen injected and water extracted in an SOFC cell) and to separate the anode and cathode compartments which are the compartments for gas circulation on the anode side and the cathode side, respectively, of the cells. To perform high-temperature steam electrolysis HTE, steam H 2 O is injected into the cathode compartment. Under the effect of the current applied to the cell, the dissociation of the water molecules in vapor form takes place at the interface between the hydrogen electrode (cathode) and the electrolyte: this dissociation produces hydrogen gas H 2 and oxygen ions. The dihydrogen is collected and removed at the hydrogen compartment outlet. The oxygen ions O 2− migrate toward the electrolyte and recombine as dioxygen at the interface between the electrolyte and the oxygen electrode (anode).
[0016] The co-electrolysis of steam and CO 2 (II) potentially offers the same energy and economic advantages as those described above for the electrolysis of steam (reaction (I)) without the drawback of having to perform intermediate condensation between the electrolysis of water and the electrolysis of CO 2 . Its advantage lies in the possibility of performing the co-electrolysis reaction (II) in the same reactor by maintaining the reactor in a temperature range in the region of 800° C. Specifically, at this temperature, the voltages required for the reduction of CO 2 to CO and of H 2 O to H 2 are virtually identical. By way of example, the abandon voltages, i.e. the electrical voltages obtained without electrical current but solely by means of the different gases on either side of a cell, for a mixture of 90% oxidized species and 10% reduced species at 800° C., are, respectively, equal to 0.852 V for the H 2 O, H 2 /O 2 couples and 0.844 V for the CO 2 , CO/O 2 couples.
[0017] Furthermore, high-temperature co-electrolysis has the same energy advantage as steam electrolysis between 750 and 900° C. relative to low-temperature water electrolysis. Specifically, the energy required for the dissociation of H 2 O molecules is reduced by the vaporization energy. Moreover, the kinetics of the electrolysis reactions of H 2 O and CO 2 are highly thermally activated and follow an Arrhenius law with activation energies of the order of 120 kj/mol. Consequently, the efficiency of the reactions improves greatly when the temperature is increased. The higher electrochemical activity at high temperature also makes it possible to dispense with expensive catalyst, such as platinum required at lower temperatures. In addition, the production of syngas in the cathode compartment of the co-electrolysis reactor is accompanied by a production of oxygen in the anode compartment, which may be upgraded thereafter, for example for the oxycombustion of natural gas.
[0018] That being said, although the high-temperature co-electrolysis (II) as envisaged offers the abovementioned advantages, namely the investment of a single electrolysis reactor, thermal coupling between the various reactions, it has the drawback of not making it possible to obtain a variable H 2 /CO ratio in the mixed gas at the reactor outlet. In other words, when co-electrolysis is performed, a desired outlet H 2 /CO ratio imposes a given inlet H 2 O/CO 2 ratio. Specifically, operation close to the thermo-neutral operating point sets the voltage to be applied to the electrolyzer. Thus, for a desired outlet H 2 /CO ratio with a degree of water conversion close to 100%, the inlet CO 2 and H 2 O rates and compositions must necessarily be determined.
[0019] However, each syngas intended to produce a combustible gas requires a given H 2 /CO ratio as a function of the targeted fuel. Similarly, the direct manufacture of combustible gas requires a given CO 2 /H 2 ratio as a function of the targeted fuel.
[0020] Table 1 below thus illustrates the ratios required as a function of processes for synthesizing different fuels:
[0000]
TABLE 1
COMBUSTIBLE
CO 2 /H 2
SYNTHETIC
PRODUCT
H 2 /CO RATIO
RATIO
PROCESS
OBTAINED
REQUIRED
REQUIRED
Synthesis of
Natural gas
1/3
1/4
methane
Synthesis of
Methanol
1/2
1/3
methanol
Synthesis of
DME
1/1
1/2
dimethyl ether
(DME)
Fischer-Tropsch
Diesel
1/2
1/3
synthesis
[0021] The Applicant proposed in the patent application filed on Dec. 17, 2012 under the number FR 12 62174 a novel co-electrolysis process and reactor for obtaining at the outlet a variable H 2 /CO ratio and thus a syngas whose composition is adapted to produce the desired combustible gas.
[0022] Moreover, the operating point adopted for an electrolysis or co-electrolysis reactor also sets the thermal conditions in the electrolysis reactor. Specifically, for electrolyses performed at high temperature, the energy ΔH required for dissociation of the inlet molecule (H 2 O or CO 2 ) may be provided in electrical and/or heat form. The thermal energy provided Q is then defined as a function of the voltage U at the terminals of each electrolysis cell by the relationship:
[0000]
Q
=
I
2
F
Δ
H
-
U
·
I
,
[0023] in which U is the electrical voltage, I is the electrical current and F is the Faraday constant. Thus, three operating regimes are defined, corresponding to three different thermal modes for the stack of electrolysis cells:
the “autothermal” mode in which the imposed voltage Uimp is equal to ΔH/2F. The heat consumed by the dissociation reaction is completely compensated for by the various electrical resistances of the electrolyzer (irreversibilities). The electrolysis reactor (electrolyzer) does not require any particular thermal management, while at the same time remaining temperature-stable; the “endothermic” mode in which the imposed voltage Uimp is less than ΔH/2F. The electrolyzer consumes more heat than the electrical losses therein. This required heat must thus be supplied thereto by another means, otherwise its temperature will irremediably drop; the “exothermic” mode in which the imposed voltage Uimp is greater than ΔH/2F. The electrolysis then consumes less heat than the electrical losses via the Joule effect. This evolution of heat in the electrolyzer must then be evacuated by another means, otherwise its temperature will prohibitively increase.
[0027] The endothermic mode requires less consumption of electricity: there is thus little production and heat needs to be supplied to the electrolysis reactor. The advantage of this endothermic mode lies in the availability of an inexpensive source of heat. Everything then depends on the nature and on the temperature of this heat source.
[0028] In contrast, the exothermic mode requires a larger consumption of electricity: there is thus substantial production, but the electrolysis reactor must be cooled, which may be very expensive. The advantage of this exothermic mode then depends greatly on the cost of the electricity and the use of the excess heat.
[0029] Thus, the heat management of an electrolysis or co-electrolysis reactor is an important factor to be taken into consideration.
[0030] In addition, the transportation, storage and use of hydrogen require its pressurization. It is already known practice, instead of compressing the hydrogen produced, which entails a considerable cost, to perform the electrolysis of water directly using steam under pressure, the water then being compressed into liquid form beforehand, which is much less expensive.
[0031] Various processes for obtaining a combustible gas by heterogeneous catalysis either directly using a mixture of H 2 and carbon dioxide CO 2 , or indirectly using a syngas (H 2 +CO) have already been studied.
[0032] In particular, the hydrogenation of CO 2 to methane is an industrial process that has been studied at each energy shock, either to produce synthetic methane from pure CO 2 and H 2 , or in coal gasification plants with more complicated gases and conditions (Fischer-Tropsch process).
[0033] For the methanation process, two routes are possible and have been more or less extensively studied in the prior art.
[0034] The first route is the direct route, with a single reaction according to the following equation:
[0000] CO 2 +4H 2 →CH 4 +2H 2 O
[0035] The second route is the indirect route, with a two-step reaction according to the following equations:
[0000] CO 2 +H 2 →CO+H 2 O
[0000] CO+3H 2 →CH 4 +H 2 O.
[0036] As demonstrated by the authors of the publication [1] (see especially FIGS. 3 and 4 ), methanation reactions are favored at high pressure and at low temperature according to the Le Chatelier law. Specifically, the thermodynamic calculations indicated in [1] indicate a theoretical conversion of 100% of CO 2 into CH 4 at less than 150° C. as opposed to 83% at 400° C. However, it is also indicated that a minimum temperature and an optimum gas rate is to be adjusted in order to ensure sufficient kinetics. The optimum temperature at which the methanation should be performed is thus a compromise between the desired degree of conversion of CO 2 and the desired reaction kinetics.
[0037] The catalysts used for methanation are generally based on nickel supported on a zirconium oxide (ZrO 2 ) or based on nickel (Ni) supported on an aluminum oxide (Al 2 O 3 ). Publication [1] highlighted the high catalytic activity for a catalyst based on nickel (Ni) supported on mixed oxides of cerium (Ce) and zirconium of formula Ce0.72Zr0.28O2. Similarly, publication [2] showed, for a methanation at a pressure of 30 bar, the excellent catalytic activity of a bimetallic catalyst based on nickel (Ni) and iron (Fe) supported on an aluminum oxide (Al 2 O 3 ) of formula Ni—Fe/γ-Al 2 O 3 .
[0038] Several types of reactors have already been envisaged for performing methanation.
[0039] Mention may be made first of fixed-bed reactors in which the solid catalyst is integrated in the form of grains or pellets. The drawback of reactors of this type is that the heat management is difficult to perform for exothermic reactions such as methanation.
[0040] Mention may also be made of reactors with structured channels such as multitubular reactors, monolithic reactors and plate reactors, in which the solid catalyst is generally deposited in the form of a coating in the reactive channels. These reactors are well suited to a methanation reaction which requires good heat management. They are generally more expensive.
[0041] Finally, reactors of entrained or fluidized-bed type in which the catalyst to be fluidized is in powder form. These reactors are well suited to reactions with very large volumes of reagents. Furthermore, fluidization of the catalyst allows very good thermal homogenization of the mixture of reagents in the reactor and thus better heat control.
[0042] Irrespective of the direct or indirect route, the solid catalyst, or the type of reactor used to date, methanation remains an expensive process with a yield that is still to be improved, especially due to the subsequent compression of the methane obtained, which is necessary for its storage and/or transportation and due to the separate production of the hydrogen required, in particular by HTE electrolysis or high-temperature co-electrolysis. The effective coupling to date, between methanation and electrolysis, is far from having been achieved.
[0043] Patent application FR2931168 describes an electrolyzer of proton type, i.e. with circulation of protons H+ in the electrolyte, into which water H 2 O is introduced at the anode and CO 2 or CO is introduced at the cathode, in order to form methane or other fuels. The type of materials used is far from being tried and tested. In addition, the efficiency of methanation in such a proton electrolyzer is far from having been proven.
[0044] There is thus a need to improve the methanation process especially in order to lower its investment and production cost and in order to improve its yield.
[0045] More generally, there is a need to improve the known synthetic processes for obtaining a combustible gas chosen from methane, methanol and DME, especially in order to lower their investment and production costs and in order to improve their yields.
[0046] The aim of the invention is to at least partly satisfy these needs.
DESCRIPTION OF THE INVENTION
[0047] To do this, according to one of its aspects, and in a first alternative, the invention relates to a process for obtaining a combustible gas chosen from methane, methanol, dimethyl ether (DME) and diesel by heterogeneous catalysis, comprising the following steps:
[0048] a/ a step of high-temperature electrolysis of steam H 2 O performed in an electrolysis reactor housed in a leaktight chamber maintained at a given pressure, in which step a/ each cathode of the reactor is fed with steam at the given pressure;
[0049] b/ a step of catalytic conversion performed in at least one reaction zone placed at a distance from and radially to the electrolysis reactor in the same chamber under pressure and containing at least one solid conversion catalyst, step b/ being performed using hydrogen H 2 produced during the electrolysis step a/ and carbon dioxide CO 2 injected into the space between the electrolysis reactor and the radial reaction zone;
[0050] c/ a step of recovery of the combustible gas produced and of the steam not converted in step a/ and produced in step b/, in the space between said radial reaction zone and the wall(s) delimiting the chamber.
[0051] According to a second alternative, the invention relates to a process for obtaining a combustible gas chosen from methane, methanol, dimethyl ether (DME) and diesel by heterogeneous catalysis, comprising the following steps:
a′/ a step of high-temperature co-electrolysis of steam H 2 O and carbon dioxide CO 2 performed in a co-electrolysis reactor housed in a leaktight chamber maintained at a given pressure; in which step a′/ each cathode of the reactor is fed with steam H 2 O and carbon dioxide CO 2 at the given pressure;
[0053] b′/ a step of catalytic conversion being performed in at least one reaction zone placed at a distance from and radially to the co-electrolysis reactor in the same chamber under pressure and containing at least one solid conversion catalyst, step b′/ being performed using hydrogen H 2 and carbon monoxide CO produced during the co-electrolysis step a′/;
[0054] c′/ a step of recovering the combustible gas produced and the steam not converted in step a′/ and produced in step b′/, in the space between said radial reaction zone and the wall(s) delimiting the chamber.
[0055] It is pointed out that, in the context of the invention, the high temperatures of the electrolysis step a) or co-electrolysis step a′) should not be confused with the low temperatures at which an electrolysis of alkaline type is performed.
[0056] In the context of the invention, the term “leaktight chamber under a given pressure” should be understood here to mean a chamber that is leaktight with respect to the external atmosphere and whose interior is maintained at a pressure above atmospheric pressure.
[0057] According to an advantageous embodiment, the reaction zone consists of a porous partition containing the solid conversion catalyst.
[0058] The term “porous partition” means an assembly formed from one or more walls whose overall porosity allows the passage of the gases present in the chamber, i.e. the methane formed in the partition and steam. The assembly may thus consist of at least two grilles, grates, metal sheets or two substrates made of highly porous ceramic and of which the space separating them contains at least one solid conversion catalyst according to step b/ or b′/.
[0059] The term “reaction zone placed at a distance from” and “porous partition placed at a distance from” means an arrangement with a sufficient space between the zone (porous partition and the electrolysis/co-electrolysis reactor so that the temperature of the gases reaches a range of values suitable for performing step b) or b′). Typically, the optimum temperature for performing the methanation step b) or b′) is about 400° C., and a sufficient space is thus provided for the H 2 produced with the CO 2 injected or the H 2 +CO mixture produced in the region of 800 to 850° C. to reach a temperature of about 400° C. when it enters the reaction zone (porous partition).
[0060] Step b/ or b′/ is preferably performed with the radial reaction zone closed on itself, being arranged concentrically around the electrolysis or co-electrolysis reactor, respectively.
[0061] Step a/ or a′/ is advantageously performed at temperatures of between 600° C. and 1000° C., preferably between 650° C. and 850° C.; more preferably between 700 and 800° C.
[0062] Step b/ or b′/ is advantageously performed at temperatures of between 250° C. and 500° C., preferably between 300° C. and 400° C.
[0063] Step a/ or a′/ is preferably performed at pressures of between 0 and 100 bar, preferably between 4 and 80 bar, i.e. a range between the pressure in a medium-pressure distribution network (4 bar) and that in natural gas pipelines (80 bar).
[0064] According to an advantageous embodiment, the walls delimiting the chamber are cooled to a temperature below the saturation temperature of water at the given pressure of the chamber, such that step c/ or c′/ consists of a separation of the combustible gas from the water condensed in the chamber, followed by a recovery of the combustible gas separated out and of the condensed water by gravity on the bottom of the chamber.
[0065] The process advantageously constitutes a methanation process. In such a process, advantageously, the given pressure of the chamber and the operating pressure of the electrolysis or co-electrolysis reactor is equal to about 30 bar, the temperature for performing step a/ or a′/ being maintained equal to about 800° C., the temperature in the radial reaction zone being maintained equal to about 400° C., the temperature of the walls delimiting the chamber being maintained below 230° C.
[0066] In another of its aspects, the invention also relates to a reactor for obtaining a combustible gas chosen from methane, methanol, dimethyl ether (DME) and diesel by heterogeneous catalysis, comprising:
a leaktight chamber capable of being placed under a given pressure; a reactor either for the high-temperature electrolysis of steam or for the high-temperature co-electrolysis of steam and carbon dioxide, comprising a stack of elemental electrolysis cells of SOEC type each formed from a cathode, an anode and an electrolyte intercalated between the cathode and the anode, and a plurality of electrical and fluid interconnectors each arranged between two adjacent elemental cells with one of its faces in electrical contact with the anode of one of the two elemental cells and the other of its faces in electrical contact with the cathode of the other of the two elemental cells, the electrolysis or co-electrolysis reactor being housed in the chamber and the outlet of the cathodes emerging inside the chamber; at least one porous partition placed at a distance from and radially to the electrolysis or co-electrolysis reactor in the chamber and containing at least one solid catalyst for converting syngas (H 2 +CO or H 2 +CO 2 ) into combustible gas; at least one tube for feeding steam under pressure and, where appropriate, carbon dioxide to the cathodes of the electrolysis or co-electrolysis reactor, where appropriate, at least one tube for injecting carbon dioxide of the space between the electrolysis reactor and the porous partition; at least one tube for recovering combustible gas and/or steam, where appropriate, at least one tube for recovering water condensed on the walls delimiting the chamber, each tube passing through a wall delimiting the chamber.
[0074] It is pointed out here that the electrical and fluid interconnection devices, also known as interconnectors or interconnection plates, are devices which provide connection in series from an electrical point of view of each electrolysis cell in the stack of HTE reactors and in parallel from a fluid point of view, thus combining the production of each of the cells. The interconnectors thus ensure the functions of bringing and collecting current and delimit gas circulation (distribution and/or collection) compartments.
[0075] The electrolysis cells are advantageously of cathode-supported type. In the context of the invention, the term “cathode-supported cell” means herein the definition already given in the field of high-temperature water electrolysis HTE and referred to by the acronym CSC, i.e. a cell in which the electrolyte and the oxygen electrode (anode) are arranged on the hydrogen or carbon monoxide electrode (cathode), which is thicker and thus serves as a support.
[0076] According to an advantageous embodiment, the porous partition is closed on itself, being arranged concentrically around the electrolysis or co-electrolysis reactor. The porous partition preferably consists of two porous metal walls, the space separating them being at least partially filled with a conversion catalyst in the form of powder or granulates. The two metal walls each preferably consist of a sheet perforated with a plurality of holes regularly spaced both along the height and along the length of the partition.
[0077] The solid conversion catalyst is preferably based on nickel (Ni) supported on a zirconium oxide (ZrO 2 ), or based on nickel (Ni) supported on an aluminum oxide (Al 2 O 3 ), or bimetallic based on nickel (Ni) and iron (Fe) supported on an aluminum oxide (Al 2 O 3 ), preferably Ni—Fe/γ-Al 2 O 3 , or based on nickel (Ni) supported on mixed oxides of cerium (Ce) and zirconium, preferably Ce 0.72 Zr 0.28 O 2 .
[0078] The porous partition advantageously comprises, in the solid catalyst, part of the cooling circuit capable of cooling the catalytic reaction between the hydrogen and carbon monoxide produced upstream in the co-electrolysis reactor or between the hydrogen produced upstream in the electrolysis reactor and carbon dioxide injected into the space between the porous partition and the electrolysis reactor.
[0079] The feed tube is preferably partly wound on itself close to the electrolysis or co-electrolysis reactor to heat the steam under pressure and, where appropriate, the carbon dioxide before feeding the cathodes.
[0080] According to an advantageous embodiment variant, the reactor comprises a tube for recovering the hydrogen and, where appropriate, the carbon monoxide produced at the cathodes, the recovery tube being wound on itself forming a circle and being pierced with a plurality of holes regularly distributed along the circle to homogeneously diffuse the hydrogen and, where appropriate, the carbon monoxide into the space between the electrolysis or co-electrolysis reactor and the porous partition arranged concentrically.
[0081] The carbon dioxide injection tube is preferably wound on itself forming a circle and pierced with a plurality of holes regularly distributed along the circle to homogeneously diffuse the carbon dioxide into the space between the electrolysis or co-electrolysis reactor and the porous partition arranged concentrically.
[0082] According to an advantageous embodiment variant, the leaktight chamber comprises a side envelope, a lid and a base assembled with the envelope in a leaktight manner, and a first support for supporting both the electrolysis or co-electrolysis reactor and the porous partition so as to place them at a distance from the base and from the lid of the chamber.
[0083] Preferably, the reactor comprises a second support, fixed onto the first support, for supporting only the electrolysis or co-electrolysis reactor so as to place it facing the central portion of the porous partition, preferably halfway up the porous partition.
[0084] According to an advantageous embodiment variant, the side envelope comprises part of a cooling circuit at a temperature below the saturation temperature of water at the given pressure.
[0085] The base of the leaktight chamber advantageously constitutes a basin for recovering the water condensed on the lid and/or the side envelope and/or the base.
[0086] According to another of its aspects, the invention relates to a system comprising:
a reactor that has just been described; a heat exchanger forming a steam generator for vaporizing liquid water at the given pressure, the exchanger being placed outside the chamber.
[0089] In such a system, part of the secondary circuit of the exchanger advantageously comprises the tube for recovering the water condensed in the base.
[0090] The cooling circuit of the porous partition advantageously constitutes the primary circuit of the heat exchanger for vaporizing the liquid water at the given pressure.
[0091] In yet another of its aspects, the invention relates to a process for operating a co-electrolysis reactor described above, according to which steam is fed and distributed to the cathode of one of the two adjacent elemental cells and carbon dioxide is fed and distributed to the cathode of the other of the two elemental cells.
[0092] According to an advantageous embodiment, an operating regime in exothermic mode is defined for the electrolysis of steam at the cathode of one of the two adjacent elemental cells and an operating regime in endothermic mode is simultaneously performed for the electrolysis of carbon dioxide at the cathode of the other of the two adjacent elemental cells, the heat evolved by the electrolysis of steam being capable of at least partly providing the heat required for the electrolysis of the carbon dioxide.
[0093] Alternatively, an operating regime in exothermic mode is defined for the electrolysis of carbon dioxide at the cathode of one of the two adjacent elemental cells and an operating regime in endothermic mode is simultaneously performed for the electrolysis of steam of the other of the two adjacent elemental cells, the heat evolved by the electrolysis of the carbon dioxide being capable of at least partly providing the heat required for the electrolysis of the steam.
[0094] The invention also relates to the use of the reactor described or of the system described as a methanation reactor.
[0095] The invention also relates to the use of the reactor described as a fuel cell and catalytic reforming reactor, the chamber not being under pressure, the combustible gas recovery tube constituting a combustible gas feed tube and the stacked-cell electrolysis or co-electrolysis reactor constituting an SOFC fuel cell.
[0096] In other words, the conversion processes according to the invention, in particular for methanation, consist essentially in injecting steam under pressure into a chamber, electrolyzing the steam H 2 O or co-electrolyzing the steam H 2 O and carbon dioxide CO 2 at high temperature and performing catalytic conversion into combustible gas in the same chamber maintained under pressure, by placing the reaction zone at a sufficient distance from the electrolysis or co-electrolysis reactor to obtain an optimum gas temperature range for the catalytic conversion. The process according to the invention is advantageously performed by means of the reactor according to the invention.
[0097] In other words, the invention makes it possible to produce methane at a high-temperature water electrolysis pressure that is already tried and tested, typically 30 bar, without having to invest specifically in one or more items of equipment dedicated to pressurization since the leaktight chamber under pressure according to the invention serves both as a chamber for the catalytic conversion and for the electrolysis/co-electrolysis.
[0098] The co-electrolysis of steam and carbon dioxide may advantageously be performed in the stack reactor according to the teaching of the abovementioned application FR 12 62174: steam is fed and distributed to the cathode of one of the two adjacent elemental cells and carbon dioxide is fed and distributed to the cathode of the other of the two elemental cells. This makes it possible to vary at will the H 2 /CO ratio obtained at the outlet before mixing it to constitute the syngas converted into combustible gas in the chamber, and to facilitate the thermal management of the stack of electrolysis cells irrespective of the operating mode (endothermic or exothermic mode), and to do so reversibly as a function of the current cost.
[0099] The advantages of electrolysis of steam under pressure or of co-electrolysis of steam and carbon dioxide combined with a catalytic conversion into combustible gas in the same chamber maintained under pressure, in accordance with the invention, are manifold. Among these, mention may be made of:
use of a single machine with a single chamber to perform both the electrolysis of steam or the co-electrolysis of steam and CO 2 and catalytic conversion into combustible gas, more particularly methanation, which makes it possible to limit the investment; strong integration of the thermal management between electrolysis/co-electrolysis and catalytic conversion in the same chamber when compared with the known processes requiring the sequential use of at least two different reactors; dimensioning of the pressure resistance for a single chamber both for electrolysis/co-electrolysis and for catalytic conversion (methanation). In particular, the catalytic conversion may be performed at high pressure required for electrolysis/co-electrolysis without the need to invest in an additional chamber. The wall(s) constituting the porous partition placed at a distance from the electrolysis or co-electrolysis reactor, for performing step b/ or b′/, in particular methanation, may be of very simple design and of low cost; performing catalytic conversion, in particular methanation, under pressure, which allows operation of the solid catalyst over a wide temperature range and thus introduces a certain level of flexibility into the thermal management. This also makes it possible to perform the catalytic conversion at high pressure, typically the pressure usually encountered in methane gas pipelines, i.e. at 80 bar, without having to make any specific investment. In particular, any compression of the combustible gas, such as methane CH 4 , leaving the chamber according to the invention may thus be dispensed with; direct conveying of the methane obtained into the gas network under pressure if less than 10% unconverted hydrogen remains; possible elimination of any detrimental thermal gradient in the porous partition, by means of the possible concentric arrangement of the porous partition closed on itself around and at a distance from the electrolysis/co-electrolysis reactor, the path of the gas to be converted in the catalyst may be relatively short, even for a large amount of catalyst, which is favorable for the thermal management of the catalytic conversion, such as methanation, which takes place over the entire circumference of the partition. The thickness of the partition containing the solid catalyst may then be relatively low with respect to its other dimensions; better management of the risks associated with the use of the chamber under pressure when compared with the HTE electrolyzers according to the prior art, due firstly to the reduction in the volume of gas required for the same thermal gradient between the electrolysis reactor and the walls delimiting the chamber and secondly to the heat shield function at lower temperature imparted to the porous partition, typically at 400° C. for methanation, with respect to the walls of the chamber whose temperature it is desired to control; additional flexibility for the thermal management of the overall reactor according to the invention by means of the heating brought about by the introduction of the syngas to the inner wall of the porous partition and which is located in an already hot space of the chamber; flexibility of use of the reactor according to the invention since, firstly, it is possible to perform the methanation either via the direct route or via the indirect route by injecting CO 2 and, secondly its operation may be reversed by injecting methane CH 4 , the partition containing the solid catalyst then functioning as a catalytic pre-reformer and the electrolysis reactor of SOEC type functioning as an SOFC fuel cell; in other words, in the context of the invention, the inversion leads to using the partition with the solid catalyst as a reformer and the SOEC electrolysis reactor as an SOFC fuel cell so as to produce electrical current; less consumption of water and less investment in water treatment equipment when compared with sequential HTE electrolysis and methanation according to the prior art. Thus, maintaining the walls delimiting the chamber at a temperature below the water saturation temperature at the given pressure makes it possible to be able to separate the methane produced and the water not converted by condensing this water on said walls. The water thus condensed may then be reinjected into the steam production device of the system (vaporization heat exchanger). Consequently, when compared with a system according to the prior art with the methanation reactor and the water electrolysis reactor separated, investment in a pressurized condenser to obtain dry methane is avoided; depending on the application intended for the use of the methane obtained according to the invention, if the pressure of the chamber and thus of the methane obtained is too high, possibility of expanding the methane and, as a result, in participating in the cooling of the chamber; possibility of liquefying the methane under very high pressure obtained according to the invention by successive expansions for its transportation.
DETAILED DESCRIPTION
[0112] Other advantages and characteristics of the invention will emerge more clearly on reading the detailed description of examples of implementation of the invention given as nonlimiting illustrations with reference to the following figures, among which:
[0113] FIG. 1 is a schematic view showing the operating principle of a high-temperature water electrolyzer;
[0114] FIG. 2 is an exploded schematic view of part of a high-temperature steam electrolyzer comprising interconnectors,
[0115] FIG. 3 is a view in perspective partially cutaway of a reactor according to the invention performing in the same chamber under pressure either high-temperature electrolysis of steam H 2 O or high-temperature co-electrolysis of steam H 2 O and of carbon dioxide CO 2 and methanation using the gas(es) produced by the electrolysis or the co-electrolysis,
[0116] FIG. 4 is a detailed view in perspective partially cutaway of the reactor according to FIG. 3 ,
[0117] FIG. 5 is another detailed view in perspective partially cutaway of the reactor according to FIG. 3 .
[0118] Throughout the present application, the terms “vertical”, “lower”, “upper”, “bottom”, “top”, “below” and “above” are to be taken by reference relative to a reactor for obtaining a combustible gas with its chamber under pressure such that they are in vertical operating configuration. Thus, in an operating configuration, the chamber is arranged vertically with its base at the bottom and the electrolysis or co-electrolysis reactor is arranged with its cells horizontal on its dedicated support.
[0119] Similarly, in the assembly of the present application, the terms “inlet”, “outlet”, “downstream” and “upstream” are to be understood with reference to the direction of circulation of the gases from their entry into the HTE electrolysis or co-electrolysis reactor or into the leaktight chamber under pressure up to their exit therefrom.
[0120] It is pointed out that, in all the FIGS. 1 to 5 , the symbols and arrows for feeding steam H 2 O, for distributing and recovering dihydrogen H 2 and oxygen O 2 , and current, carbon dioxide CO 2 , for distributing and recovering carbon monoxide CO and oxygen O 2 and current, and methane CH 4 are shown for the purposes of clarity and precision, to illustrate the functioning of a steam electrolysis or simultaneous steam and carbon dioxide co-electrolysis reactor that are known and of a methanation reactor according to the invention.
[0121] It is also pointed out that, in FIGS. 3 to 5 relating to a methanation reactor according to the invention, the recovery of oxygen O 2 at the electrolyzer or co-electrolyzer outlet is not shown, for the purposes of clarity.
[0122] It is also pointed out that all the electrolyzers or co-electrolyzers described are of the solid oxide type (SOEC, Solid Oxide Electrolyte Cell) operating at high temperature. Thus, all the constituents (anode/electrolyte/cathode) of an electrolysis cell are ceramic.
[0123] Such constituents may be those of an SOFC fuel cell. The high operating temperature of an electrolyzer (electrolysis reactor) is typically between 600° C. and 1000° C. Preferably, in the context of the invention, a preferred range between 650 and 850° C. and more preferably between 700 and 800° C. is envisaged.
[0124] Typically, the characteristics of an SOEC elemental electrolysis cell in accordance with the invention, of the cathode-supported type (CSC), may be those indicated as follows in table 2 below.
[0000]
TABLE 2
Electrolysis cell
Unit
Value
Cathode 2
Constituent material
Ni-YSZ
Thickness
μm
315
Thermal conductivity
W m −1 K −1
13.1
Electrical conductivity
Ω −1 m −1
10 5
Porosity
0.37
Permeability
m 2
10 −13
Tortuosity
4
Current density
A · m −2
5300
Anode 4
Constituent material
LSM
Thickness
μm
20
Thermal conductivity
W m −1 K −1
9.6
Electrical conductivity
Ω −1 m −1
1 10 4
Porosity
0.37
Permeability
m 2
10 −13
Tortuosity
Current density
A · m −2
2000
Electrolyte 3
Constituent material
YSZ
Thickness
μm
Resistivity
Ω m
0.42
[0125] A water electrolyzer is an electrochemical device for producing hydrogen (and oxygen) under the effect of an electrical current.
[0126] In HTE high-temperature electrolyzers, the electrolysis of water at high temperature is performed using steam. The function of an HTE high-temperature electrolyzer is to convert the steam into hydrogen and oxygen according to the following reaction:
[0000] 2H 2 O→2H 2 +O 2 .
[0127] This reaction is performed electrochemically in the cells of the electrolyzer. As represented schematically in FIG. 1 , each elemental electrolysis cell 1 is formed from a cathode 2 and an anode 4 , placed on either side of a solid electrolyte 3 . The two electrodes (cathode and anode) 2 , 4 are electron conductors, made of porous material, and electrolyte 3 is gas-tight, an electronic insulator and an ion conductor. The electrolyte may in particular be an anionic conductor, more precisely an anionic conductor of O 2− ions and the electrolyzer is then referred to as an anionic electrolyzer.
[0128] The electrochemical reactions take place at the interface between each of the electron conductors and the ion conductor.
[0129] At cathode 2 , the half-reaction is as follows:
[0000] 2H2O+4 e − →2H2+2O 2− .
[0130] At anode 4 , the half-reaction is as follows:
[0000] 2O 2− →O2+4 e − .
[0131] Electrolyte 3 is intercalated between the two electrodes 2 , 4 and is the site of migration of the O 2− ions under the effect of the electrical field created by the potential difference imposed between anode 4 and cathode 2 .
[0132] As illustrated in parentheses in FIG. 1 , the steam entering the cathode may be accompanied by hydrogen H 2 and the hydrogen produced and recovered at the outlet may be accompanied by steam. Similarly, as illustrated with dashed lines, a draining gas, such as air, may also be injected into the inlet to remove the oxygen produced. The injection of a draining gas has the further function of acting as a heat regulator.
[0133] An elemental electrolysis reactor consists of an elemental cell as described above, with a cathode 2 , an electrolyte 3 and an anode 4 and two monopolar connectors which ensure the electrical, hydraulic and thermal distribution functions.
[0134] To increase the flow rates of hydrogen and oxygen produced, it is known practice to stack several elemental electrolysis cells on top of each other, separating them with interconnection devices, usually known as interconnectors or bipolar interconnection plates. The assembly is positioned between two end interconnection plates which support the electrical feeds and gas feeds of the electrolyzer (electrolysis reactor).
[0135] A high-temperature water electrolyzer (HTE) thus comprises at least one, generally a plurality of, electrolysis cells stacked on top of each other, each elemental cell being formed from an electrolyte, a cathode and an anode, the electrolyte being intercalated between the anode and the cathode.
[0136] The fluid and electrical interconnection devices that are in electrical contact with one or more electrodes generally ensure the functions of conveying and collecting electrical current and delimit one or more gas circulation compartments.
[0137] Thus, a “cathode” compartment has the function of distributing electrical current and steam and also recovering hydrogen at the cathode in contact.
[0138] An “anode” compartment has the function of distributing electrical current and recovering the oxygen produced at the anode in contact, optionally with the aid of a draining gas.
[0139] Satisfactory functioning of an HTE electrolyzer requires:
good electrical insulation between two adjacent interconnectors in the stack, otherwise the elemental electrolysis cell intercalated between the two interconnectors will be short-circuited, good electrical contact and a sufficient contact surface between each cell and interconnector, so as to obtain the lowest ohmic resistance between cell and interconnectors, good leaktightness between the two separate compartments, i.e. and cathode, otherwise the gases produced will undergo recombination resulting in a lowering of yield and above all the appearance of hot spots that damage the electrolyzer, good distribution of the gases both at the inlet and on recovery of the gases produced, otherwise there will be a loss of yield, non-uniformity of pressure and temperature in the various elemental cells, or even prohibitive degradation of the cells.
[0144] FIG. 2 shows an exploded view of elementary units of a high-temperature steam electrolyzer according to the prior art. This HTE electrolyzer comprises a plurality of elemental electrolysis cells C 1 , C 2 , of solid oxide type (SOEC) stacked alternately with interconnectors 5 . Each cell C 1 , C 2 , etc. consists of a cathode 2 . 1 , 2 . 2 , etc. and an anode 4 . 1 , 4 . 2 , between which is placed an electrolyte 3 . 1 , 3 . 2 , etc.
[0145] The interconnector 5 is a component made of metal alloy which ensures separation between the cathode compartment 50 and the anode compartment 51 , defined by the volumes between the interconnector 5 and the adjacent anode 4 . 2 and between the interconnector 5 and the adjacent cathode 2 . 1 , respectively. It also ensures the distribution of the gases to the cells. The injection of steam into each elementary unit takes place in the cathode compartment 50 . The collection of the hydrogen produced and of the residual steam at the cathode 2 . 1 , 2 . 2 , etc. is performed in the cathode compartment 50 downstream of the cell C 1 , C 2 , etc. after dissociation of the steam by the latter. The collection of the oxygen produced at the anode 4 . 2 is performed in the anode compartment 51 downstream of the cell C 1 , C 2 , etc. after dissociation of the steam by the latter.
[0146] The interconnector 5 ensures the passage of the current between the cells C 1 and C 2 by direct contact with the adjacent electrodes, i.e. between the anode 4 . 2 and the cathode 2 . 1 .
[0147] In the high-temperature co-electrolyzers HTE, the high-temperature co-electrolysis is performed using steam and carbon dioxide CO 2 . The function of an SOEC high-temperature co-electrolyzer is to transform steam and CO 2 into hydrogen, carbon monoxide and oxygen according to the following reaction:
[0000] CO 2 +H 2 O→CO+H 2 +O 2 .
[0148] A co-electrolyzer 1 may comprise exactly the same solid oxide constituents (SOEC) as an HTE electrolyzer which has just been described. Usually, the steam and carbon dioxide CO 2 are mixed before entering the co-electrolyzer and injected simultaneously into each cathode compartment 50 .
[0149] In order to obtain a variable ratio between the outlet gases produced, H 2 /CO, irrespective of the exothermic or endothermic mode of operation of a given electrolysis cell, the Applicant proposed in the abovementioned patent application FR 12 62174, a novel process for the simultaneous but separate electrolysis of steam and CO 2 .
[0150] More precisely, the process for the high-temperature co-electrolysis of steam H 2 O and carbon dioxide CO 2 according to patent application FR 12 62174 is performed with the electrolysis reactor comprising a stack of elemental electrolysis cells of SOEC type (C 1 , C 2 , C 3 ) each formed from a cathode 2 . 1 , 2 . 2 , 2 . 3 , an anode 4 . 1 , 4 . 2 , 4 . 3 and an electrolyte 3 . 1 , 3 . 2 , 3 . 3 , intercalated between the cathode and the anode, and a plurality of electrical and fluidic interconnectors 5 each arranged between two adjacent elemental cells with one of its faces in electrical contact with the anode of one of the two elemental cells and the other of its faces in electrical contact with the cathode of the other of the two elemental cells. Steam is fed and distributed to the cathode 2 . 1 , 2 . 3 of one (C 1 or C 3 ) of the two adjacent elemental cells (C 1 , C 2 ; C 2 , C 3 ) and carbon dioxide is fed and distributed to the cathode 2 . 2 of the other (C 2 ) of the two elemental cells (C 1 , C 2 ; C 2 , C 3 ).
[0151] In the co-electrolysis reactor according to application FR 12 62174, all the cathode compartments 50 in which circulate the steam H 2 O fed in and the hydrogen H 2 produced communicate with each other. Similarly, all the cathode compartments 50 in which circulate the carbon dioxide CO 2 injected in and the carbon monoxide CO produced communicate with each other, but are completely isolated from the compartments 50 dedicated to the steam H 2 O and to the hydrogen H 2 produced. Finally, the two simultaneous but separate electrolysis reactions both produce oxygen which is collected by all the anode compartments 51 which communicate with each other, irrespective of the reaction concerned.
[0152] At the present time, when it is desired to perform a methanation, two routes are possible. The first is the direct route, with a single reaction according to the following equation:
[0000] CO 2 +4H 2 →CH 4 +2H 2 O.
[0153] The second is the indirect route, with a two-step reaction according to the following equations:
[0000] CO 2 +H 2 →CO+H 2 O
[0000] CO+3H2→CH 4 +H 2 O.
[0154] The methanation is performed in a reactor in which the solid reaction catalyst is present.
[0155] Hydrogen and, where appropriate, carbon monoxide may be produced beforehand either by HTE electrolysis in an electrolysis reactor 1 described with reference to FIG. 1 to 3 , or by high-temperature co-electrolysis also in a co-electrolysis reactor 1 described or in a simultaneous co-electrolysis reactor according to patent application FR 12 62174.
[0156] Thus, the overall process involves the sequential use of two separate reactors, that for electrolysis/co-electrolysis and that for methanation, with, as the major related drawbacks, a heavy investment and a high production cost especially due to the thermal decoupling between the two separate reactors and the need to compress at the outlet of the methanation reactor the methane produced so as to be able to transport it either in dedicated natural gas pipelines at a pressure of 80 bar, or in “medium-pressure” distribution networks at 4 bar.
[0157] To overcome these drawbacks, the inventors of the present invention thought to integrate a methanation reactor with its solid catalyst and a high-temperature steam electrolyzer (SOEC) or a co-electrolyzer of steam and carbon dioxide CO 2 in the same leaktight chamber under pressure, the pressure being that of the steam feed of the electrolyzer/co-electrolyzer, typically at 30 bar. In the context of the invention, if it is desired to have methane at the outlet that is at a higher pressure, the steam feed pressure, and consequently that in the chamber, is at this higher pressure. In particular, it may be desired to have methane at the outlet at a pressure of 80 bar which corresponds to the pressure encountered in methane gas pipelines: the feed pressure of steam and in the chamber is thus, in this case, equal to 80 bar.
[0158] Thus, as illustrated in FIGS. 3 to 5 , the inventors have designed a novel reactor 6 for obtaining methane by heterogeneous catalysis integrating both the electrolysis/co-electrolysis reactor 1 with a stack of SOEC electrolysis cells and the solid catalyst required for the catalytic conversion remote from the electrolysis/co-electrolysis reactor 1 .
[0159] The methanation reactor 6 first comprises an electrolysis/co-electrolysis reactor 1 housed in a leaktight chamber 7 which can be placed under the given pressure at which the feed steam H 2 O arrives in the reactor 1 . As illustrated in FIGS. 3 to 5 , the chamber 7 of the methanation reactor is of generally cylindrical shape of longitudinal axis X and the reactor 1 is centered on this axis X, i.e. the center not shown of each cells C 1 , C 2 , etc. constituting the stack of the reactor 1 is on the axis X.
[0160] As illustrated in FIGS. 3 to 5 , the leaktight chamber 7 comprises a lid 70 , a base 71 , and a side envelope 72 assembled both with the lid 70 and the base 71 . The base 71 and the lid 70 may be assembled on the side envelope 72 via a bolted flange system equipped with a seal.
[0161] To cool the chamber 7 , a cooling circuit is provided consisting of a tube 73 wound in a uniform coil on the outer wall of the side envelope 72 . This cooling circuit 73 may advantageously cool the inner walls 74 delimiting the chamber 7 below the water saturation temperature at the pressure prevailing in the chamber, advantageously below 230° C. at 30 bar. Thus, as explained more precisely below, the unconverted steam may advantageously be condensed on the inner walls 74 and it is thus possible independently to recover the methane produced and the steam by gravity.
[0162] Inside the leaktight chamber 7 is placed a porous partition 8 containing a solid catalyst 80 for converting syngas into methane or a mixture of carbon dioxide CO 2 and hydrogen into methane. The solid catalyst may advantageously be Ni—Al 2 O 3 or Ni—ZrO 2 or that mentioned in publication [2], namely the bimetallic catalyst Ni—Fe/γ-Al 2 O 3 which has excellent catalytic properties for methanation at a pressure of 30 bar.
[0163] As illustrated in FIGS. 3 to 5 , the porous partition 8 consists of two metal walls 81 , 82 each formed from a sheet pierced with a plurality of holes 83 regularly spaced both over the height and over the length of the partition 8 , the height being the dimension of the partition according to the axis X, the length being its circumference around the axis X. In addition to the uniform distribution of the holes 83 , a hole 83 of one of the walls 81 is provided facing a hole 83 of the other of the walls 82 . Conversely, an offset may also be provided between these holes 83 from one wall 81 to the other 82 .
[0164] As also illustrated, the partition 8 is closed on itself forming a cylinder arranged concentrically around and at a distance from the reactor 1 . Finally, a lid 84 different from that of the chamber 7 closes the inner volume delimited by the porous partition 8 . Thus, the presence of the lid 84 makes it possible to force the gas to pass through the catalyst in order to emerge from the chamber. The space separating the two sheets 81 , 82 is filled with conversion catalyst 80 . This catalyst is advantageously in the form of powder which may be introduced into the space between the two sheets 81 , 82 before closure with the lid 84 . Closure of the lid on the sheets may advantageously be performed by welding or by any other mechanical fixing means. The mechanical fixing means do not have to be dimensioned to withstand a substantial force, since this (these) means are not stressed by the pressure prevailing in the chamber 7 . It may be, for example, an attachment of cleat type, a screw through the lid 84 entering the wall 82 .
[0165] As illustrated in FIGS. 3 to 5 , a first support 9 is placed in the chamber 7 to support both the electrolysis or co-electrolysis reactor 1 and the porous partition 8 so as to place them at a distance from the base 71 and from the lid 70 of the chamber 7 . This first support 9 also closes the volume below the partition 8 and of the reactor 1 .
[0166] As illustrated in FIGS. 3 to 5 , a second support 10 is provided, fixed onto the first support 9 , to support only the electrolysis or co-electrolysis reactor 1 so as to place it facing the central portion of the porous partition 8 .
[0167] Preferably, the reactor 1 is halfway up the porous partition 8 , i.e. placed facing a portion located halfway up the height of the walls 81 , 82 . This makes it possible firstly to have a homogeneous thermal gradient in the inner volume delimited by the wall 81 and secondly to have homogeneous distribution of the gases (H 2 and CO or H 2 and CO 2 ) leaving the reactor 1 in this inner volume and thus homogeneous distribution of the gases to be converted into methane during their entry into the catalyst 80 . Needless to say, as explained in detail below, the thermal gradient between the reactor 1 and the porous partition 8 is necessary due to the difference in reaction temperature between, on the one hand, that for the electrolysis of steam or the co-electrolysis of steam and CO 2 , advantageously of about 800° C., and, on the other hand, that for methanation, advantageously about 400° C.
[0168] Thus, a concentric arrangement of the porous partition 8 containing the conversion catalyst 80 around the reactor 1 , a uniform distribution of the holes 83 for passage of the gases (H 2 and CO or H 2 and CO 2 ) leaving the reactor 1 and an arrangement of the reactor 1 halfway up the partition 8 contribute toward a very homogeneous thermal gradient in the inner volume delimited by the partition 8 , its lid 84 and the support 9 and very homogeneous distribution of the gases (H 2 and CO or H 2 and CO 2 ) in this inner volume. The path of the gases in the catalyst 80 may be relatively short, even for a large amount of catalyst present between the walls 81 , 82 , which is advantageous for the thermal management of the methanation reaction over the entire circumference of the partition 8 . The thickness of the partition 8 , i.e. its smallest dimension transversely to the axis X, may thus be relatively small compared to its other dimensions.
[0169] As illustrated in FIGS. 3 to 5 , the partition 8 comprises, in the solid catalyst 80 , a part of the cooling circuit 85 suitable for cooling the catalytic methanation reaction or, in other words, for maintaining a constant temperature, advantageously of 400° C., for said reaction. Specifically, since the methanation reaction is exothermic, the cooling circuit 85 in the catalyst 80 makes it possible to maintain this catalyst at a suitable temperature, preferably close to 400° C. More precisely, the cooling circuit 85 may comprise a tube wound in a regular coil in the space between the inner wall 81 and the outer wall 82 , preferably being close to the inner wall 81 . The cooling circuit 85 may contain an oil as cooling agent and may be a closed circuit.
[0170] As illustrated in FIGS. 3 to 5 , a feed tube 11 is provided to feed steam under pressure and, where appropriate, carbon dioxide to the cathodes of the electrolysis or co-electrolysis reactor 1 . This tube 11 passes from the outside through the base 71 of the chamber 7 and the first support 9 . It is partly wound on itself close to the reactor 1 , preferably around the second support 10 to superheat the steam under pressure and, where appropriate, the carbon dioxide before feeding the cathodes, as explained more precisely below.
[0171] To form steam under pressure, a heat exchanger 12 is provided, placed outside the chamber 7 , and which constitutes a steam production device or steam generator. To do this, liquid water, compressed beforehand to a given pressure, in a tube 13 feeds the steam generator (SG) 12 . In the case of co-electrolysis by the reactor 1 , carbon dioxide CO 2 is introduced via a tube 14 to be mixed in the SG 12 with the steam formed. It may be envisaged to place the steam generator 12 inside the chamber 7 , but, for safety reasons associated with the SG (especially the amount of gas present in the case of depressurization), it is preferable to place it outside as shown.
[0172] As a source of heat for the SG 12 , use may advantageously be made of the closed cooling circuit 85 of the methanation reaction. Thus, as illustrated in FIGS. 3 to 5 , the tube 85 in a regular coil inside the partition 8 and closed on itself passes through the base 71 of the chamber and forms the primary circuit, i.e. that conveying the hottest fluid, of the steam generator-exchanger 12 . In other words, the cooling circuit 85 of the catalysis reaction in the partition 8 advantageously constitutes the heat circuit for vaporizing the liquid water under pressure in the SG-exchanger 12 .
[0173] As illustrated in FIGS. 3 to 5 , a tube 15 for injecting carbon dioxide into the inner volume between the electrolysis reactor 1 and the porous partition 8 is provided. This makes it possible to perform a methanation via the direct route between the hydrogen produced by the electrolysis of the steam under pressure in the reactor 1 and the CO 2 injected via the holes 16 emerging from the tube 15 . Thus, in this direct route, the H 2 +CO 2 mixture passes through the holes 83 of the partition 8 containing the catalyst 80 to be converted into methane. An advantage subsequent to this injection of cold CO 2 via the tube 15 is that of allowing management of the thermal gradient necessary between the electrolysis in the reactor 1 and the catalysis in the catalyst 80 in the partition 8 .
[0174] As illustrated in FIGS. 3 to 5 , a tube 17 is provided for recovering methane produced and a tube 18 is provided for recovering by gravity water condensed on the inner walls 74 delimiting the chamber, each tube 17 , 18 passing through the base 71 of the chamber 7 . So as not to introduce condensed water into the methane recovery tube 17 , this tube protrudes from the base 71 . In contrast, the end of the tube 18 for recovering the condensed water by gravity does not protrude from the base 71 . It may also be envisaged to place the recovery end of the tube 17 on the lid 70 to definitively ensure that said tube 17 does not recover condensates.
[0175] It may be advantageously envisaged to reintroduce the condensed water recovered by the tube 18 into the liquid water inlet 13 at the same pressure, of the SG-heat exchanger 12 .
[0176] As better illustrated in FIGS. 4 and 5 , to achieve uniform diffusion of the carbon dioxide CO 2 injected into the inner volume delimited by the porous partition 8 , the injection tube 15 is wound on itself forming a circle and being pierced with a plurality of holes 16 regularly distributed along the circle.
[0177] This same homogeneous distribution may advantageously be achieved in the inner volume delimited by the porous partition 8 , for the hydrogen H 2 or the syngas CO+H 2 produced in the reactor 1 . Thus, as better illustrated in FIGS. 4 and 5 , a tube 19 for recovering the hydrogen and, where appropriate, the carbon monoxide produced at the cathodes of the reactor 1 is provided. More precisely, this recovery tube 19 is connected to the outlet of the cathode compartments 50 of the reactor 1 and it is wound on itself forming a circle. It is pierced with a plurality of holes 20 regularly distributed along the circle to homogeneously diffuse the hydrogen and, where appropriate, the carbon monoxide in the inner volume delimited by the porous partition 8 .
[0178] The functioning of the reactor 6 and methanation system that has just been described will now be indicated more precisely, in reference with a nominal operating point. The operating conditions are as follows:
injection of liquid water at 20° C., and compressed to a pressure of 30 bar by the tube 13 into the steam generator 12 ; leaktight maintenance at a pressure of 30 bar of the chamber 7 and maintenance at a constant temperature below 230° C. walls 74 ; removal of the steam, where appropriate mixed with CO 2 injected at 14 , from the SG 12 by the tube 11 at 300° C., at the same pressure of 30 bar; superheating of the steam to 300° C. and 30 bar, where appropriate mixed with CO 2 injected at 14 , in the part wound on itself of the tube 11 close to the reactor 1 to reach a temperature of 800° C. at the inlet of this reactor; when the steam removed in the tube 11 does not contain any CO 2 , then injection of CO 2 at room temperature via the tube 15 with holes 16 ; maintenance at constant temperature at about 400° C. of the partition 8 ; passage of the H 2 +CO+H 2 O mixture removed by the tube 19 at the outlet of the co-electrolysis reactor 1 , and/or with CO 2 injected via the tube 15 , into the porous partition 8 ; methanation reaction at 400° C. in the partition 8 ; removal via the holes 83 of the outer wall 82 of the methane CH 4 produced and of the water not converted in the HTE and formed by the methanation in the volume delimited between the partition 8 and the chamber 7 ; condensation of the water on walls 74 delimiting chamber 7 ; recovery of the methane produced at a pressure of 30 bar via the tube 17 ; recovery by gravity via the tube 18 of the liquid water condensed and at a pressure of 30 bar;
[0191] reinjection of the liquid water recovered at 30 bar into the steam generator 12 .
[0192] Under non-nominal operating conditions, it may be envisaged to inject CO 2 both via the tube 15 (direct route) and via the tube 14 (indirect route).
[0193] The rise of the steam under pressure from 300° C. to 800° C. close to the electrolyzer (co-electrolyzer) 1 may take place solely by the exothermic evolution of the reaction in this reactor. A heating system not shown may also be used.
[0194] The reactor 6 and methanation system that have just been described are simple to produce with a low investment cost. In particular, all the walls 81 , 82 and lid 84 of the partition 8 , the constituents 70 , 71 , 72 of the chamber 7 , the supports 9 , 10 , the tubes 11 , 13 , 14 , 15 , 17 , 18 , 19 , 73 , 85 may be made using a relatively inexpensive metal, such as stainless steel 316L. Needless to say, care will be taken to select a suitable metal for the parts that need to withstand the high temperatures of the electrolysis/co-electrolysis, typically 800° C. Thus, for at least the parts of the tubes 11 , 19 inside which circulate gases at 800° C. and 30 bar, a production with nickel-based alloys may be envisaged.
[0195] The reactor 6 and methanation system that have just been described allow a lower production cost than those of the prior art, especially due to the optimized thermal coupling between the two reactions (electrolysis/co-electrolysis and methanation) in the same chamber 7 under pressure and due to the absence of methane compression equipment, the absence of a pressure chamber specific to methanation, the absence of a condenser at 30 bar, all these functions being performed de facto in the chamber 7 .
[0196] The invention is not limited to the examples that have just been described; it is especially possible to combine together features of the illustrated examples within variants not illustrated.
[0197] Thus, whereas in the detailed implementation example, the reactor 6 and system are envisaged for performing methanation, they may just as equally be envisaged for obtaining methanol CH 3 OH; DME or diesel. Irrespective of the combustible gas that it is sought to obtain, the following preferred parameters may remain identical:
liquid water feed pressure equal to the pressure of the chamber 7 , of about 30 bar, electrolysis or co-electrolysis temperature of about 800° C. to produce H 2 +CO.
[0200] On the other hand, depending on the type of combustible (fuel) targeted, the H 2 /CO ratio, the choice of the catalyst 80 and the temperature for the catalysis, i.e. in the porous partition 8 , are different. For this last parameter, the partition temperature 8 may be about 400° C. for the production of methane CH 4 , and about 250° C.-300° C. for methanol CH 3 OH and DME.
REFERENCES CITED
[0000]
[1]: Fabien Ocampo et al., “ Methanation of carbon dioxide over nickel - based Ce 0.72 Zr 0.28 O 2 mixed oxide catalysts prepared by sol - gel method ”, Journal of Applied Catalysis A: General 369 (2009) 90-96;
[2]: Dayan Tiang et al., “ Bimetallic Ni—Fe total - methanation catalyst for the production of substitute natural gas under high pressure ”, Journal of Fuel 104 (2013) 224-229. | The invention relates to a novel reactor design, wherein the pressurised chamber contains both a high-temperature electrolysis (HTE) reactor with elementary electrolysis cell stacking for producing either hydrogen or a synthesis gas (“syngas” for a H 2 +CO mixture) from water vapour H 2 O and carbon dioxide C0 2 , and at least one catalyst arranged at a distance and downstream of the outlet of the electrolyser for converting the previously produced synthesis gas into the desired combustible gas, by means of heterogeneous catalysis, the synthesis gas having being produced either directly from the electrolysis reactor or indirectly by mixing the hydrogen produced with carbon dioxide C0 2 injected into the chamber. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention.
The invention relates to an apparatus for human physical exercise, and, more particularly, to an apparatus suitable for simultaneous upper and lower body exercise and providing for workload distribution between the body parts.
2. Description of the Prior Art.
A variety of stationary exercise machines are known to the art. Examples of such machines include stationary rowing machines and stationary bicycles. These machines typically simulate a common human activity, such as rowing or bicycling. They lack somewhat in adaptability to specialized exercise needs, and in flexibility to accommodate properly to the physical size of the user.
Rowing, for example, is usually a combined upper and lower body exercise, especially where a sliding seat is provided for the rower. Rowing absorbs work from a large muscle mass, including the major muscles of the arms, torso and legs, in a bilaterally symmetrical, rhythmic pattern of movement. A bilaterally symmetric pattern of movement is one that is identical and simultaneous between the sides of the body. Rowing is generally considered to be an excellent exercise, both for cardiovascular benefits as well as overall conditioning. However, rowing has disadvantages for some individuals, such as patients undergoing rehabilitative therapy, who cannot match the range of movement required by the exercise. The rigid definition of the rowing movement does not allow the exerciser to change muscle sets to meet the total intensity level required or to compensate for limited mobility in certain joints.
Another disadvantage of rowing is a high perceived effort required to achieve a given workout intensity level. This high perceived effort results from a number of factors. Rowing imposes an extreme hip and torso flexion at the beginning of each power stroke. The extreme flexion increases intrathoracic pressures which affect cardiac output and make breathing more difficult. Moreover, the workload is imposed in an on and off pattern, on during the expanding power stroke and off during the relaxation phase. The portion of the total workload concentrated in the power strokes is thus large. In addition, rowing imposes a substantial amount of lower back stress on the user.
Stationary bicycles avoid the stop and start sensation of a rowing machine. However, stationary bicycles have their own disadvantages. Cycling does not distribute the workload, but confines it to the leg muscles. Obviously, the user cannot change muscle sets or the pattern of the exercise and maintain the same overall intensity of exercise. Also, stationary bicycles have typically used perch type seats, influenced by conventional safety bicycles, as an exercise position. This position is not usually comfortable to the infrequent cyclist, and tends to contribute to a feeling of instability on the machines. The perch type saddle contributes to saddle sores and to a relative lack of stability in a nonmoving bicycle.
A handful of prior art devices have attempted to combine a rowing or other type of upper body exercise with a cycling exercise. One prior art device, taught in U.S. Pat. No. 4,188,030, issued Feb. 12, 1980, provides a stationary bicycle with a pair of exercise arms which are linked to the mechanical movement of the cycling exercise. A user can employ the arms or the cycling pedals to drive the movement. Resistance is applied to the movement to increase the workload. However, linkage of the mechanical movements rigidly defines the range of movement of the exercises. In addition, the device taught is substantially a conventional stationary bicycle which has exercise arms. It retains the perch position common to conventional exercise cycles.
Another prior art device is taught in U.S. Pat. No. 4,729,559, issued on Mar. 8, 1988. It includes exercise arms which are mechanically independent of a cycling exercise. However, the device does not include a way of determining the workload distributed between the cycling exercise and the upper body exercise. The device retains perch type seating common to other stationary bicycles.
Exercise, when appropriately administered, can elicit any one, or a combination, of many beneficial effects. These effects include increased cardiovascular efficiency and endurance, muscle strength and tone, and control of weight. Three different and quantifiable measurements of an individual's exercise may be made which relate to attaining the beneficial effects. These include a measurement of intensity comprising the level of power output of the individual, duration of an individual's bout of exercise and frequency of bouts of exercise. Intensity and duration may be used as factors in a calculation of total work done or energy expended in a particular bout, i.e., calories expended. The above noted benefits are enjoyed only when exercise is persisted in at appropriate intensity levels. The present invention is directed to maintaining a higher degree of perceived comfort and ease, and contributing to greater exercise frequency, while guiding the user in maintaining an appropriate level of intensity in individual bouts.
SUMMARY OF THE INVENTION
The exerciser of the present invention provides a cycling action for exercise of the lower body and a pair of exercise arms for upper body exercise. By providing for upper and lower body exercise, the workload on the user is distributed over a large number of muscle groups and muscle actions. Moreover, the upper body exercise of the present invention is more than a rowing exercise in the sense that it is not limited to a bilaterally symmetrical pattern of movement as described above. The mechanical movements of the present invention are adapted to apply resistance to each of the pair of exercise arms in both directions of movement. The arms may be moved entirely independently of one another, and may be moved for only a fraction of their overall travel. The mechanical movement allows two additional arm and torso exercises. The first additional exercise is termed "unilateral reciprocation" and involves moving the arms oppositely in a rhythmical pattern. The second additional exercise is termed "independent unilateral movement", where no particular relationship exists between movements of the arm and, in fact, one arm may remain motionless.
An important advantage of the present invention is an adjustable recumbent seating position. The user's reclined position provided by the recumbent seat reduces the adverse effects of gravity and posture on venous blood return. This reduces blood pressure during exercise, which is an important consideration for individuals in cardiac rehabilitation programs and also contributes to a lower level of perceived exertion. The recumbent position provides the user with a comfortable position posturewise during the course of their exercise. The recumbent seat also opens the hip position of the user which reduces pressure on the diaphragm, leading to fuller, more comfortable breathing. The recumbent type seat also offers greater stability for a user than a perch type seating arrangement. Greater comfort and reduced perceived effort tend to contribute to greater duration and greater frequency of exercise.
The exercise machine of the present invention guides exercise at a plurality of intensity levels. The mechanical movements for the lower and upper body are adapted to drive independent electrical generators. Variable resistor banks are provided for applying loads across these generators. The user may select a program of exercise which sets the total load to be met and the proportion of the load to be met from the upper body and the lower body.
The exercise device of the present invention also provides for tachometers on the generators to allow determination of work expended and compares such expenditure output against targets to determine the intensity of the workout. The machine also times the workout. Simplification of maintenance is provided by powering the electronics from the generators. Thus the effort of the user powers the electronics.
The onboard computer uses the data gathered to run a display indicating to the user the intensity of the workout and the proportions of the workout being met by the upper body and the lower body. The readouts guide the user to an appropriate level of work. The work expended in each exercise is monitored and compared to targets. This directs distribution of the total effort between the major body parts, reducing the perceived total effort required.
The exercise machine accordingly allows exercise which is physically comparable to cross-country skiing. It allows the user to switch back and forth between muscle groups to meet the intensity level required and it varies the intensity level required from moment to moment.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the exercise machine of the present invention;
FIG. 2 is a cross sectional view of the mechanical movements of the present invention;
FIG. 3 is a top plan view of the mechanical movements of the present invention;
FIG. 4 is a front view of the exercise machine of the present invention;
FIG. 5 is a schematic of the control and load circuitry of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates the external components of exercise machine 10 of the present invention. Exercise machine 10 includes an external body 12 which houses the mechanical movements of machine 10. An adjustable recumbent saddle 18 is mounted on a positioning track 20 to allow adjustment of the exercise position for a user. Recumbent saddle 18 is positioned by a user with respect to pedals 22 and 24 so as to enhance efficiency and comfort. Pedals 22 and 24 are mounted for rotation and are accessible to a user seated in recumbent saddle 18. Pedals 22 and 24 provide the cycling action of exercise machine 10.
A pair of exercise arms 14 and 16 are disposed on opposite sides of exercise machine 10, accessible to a user seated in recumbent saddle 18. Right exercise arm 14 includes an arm extension 38 which may be adjusted in height by adjustment knob 34. Hand grip 40 is provided for gripping by the user. Similarly, left exercise arm 16 includes an arm extension 36. Hand grip 42 for gripping by the user with his left hand is provided at the upper end of extension 36. An adjustment knob 32 (shown in FIG. 4) may be used to adjust the position of extension 36.
A user display and control panel 28 is provided for easy access and viewing by a user seated in recumbent saddle 18. User display and control panel 28 exhibits such information as exercise intensity level, proportion of intensity level being met, distribution of load between lower and upper body, terrain profile of the cycle exercise for lower body, estimated calories consumed and other information of interest to the user. Panel 28 also provides directions for changing the exercise program through control buttons accessible on the panel.
The position of recumbent saddle 18 is adjustable along track 20. Track 20 guides the positioning of recumbent saddle 18. This allows the long-legged user to adjust the saddle position to maintain the same open hip posture and body angle with respect to the cycling action. Recumbent saddle 18 supports body weight over a number of points and allows ease in mounting and dismounting exercise machine 10.
FIG. 2 illustrates the mechanical movements of the present invention. The mechanical movements include cycling drive train 53 and exercise arm drive train 63. Exercise arm drive train 63 is mechanically coupled to two substantially identical translation to rotation mechanisms 73 and 77 (mechanism 77 being shown in part in FIG. 3). The description herein of mechanism 73 is exemplary of both mechanisms.
The exercise device of the present invention comprises a frame 30 adapted to support the exercise device on a surface. Cycling drive train 53 includes pedals 22 and 24 described in reference to FIG. 1, pedal 22 being visible in FIG. 2. Pedal 22 is pivotally mounted on disc 26, which is connected to drive crankset 50. Pedal 24 is similarly linked to drive crankset 50. Crank set 50 guides movement of the user's feet in a rotational direction to simulate bicycling. Crank set 50 is trained with an intermediate reduction gear 54 by chain 52. Intermediate reduction gear 54 is trained with a final drive gear 58 by chain 56. Final drive gear 58 is mounted on the axle to drive generator 60, which produces direct current electric power in response to movement of the cycling action.
Right translation to rotation mechanism 73 is disposed on the starboard side of frame 30. Mechanism 73 includes right exercise arm 14, which is linked to right inboard lever arm 62 on fulcrum 64 providing a lever actuated by a user.
Lever arm 62 supports an elongated clustered wheel carrier 92 for reciprocating movement. A tension spring 93 is linked between arm 62 and cluster wheel carrier 92 so as to pull cluster wheel carrier 92 toward vertical alignment with lever arm 62. Clustered wheel carrier 92 supports a pair of separated groups or clusters of sprockets 88 and 90. One cluster is designated the primary cluster 88 and the other cluster is designated the complementary cluster 90. The sprockets of clusters 88 and 90 comprise built-in Torrington-type clutches permitting rotation in one direction only. The three sprockets in each cluster are further disposed at the vertices of a regular triangle to engage a chain 82 on either side thereof.
Chain 82 trains drive gear 78 with idler gear 80. The upper chain lead between idler 80 and drive gear 78 is termed primary lead 84 of chain 82. Primary lead 84 is laced through primary sprocket cluster 88, passing under the two outboard sprockets and over the intermediary sprocket. The outboard sprockets are adapted to rotate freely clockwise. The intermediate sprocket rotates counterclockwise. Thus chain 82 passes freely in the direction of primary lead 84 from idler 80 to drive gear 78.
The lower chain lead between drive gear 78 and idler 80 is termed the complementary chain lead 86 of chain 82. Complementary lead 86 is laced on complementary sprocket cluster 92, passing over the outboard sprockets and under the intermediary sprocket. The outboard sprockets can rotate in the clockwise direction only, intermediary sprocket can rotate in the counterclockwise direction only. Thus chain 82 passes through the cluster in the direction of complementary lead 86 only, that is, from drive gear 78 to idler 80.
Reciprocating movement of cluster wheel carrier 92, without regard to initial direction, results in movement in a single direction of chain 80. Movement of carrier 92 toward drive gear 78 is termed the primary cycle. As the movement of carrier 92 in the primary cycle matches the velocity of chain 82 in primary lead 84, the sprockets of primary sprocket cluster 88 clutch and kinetic energy may be transferred through the sprockets to chain 82. As the speed of carrier 92 in the complementary cycle matches the velocity of chain 82 in complementary lead 86, the sprockets of complementary sprocket cluster 90 clutch and kinetic energy may be applied to chain 82 from lever arm 62. Movement of either sprocket against its respective lead results in the chain passing through the cluster without substantial hindrance.
The operation of rotation to translation mechanism 77 is substantially similar and is not elaborated on further here.
Reciprocating movement of cluster carrier 92 results in counterclockwise rotation of drive gear 78. This in turn puts drive train 63 into motion. Drive gear 78 is coupled to rotate crankset 76. A chain 74 trains crankset 76 to intermediate reduction gear 72. Intermediate reduction gear 72 is coupled to final drive pulley 68 by timing belt 70. Drive pulley 68 is linked to D.C. generator 66.
Accordingly, as exercise arm 14 is pulled toward a user seated in saddle 18, energy may be transferred from primary cluster 88 to chain 82 in primary lead 84. As exercise arm 14 is pushed away from a user seated in saddle 18, energy may be transferred from cluster set 90 to chain 82 in complementary lead 86. In either event, energy is transferred from the user to drive generator 66.
Recumbent saddle 18 is supported on a carriage 48 mounted on track 20. The position of carriage 48 on track 20 is locked by mechanism 46 which may be released for movement by lever 44. Also shown are a variable resistor pack 94 and heat sink 96, the operation of which is explained below.
FIG. 3 is a top partial cutaway view of frame 30. A translation to rotation conversion movement 77 is provided on the port side of frame 30. Conversion movement 77 is substantially identical to movement 73 on the starboard side of exerciser 10. Left rowing arm 16 is part of a lever mounted on fulcrum 110. The lever includes an inboard lever arm (not shown) which supports cluster carrier 112. Cluster carrier 112 supports primary wheel cluster 106 and complementary wheel cluster 108 to engage left chain 102. Chain 102 trains idler gear 127 with drive gear 128. Idler wheel 127 is linked with idler wheel 80 by axle 98. Drive gear 128 is linked with drive gear 78 by axle 100. Axle 100 is a portion of a crankset 76 for driving drive chain 63. Linkage of the translational movements to rotational movements 73 and 77 permits arm exercises to be carried out with one arm only. Actuation of the movement by one arm will simply result in the chain associated with the opposite arm moving across its corresponding freewheeling clusters.
FIG. 4 is a front view of the frame and the cycling movement of the present invention. Left exercise arm 16 is disposed on fulcrum 110 and exercise arm 14 on fulcrum 64. As may be seen with reference to FIGS. 3 and 4, exercise arms 14 and 16 are coaxial and provide for rowing action in parallel planes.
FIG. 5 illustrates the load distribution system of the present invention in schematic representation. DC generators 60 and 66 are coupled to tachometers 118 and 116 respectively. Measurements therefrom are transmitted to a microcomputer 120 housed in display panel 28. DC generators 60 and 66 are connected across a variable resistor pack 94 which applies selected loads independently to generators 60 and 66 at the direction of microcomputer 120. Heat produced in variable resistor pack 94 is dissipated through a heat sink 96. Microcomputer 120 provides control signals to variable resistor pack 94 to vary the instantaneous resistance shown in generators 60 and 66. Resistances may be varied to determine the total load and the variability of the load to provide simulated terrain profiling. Microcomputer 120 is also coupled to generators 60 and 66 through a power supply 122 and derives all power for its operation by actuation of generators 60 and 66. This allows elimination of a battery from within the exercise device or for any need to connect the device to an external power source. Microcomputer 120 drives user display 28 and receives control inputs from display 28 to determine the program it will operate.
A person exercising on the exerciser of the present invention benefits from the improvements thereof in several respects. Where an objective of exercise is weight control or cardiac efficiency, the workload distribution system lowers the perceived effort, enabling the user to maintain the required exertion level for a longer time. Microcomputer 120 determines the exercise intensity level required, and sets the resistor values across the respective generators to elicit the intensity level and to distribute the load between upper body and lower body. Displays indicate to the user the load breakdown and whether the user is meeting the total output demanded. The user selects the most comfortable distribution of load. The lower perceived level of work contributes to regular use of the machine.
Recumbent saddle 18 allows exercisers to easily mount and dismount from exercise machine 10. Movement of either exercise arm provides indication and power to microcomputer to start and execute a startup program for use by the user if desired. After start-up, microcomputer 120 can be kept in operation by actuation of either the cycling action or the upper body action. The exerciser may select from ten effort levels and can allocate the proportion of the effort required for either lower or upper body from 0% to 100%. The duration of a bout is set by default at fifteen minutes. Readouts will indicate to the users various indicia of their workout level as well as their progress toward completion of the bout.
The electronically variable load also allows terrain simulation for the cycling portion of the exercise. This contributes to maintaining the interest of the user.
The exercise arms provide for independently selectable ranges of movement for each arm which has therapeutic value.
Because the machine is powered by effort of the individual, no battery or external power connection is needed.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | Disclosed is an exercise device providing mechanical actions for independent or simultaneous exercise of the upper and lower body of a human user. Each action incorporates a mechanical movement converting output of the user to rotational motion and thereby powering one of two electrical generators. An exercise controller selects loads to be applied to the generators. The loads are coupled by the mechanical movements back to the user to provide resistance to the exercise effort. The exercise controller drives an electronic display which informs the user of his or her intensity of effort as well as the proportion of that effort being met through exercise of the upper body and the part being met through exercise of the lower body. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] This invention relates to compositions of matter, methods, and apparatuses useful in producing stable high solids colloidal silica and uses thereof. As described in U.S. Pat. Nos. 6,486,216, 6,361,653, 5,840,158, 6,361,652, 6,372,805, and US Published Patent Application 2011/0250341 A1, Colloidal silicas, are aqueous systems with silica microparticles suspended within them. Colloidal silicas have been found to be useful in numerous fields of application dependent on the particle size including the manufacture of silicon wafers and carbonless papers, as anti-soilants, lubricants, high temperature binders, abrasives, moisture absorbers, and abrasion resisters. In particular as described for example in U.S. Pat. Nos. 4,753,710, 4,913,775, 4,388,150, 4,385,961, 5,182,062, and 5,098,520, colloidal silicas have been found to have an especially useful number of applications in the papermaking industry, especially in enhancing the retention and drainage of paper pulps.
[0004] The nature of colloidal silicas unfortunately subjects them to a number of limiting constraints. When dosing a colloidal silica two factors are of large significance, average particle size (usually measured in surface area) and the percentage of the aqueous system that the particles comprise (solids %). For a given application there is an ideal particle size at which the colloidal silica will be most effective. Often a user would prefer to apply as high a solids % at that particle size as possible. However applying that ideal particle size is often impractical because the colloidal silica is not stable at that size at a high solids % for a sufficient length of time.
[0005] Stability of colloidal silicas is very important. If the colloids are not stable they can only be used during a very narrow window of time. This narrowness forces numerous costs and inconveniences on users in terms of among other things: storage costs, preparation costs, equipment requirements, and the need to constantly replace no longer stable colloids. The stability of colloidal silica is inversely proportional to both solids % and to particle size. As a result a silica colloid of a given particle size will only be stable for a significant period of time (for example >3-6 months) up to a particular solids % which is usually lower than the ideal amount. When a. colloid's solids % exceeds that level, the silanol groups on various microparticles interact with each other and form interlocked complexes which cause the aqueous system to become a highly viscous sludge which is no longer effective for its intended use. In addition, other factors can impair the stability of the microparticles. As a result users are often forced to choose between more stable colloidal silicas that have a lower solids % than they want or they must use colloidal silicas having a desired solids % but which are less stable than desirable.
[0006] Thus there is a clear need for and utility in an improved method of producing stable high solids colloidal silica. The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. §1.56(a) exists.
BRIEF SUMMARY OF THE INVENTION
[0007] At least one embodiment of the invention is directed towards a method for improving the performance of colloidal silica. The method comprises the steps of: providing a colloidal silica, and separating charged particles from the colloid. The separation is conducted to a degree such that cross-linkage inducing interactions between charged particles and silanol groups on the silica decreases but not to such a degree that cross-linkage inducing interactions between silanol groups increases. The separation increases the particle size of the colloid by at least 5% without impairing the S-Value, or stability of the colloid.
[0008] The colloid may be applied to a papermaking system and it may be at least as effective in its application as a similar colloid that has not undergone the separation. The separated particles may be particles that were introduced to the colloid during a heel or resin based formation process. The colloidal particles may have has a surface area of from about 700 m 2 /g to about 1100 m 2 /g, and may have a percent by weight SiO 2 solids level of at least 15. The separation may be accomplished using a dilution filtration process in which the filtration is at least in part ultrafiltration. The dilution may occur at a different time than the filtration and/or may overlap at least in part. The rate of the dilution may be such that fluid passes through a filter in the filtration process at a net rate no faster than the rate the net rate that the charged particles dissociate from colloidal droplets. The method may comprise repeatedly diluting then filtering the colloid, the diluting characterized by decreasing the solids % by between 30 to 80% of the solids % present at the start of the process, the filtering, except for a final filtration step, comprises returning the solids % to within 10-60% of the solids % present at the start of the process. The dilution may not commence until the rate of the fluid passing through the filter slows. The colloid may be applied to a papermaking process as part of a retention and drainage program and/or may be used in conjunction with polymeric flocculants and/or cationic starch with or without the addition of a coagulant and there is no loss of effectiveness or unwanted side effects when compared to a similar colloid that has not undergone the separation. The degree to which impurities have been removed from the colloid may be measured by correlating it to a measurement of the change in the conductivity of the colloid. The removal of impurities may proceed until the colloidal system has a conductivity of between 4000 μS/cm to 7000 μS/cm.
[0009] Additional features and advantages are described herein, and will be apparent from, the following Detailed Description.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The following definitions are provided to determine how terms used in this application, and in particular how the claims, are to be construed. The organization of the definitions is for convenience only and is not intended to limit any of the definitions to any particular category
[0011] “Colloid” or “Colloidal System” means a substance containing ultra-small particles substantially evenly dispersed throughout another substance, the colloid consists of two separate phases: a dispersed phase (or internal phase) and a continuous phase (or dispersion medium) within which the dispersed phase particles are dispersed, the dispersed phase particles may be solid, liquid, or gas, the dispersed-phase particles have a diameter of between approximately 1 and 1,000,000 nanometers, the dispersed-phase particles or droplets are affected largely by the surface chemistry present in the colloid.
[0012] “Colloidal Silica” means a colloid in which the primary dispersed-phase particles comprise silicon containing molecules, this definition includes the fa teachings of the reference book: The Chemistry of Silica: Solubility, Polymerization, Colloid and Surface Properties and Biochemistry of Silica , by Ralph K. Iler, John Wiley and Sons, Inc., (1979) generally and also in particular pages 312-599, in general when the particles have a diameter of above 100 nm they are referred to as sols, aquasols, or nanoparticles.
[0013] “Colloidal Stability” means the tendency of the components of the colloid to remain in colloidal state and to not either cross-link, divide into gravitationally separate phases, and/or otherwise fail to maintain a colloidal state its exact metes and bounds and protocols for measuring it are elucidated in The Chemistry of Silica: Solubility, Polymerization, Colloid and Surface Properties and Biochemistry of Silica , by Ralph K Iler, John Wiley and Sons, Inc., (1979).
[0014] “Microparticle” means a dispersed-phase particle of a colloidal system, generally microparticle refers to particles that have a diameter of between 1 nm and 100 nm which are too small to see by the naked eye because they are smaller than the wavelength of visible light.
[0015] “S-Value” means the measure of the degree of microaggregation of colloidal materials, it can be obtained from measurements of viscosity of the colloidal system and is often related to the performance of the colloidal end product, its exact metes and bounds and protocols for measuring it are elucidated in The Chemistry of Silica: Solubility, Polymerization, Colloid and Surface Properties and Biochemistry of Silica , by Ralph K Iler, John Wiley and Sons, Inc., (1979).
[0016] “Solids %” means the portion of an aqueous system by weight that is silica bearing particles of the continuous phase.
[0017] “Silanol” means a functional group on a silicon bearing molecule with the connectivity of Si—O—H.
[0018] “Separation” means a mass transfer process that converts a mixture of substances into two or more distinct product mixtures, at least one of which is enriched in one or more of the mixture's constituents, it includes but is not limited to such processes as: Adsorption, Centrifugation, cyclonic separation, density based separation, Chromatography, Crystallization, Decantation, Distillation, Drying, Electrophoresis, Elutriation, Evaporation, Extraction, Leaching extraction, Liquid-liquid extraction, Solid phase extraction, Flotation, Dissolved air flotation, Froth flotation, Flocculation, Filtration, Mesh filtration, membrane filtration, microfiltration, ultrafiltration, nanofiltration, reverse osmosis, Fractional distillation, Fractional freezing, Magnetic separation, Precipitation, Recrystallization, Sedimentation, Gravity separation, Sieving, Stripping, Sublimation, Vapor-liquid separation, Winnowing, Zone refining, and any combination thereof.
[0019] “Ultrafiltration” means a process of filtration in which hydrostatic pressure forces a filtrate liquid against a semipermeable membrane, suspended solids and solutes of high molecular weight are retained, while water and low molecular weight solutes pass through the membrane, it is used in industry and research for purifying and concentrating macromolecular (10 3 -10 6 Da) solutions, it includes but is not limited to microfiltration, nanofiltration or gas separation, it may be applied in cross-flow or dead-end mode and separation in ultrafiltration may undergo concentration polarization the exact metes and bounds and protocols for applying and categorizing ultrafiltration are elucidated in the scientific reference: Ultrafiltration and Microfiltration Handbook, Second Edition , by Munir Choyan, Published by CRC Press LLC, (1998).
[0020] “Droplet” means a mass of dispersed phase matter surrounded by continuous phase liquid, it may be suspended solid or a dispersed liquid.
[0021] “Particle Size” means the surface area of a single droplet.
[0022] “Dilution Filtration” means a process in which a material undergoing a filtration process is also being diluted by the addition of liquid to the material, dilution filtration can be simultaneous (the filtration and dilution occur at the same time) staged (the dilution and filtration processes occur one after the other, and/or both and can have one or more relative rates (liquid can be removed from the material by the filtration process faster, slower and/or at the same rate as liquid is added by the dilution process).
[0023] “Interface” means the surface forming a boundary between two or more phases of a liquid system.
[0024] “Papermaking process” means any portion of a method of making paper products from pulp comprising forming an aqueous cellulosic papermaking furnish, draining the furnish to form a sheet and drying the sheet. The steps of forming the papermaking furnish, draining and drying may be carried out in any conventional manner generally known to those skilled in the art. The papermaking process may also include a pulping stage, i.e. making pulp from a lignocellulosic raw material and bleaching stage, i.e. chemical treatment of the pulp for brightness improvement.
[0025] In the event that the above definitions or a description stated elsewhere in this application is inconsistent with a meaning (explicit or implicit) which is commonly used, in a dictionary, or stated in a source incorporated by reference into this application, the application and the claim terms in particular are understood to be construed according to the definition or description in this application, and not according to the common definition, dictionary definition, or the definition that was incorporated by reference. In light of the above, in the event that a term can only be understood if it is construed by a dictionary, if the term is defined by the Kirk - Othmer Encyclopedia of Chemical Technology, 5th Edition, (2005), (Published by Wiley, John & Sons, Inc.) this definition shall control how the term is to be defined in the claims.
[0026] At least one embodiment of the invention is a stable silica colloid whose dispersed phase microparticle has a surface area of from about 700 m 2 /g to about 1100 m 2 /g, and having a percent by weight SiO 2 solids level of from about 10 percent to 30 percent preferably 15 percent to about 25 percent. The dispersed phase microparticle differs from prior art microparticles by undergoing a separation process which improves its stability.
[0027] Colloidal silica contains a number of compositions of matter other than silica bearing molecules, the carrier fluid of the continuous phase, and additives such as emulsifiers or flocculants that aid in the maintenance of the colloid. These particles include salt ions, acids, and bases, which were used to create the silica bearing compounds and/or to condition them to remain in a colloidal state. Once colloidal however many of these vestiges are impurities that are no longer required and to an extent impair the stability of the colloid. As a result, at least partial removal of the impurities helps to reduce reactivity between the impurities and the silanol groups on the silica bearing compounds.
[0028] In at least one embodiment the separation process is only a partial removal of impurities. While some impurities have a tendency to react with or facilitate reaction with the silanol groups they also tend to mediate and impair silanol-silanol reactions on adjacent silica-bearing compounds. As a result a fine equilibrium is achieved by removing some but not all of the impurities from the colloidal system.
[0029] The separation may be achieved by any form of separation known in the art. In at least one embodiment the separation method is an ultrafiltration method conducted during filtration-dilution conditions, Many of the impurities are so fine in size that they can only be removed utilizing ultrafiltration techniques. Unfortunately, as can be seen in the provided Examples, applying an ultrafiltration process to the colloid results in a less stable colloid. This is because the charge balancing environment results in their disassociating and flowing into the filtration membrane slower than the carrier fluid of the continuous phase does. As a result additional fluid must be added to the continuous phase to facilitate the removal
[0030] In at least one embodiment the distinct filtration and dilution applications applied to the colloid are conducted: simultaneously, sequential, and/or are performed with differing rates of filtration and dilution. In at least one embodiment a stable colloid having a starting solids % is diluted so the solids % decreases by between 30 to 80%. Then the colloid is concentrated/filtered until the solids percent returns to within 10% of the starting solids %. Then it is again diluted to decrease by between 30 to 80%. And finally it is filtered again to achieve a weight % which is between 30 to 80% greater than the starting solids % and which is less likely to gel than it was at the starting solids % and it is no less stable. In at least one embodiment the microparticle surface area is greater than 700 m 2 /g.
[0031] In at least one embodiment the degree of removal of charged impurities present in the colloid can be accomplished by measuring the conductivity of the colloid both before and after any filtration or concentration step is performed. As many of the impurities are ionic, removal of impurities should correspond with lower conductivity. In at least one embodiment removal impurities proceed until the colloidal system has a conductivity of between 4000 μS/cm to 7000 μS/cm.
[0032] In at least one embodiment at least one of the impurities removed are one or more items that entered the colloid during a heel based formation process. These impurity items include but are not limited to alkali metal salts such as potassium or sodium based salts and acids or acid residues and acid derivatives. In a heel based process an initial composition, known as a “heel” is formed into which is added a source of active silica, usually in the form of silicic acid or polysilicic acid, over a specified time. The heel may be composed of water, any of a number of commercially available silicates or alkali water glasses, and an acid and/or a corresponding salt thereof in a prescribed ratio. A detailed example of a heel based formation process is:
[0033] (a) forming a heel, with said heel containing water, an alkali metal silicate Wherein the molar ratio of SiO 2 to Na 2 O or K 2 O is greater than about 1:1 and is less than about 15:1; an acid (and/or a corresponding salt thereof), wherein said heel has a pH of at least 10, wherein the alkali metal silicate and acid are initially present in a ratio by weight of at least 63:1, wherein the temperature of the heel is below 100 degrees F.;
[0034] (b) adding to the initial composition an aqueous silicic acid composition typically having a SiO 2 content in the range of from about 5.0 to about 7.2 percent by weight, while maintaining the temperature of the composition below 100 degrees F., wherein the aqueous silicic acid composition is added slowly and continuously until from about one half to about three-quarters of the silicic acid composition has been added to the initial. composition;
[0035] (c) increasing the temperature of the composition from below 100 degrees F. to between about 115 degrees F. and about 125 degrees F. in a time period of from about 10 to about 35 minutes, and maintaining the temperature until the addition of all the silicic acid composition is complete;
[0036] (d) optionally, maintaining the temperature of the composition below 125 degrees F. for about an hour; and
[0037] (e) discontinuing the heating and
[0038] (f) optionally removing water from the resulting composition until the solids content based on SiO 2 of the resulting aquasol is at least about 7.00 percent by weight.
[0039] Acids which may used in a heel based process can be any number of organic or mineral acids. Examples of such acids include, but are not limited to: mineral acids such as hydrochloric, phosphoric or sulfuric or such materials as carbon dioxide. Organic acids include but are not limited to: acetic acid, formic acid and propionic acid. Examples of suitable salts include: sodium sulfate, sodium acetate, potassium sulfate, potassium acetate, trisodium phosphate and sodium monohydrogen phosphate.
[0040] Once the heel is prepared, the temperature of the composition is reduced to 85 degrees F. or lower, typically to 80 degrees F., or lower, and usually in a range of from 60 to 85 degrees F. At this point, silicic acid or poly silicic acid is slowly added to the composition, for example over a total period of about 4 hours, Silicic acid suitable for the present invention can be prepared via known methods in the art, such as the cation exchange of dilute solutions of alkali water glasses. Typically, the dilute solutions contain from 3.0 to 9.0 percent by weight solids based on SiO 2 , typically from 5.0 to 7.2 percent by weight, and preferably from 6.0 to 6.8 percent by weight. Representative commercial preparations are outlined in U.S. Pat. Nos. 3,582,502 and 2,244,335. While the ratio by weight of the alkali metal silicate to acid can vary, typically the ratio is at least 63:1. The silicic acid or poly silicic acid is slowly and continuously added to the composition with stirring, until from about one-half to about three-quarters of the silicic acid or poly silicic acid has been added to the composition while maintaining the temperature of the composition below 85 degrees F., typically from about 60-85 degrees F. Thereafter, the temperature of the composition is slowly raised, for example over a period of from 10 to 35 minutes, to from 115-125 degrees F. and held in this temperature range until the addition of the remainder of the silicic acid or poly silicic acid to the composition is complete.
[0041] As described in U.S. Pat. No. 6,486,216 a heel based colloidal silica can be concentrated and remain stable until the final colloidal product contains from about 7.00 percent to about 16.8 percent by weight SiO 2 . If however the various compositions that were acquired during the heel process are removed in an amount such that the impurity-silonol reactivity decreases while the silanol-silanol reactivity does not increase, colloids with a higher weight % can be prepared.
[0042] In at least one embodiment at least one of the impurities removed are one or more items that entered the colloid during a resin based formation process. These impurity items include but are not limited to cationic resin exchange material, weak acids, and alkali metal based salts. In a resin based formation process a cationic ion exchange resin, preferably a weak acid cationic ion exchange resin, is used to initiate the reaction of an alkali metal silicate to produce the colloidal silica. The reaction is controlled by the rate of addition and the ratio of alkali metal silicate to ion exchange resin during the polymerization to produce the colloidal silica. Heat treatment of the colloidal silica product is optional.
[0043] A detailed example of a resin based formation process includes the steps of:
[0044] (a) charging a reaction vessel with a cationic ion exchange resin having at least 40 percent of its ion exchange capacity in the hydrogen form wherein the reaction vessel has means for separating the colloidal silica formed during the process from the ion exchange resin;
[0045] (b) charging the reaction vessel with an aqueous alkali metal silicate having a mole ratio of SiO 2 to alkali metal oxide in the range of from about 1:1 to about 15:1 and a pH of at least 10.0,
[0046] (c) stirring the contents of the reaction vessel until the pH of the contents of the vessel is in the range of from about 8.5 to about 11.0;
[0047] (d) adjusting the pH of the contents of the reaction vessel to above about 10.0, using an additional amount of the alkali metal silicate; and
[0048] (e) separating the resulting colloidal silica of the invention from the ion exchange resin while removing the colloidal silica from the reaction vessel.
[0049] A reaction may be controlled by the rate of addition (for example, from 0 to 30 minutes, typically less than 15 minutes) and the ratio of alkali metal silicate to ion exchange resin during the polymerization to produce the colloidal silica. The molar ratio of hydrogen ion in the cationic ion exchange resin to alkali metal ion in the alkali metal silicate ranges from 40 to 100 percent, preferably from 50 to 100 percent. The temperature during colloidal silica formation in this alternative embodiment of the invention generally ranges from 50 degrees F. to 100 degrees F., preferably from 70 degrees F. to 90 degrees F. Heat treatment of the colloidal silica product (i.e., post treatment) is optional in this embodiment of the process of the invention. The adjustment of pH in step (d) can be carried out either in the reaction vessel or after the resulting colloidal silica has been removed from the reaction vessel. This adjustment of pH typically is carried out within 10 minutes to 3 hours from when step (e) has been completed.
[0050] In at least one embodiment the separation step results in a solids % content of the colloid which is increases by up to 25% without any corresponding loss or impairment in stability, S-Value, and/or particle surface area. In at least one embodiment the increased solids colloid is used in a papermaking process without any loss in effectiveness. For example the increased solids colloid can be used in conjunction with polymeric flocculants and/or cationic starch with or without the addition of a coagulant as part of a retention and drainage program without any loss of effectiveness or unwanted side effect.
EXAMPLES
[0051] The foregoing may be better understood by reference to the following Examples, which are presented for purposes of illustration and are not intended to limit the scope of the invention:
[0052] A number of colloidal silica samples were produced according to a resin based formation process. Various properties of the samples were measured, S-Value, surface area, and solids % are proxys for predicting the sample's effectiveness in industrial applications. The samples were derived from commercially available colloidal silicas (POSITEK 8699 by Nalco Company, Naperville, Ill.) and were modified according to one of the following treatment protocols:
[0053] I) No modification
[0054] II) Cationic Resin added to reduce conductivity
[0055] III) Ultra-filtration applied
[0056] IV) Di-filtration applied
[0000] Properties of these samples are listed below,
[0000] TABLE I Sample Number (Indicates Surface Treatment Area S-Value Type) Solids % (m 2 /g) (%) pH 1-I 14.36 739.3 39.1 11.04 2-I 19.70 728.1 38.9 10.97 3-II 19.54 721.1 40.1 10.80 4-I 14.46 727.4 36.5 11.03 5-I 19.76 712.4 36.5 11.02 6-I 10.77 761.1 33.5 19.97 7-II 14.58 747.5 34.5 10.99 8-IV 19.76 716.3 34.4 11.02 9-III 19.75 732.5 33.5 10.98 10-I 19.75 716.3 33.5 10.98
The stabilities of these colloids were as follows:
[0000]
TABLE 2
Sample
Sample
Sample
Sample
Sample
Sample
10-I
9-III
8-IV
Elapsed
2-I
3-II
4-I
Vis-
Vis-
Vis-
Time
Viscosity
Viscosity
Viscosity
cosity
cosity
cosity
(Weeks)
(cps)
(cps)
(cps)
(cps)
(cps)
(cps)
0
9.5
9.5
12.4
26.9
33.2
19.7
1
17.3
11.9
19.3
256.0
47.2
21.7
2
135.0
17.6
29.1
>4000
80.3
26.7
3
>4000
31.6
69.5
Gel
289.0
36.6
4
>4000
72.6
301.5
Gel
>2000
81.4
[0057] The data shows that initial charge variability in colloids will lead to differing initial values and stability of colloid. It also shows that using a cationic resin may negate some of the charge based colloidal stability issues but does so at the expense of desirable properties in the colloid. Sample 8-IV however shows that when properly using difilitration, equilibrium can be reached in which the charge based effects on stability can be achieved without sacrificing desirable colloidal properties.
[0058] A number of other colloids were produced using the inventive method which illustrates the stability (via viscosity) of the colloids. These samples demonstrate that some removal of impurities does not significantly decrease colloidal stability by not significantly increasing the viscosity but that too much removal causes the viscosity to significantly increase because of greater silanol-silanol interactions.
[0059] Equipment used to prepare the high solids colloidal silica is comprised of a 60 gallon jacketed stainless steel reactor vessel, PCI ultrafiltration unit with PVDF membranes. Charge 254 lb. of a standard commercial silica, Nalco 8699, into the 60 gallon reactor, followed by 254 lb, of soft water (˜260 μS/cm conductivity). Mix reactor contents, heat the diluted solution to 100° F., then open the ultrafiltration loop valve, allowing the solution to recirculate through the ultrafiltration unit. Maintain pump outlet pressure at 100-110 psi throughout the entire process. As the silica solution concentrates, measure the flow rate, mass, and conductivity of ultrafiltration unit permeate to estimate silica solids.
[0060] Stop ultrafiltration when solution actives reach ˜15.0%, Charge an additional 128 lb. of soft water into the reactor, lowering silica concentration to ˜10.0%. Mix reactor contents, heat to 100° F., then recirculate through the ultrafiltration unit the same as in the previous paragraph, with the goal of concentrating the silica solution to ˜21.0% actives. Maintain pump outlet pressure at 100-110 psi. Collect silica solution aliquots at select times during the entire diafiltration process. Characterize samples in terms of pH, conductivity, specific gravity, Brookfield viscosity, and percent solids.
[0000]
TABLE 3
Specific
Brookfield
Specific
Gravity %
Viscosity
Microparticle
Solids %
Gravity
Solids
pH
(#1 @ 60)
1-I
14.49
1.0979
14.67
10.79
5.4
Initial
7.30
1.0474
7.74
n/a
n/a
Dilution
A
14.66
1.0980
14.69
10.67
5.5
B
9.63
1.0626
9.82
10.63
3.3
C
14.64
1.0976
14.63
10.59
5.6
D
16.78
1.1134
16.80
10.57
7.9
E
18.04
1.1229
18.10
10.56
10.0
F
19.17
1.1316
19.30
10.54
12.4
G
20.12
1.1387
20.27
10.54
15.6
H
21.18
1.1467
21.37
10.53
20.8
[0061] The same procedure was then performed for diafiltration with no changes in the first dilution-concentration step. Charge 253 lb, of soft water into the reactor for the second dilution, instead of 128 lb. in example 1, and stop ultrafiltration when solution actives reach ˜15.0%. Charge an additional 138 lb, of soft water into the reactor for a third dilution, lowering silica concentration to ˜10.0%, Mix reactor contents, heat to 100° F., then recirculate through the ultrafiltration unit, with the goal of concentrating the silica solution to ˜21.0% actives. Maintain pump outlet pressure at 100-110 psi.
[0062] Collect silica solution aliquots at select times during the entire diafiltration process. Characterize samples in terms of pH, conductivity, specific gravity, Brookfield viscosity, and percent solids.
[0000]
TABLE 4
Specific
Brookfield
Specific
Gravity %
Viscosity
Microparticle
Solids %
Gravity
Solids
pH
(#1 @ 60)
1-I
14.49
1.0979
14.67
10.79
5.4
Initial
7.19
1.0463
7.59
n/a
n/a
Dilution
A
14.49
1.0964
14.47
10.74
5.3
B
7.05
1.0453
7.45
10.66
2.9
C
14.63
1.0968
14.52
10.59
5.8
D
9.71
1.0633
9.92
10.56
3.6
E
15.21
1.1006
15.04
10.50
6.7
F
17.61
1.1183
17.47
10.46
10.0
G
19.55
1.1334
19.55
10.44
14.8
H
20.23
1.1386
20.26
10.43
17.5
I
21.16
1.1456
21.22
10.41
22.5
[0063] The same procedure was performed for diafiltration with no changes in the two dilution-concentration steps, except the substitution of deionized water (<1 μS/cm) for soft water.
[0000]
TABLE 5
Specific
Brookfield
Specific
Gravity %
Viscosity
Microparticle
Solids %
Gravity
Solids
pH
(#1 @ 60)
1-I
14.49
1.0979
14.67
10.79
5.4
Initial
7.32
1.0470
7.68
n/a
n/a
Dilution
A
14.60
1.0976
14.63
10.84
5.6
B
9.65
1.0625
9.81
10.81
3.6
C
14.65
1.0975
14.62
10.74
6.0
D
16.88
1.1138
16.85
10.72
8.3
E
18.16
1.1233
18.16
10.71
10.7
F
19.22
1.1313
19.26
10.70
12.9
G
20.20
1.1388
20.29
10.69
16.2
H
21.14
1.1459
21.26
10.68
20.7
[0064] While this invention may be embodied in many different forms, there are shown in the drawings and described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. All patents, patent applications, scientific papers, and any other referenced materials mentioned herein are incorporated by reference in their entirety. Furthermore, the invention encompasses any possible combination of some or all of the various embodiments described herein and incorporated herein.
[0065] Any ranges given either in absolute terms or in approximate terms are intended to encompass both, and any definitions used herein are intended to be clarifying and not limiting. All ranges and parameters disclosed herein are understood to encompass any and all subranges (including all fractional and whole values) subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, (e.g. 1 to 6.1), end ending with a maximum value of 10 or less, (e.g. 2.3 to 9.4, 3 to 8, 4 to 7), and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements,
[0066] The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
[0067] This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto. | The invention provides a method for improving the effectiveness of colloidal silica. The method involves removing enough charged impurities from the colloid to prevent the charged particles from causing the colloid to become a viscous gel. The method however also involves not removing too many charged particles so the silica material doesn't gel by cross-linking with itself. This method is quite effective because it recognizes that materials that have accumulated during the formation of the colloid do perform an important function, but they can perform better at a lower concentration. | 3 |
This is a continuation of application Ser. No. 671,187, filed Nov. 14, 1984, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to an underwater cleaning apparatus for cleaning and removing substances adherent to vessels or structures (hereinafter referred to as cleaning object) submerged in seas or lakes, etc.
Vessels and the like require cleaning either periodically or whenever a need arises to remove various living things such as seaweeds and shells or contaminants such as oil for the sake of appearance and proper performance. Divers were conventionally employed to manually remove them one by one using a scraper as one means to remove such substances. Such manual operation is, however, extremely inefficient, involving great amounts of time and labor especially for large ships.
Various cleaning apparatuses have been proposed such as shown in schematic views of FIGS. 1 and 2 to overcome above mentioned problems (for instance, Japanese Utility Model Application No. 32107/1978). An underwater cleaning apparatus 100 shown in FIGS. 1 and 2 comprises a main body 100A and cylindrical outer shells 101, 102 and 103 on both sides of the rear and at the center of the front of the main body 100A, respectively. Impellers 104 to 106 are concentrically provided inside the cylindrical outer shells 101 to 103, so that the bottom surface of the main body 100A is pressed against the cleaning object by the propulsion of the impellers 104 to 106 as they are driven to rotate. Three wheels 110 to 112 are provided at the bottom of the main body 100A, by steering the wheel 110 at the back end toward the direction of either left L or right R, the underwater cleaning apparatus 100 can be manipulated in any arbitrary direction. Cleaning brushes 107 to 109 are also provided at the bottom concentrically with the impellers 104 to 106 to remove substances adherent to the object. The cleaning brushes 107 to 109 are rotated as the impellers 104 to 106 are actuated so as to remove substances adherent to the object. The impeller 104 in the outer shell 101 and the cleaning brush 107 rotates in a direction opposite to the rotational direction of the corresponding impeller 105 in the outer shell 102 and the cleaning brush 108. The impeller 106 and the cleaning brush 109 in the outer shell 103 at the front rotate in the direction of either L2 or R2. For convenience, levers 114 are provided on the main body 100A for controlling and manipulating the cleaning operation as well as a railing 115 for operators to hold. On top of the outer shells 101 to 103, baskets 101A to 103A are attached to hold substances collected by cleaning operation.
With such as construction, the underwater cleaning device 100 is operated by manipulating the lever 114. Since its direction of advance is controlled by steering the wheel 110 on the rear side, the direction cannot be changed on the spot without turning it around in arc. When the wheel is steered, it becomes necessary to manipulate the lever 114 to restore its original position if the apparatus is to move straight ahead. Further, since there are an odd number (3 in this case) of impellers 104 to 106 with the cleaning brushes 107 to 109 connected thereto, the overall balance of the apparatus is difficult to be maintained despite of the efforts to maintain the balance by rotating the outer shells 101 and 102 at the back in opposite directions. This is because impellers 106 and the cleaning brush 109 in the outer shell 103 at the front must always rotate in the direction of either L2 or R2. With the conventional apparatus, the cleaning brushes 107 to 109 are fixed to the impellers 104 to 106, respectively. Although this poses no problem when cleaning a flat surface, cleaning of an irregular surface becomes difficult because the brushes per se are incapable of making vertical movement and may clash with the surface of the object depending on the position of the underwater cleaning apparatus 100 or cause themselves or the object surface to be damaged. There is provided no means to adjust the buoyancy or the posture of the main body 100A in the conventional cleaning apparatus 100. Thus, the buoyancy of the cleaning apparatus 100 may greatly vary depending on whether the water is fresh or brine, preventing smooth operations. The apparatus may become unbalanced depending on the direction or the posture of operation. It also poses problems in respect of energy consumption as it requires great force in manipulation. As the main body 100A is substantially circular in plan view, it was difficult to remove adherent substances from the corners of the object.
SUMMARY OF THE INVENTION
An object of this invention is to provide an underwater cleaning apparatus which can assure smooth and thorough cleaning of an underwater object.
Another object of this invention is to provide an underwater cleaning apparatus which is possible to change the direction thereof on the spot and to move straight ahead without manipulation of the lever.
Still another object of this invention is to provide an underwater cleaning apparatus which is possible to easily maintain the balanced posture and to control the buoyancy according to the surroundings.
According to this invention in one aspect thereof, for achieving objects described above, there is provided an underwater cleaning apparatus comprising a main body, impellers provided substantially at the center of said main body to press the same against the surface of a cleaning object by its rotation, and cleaning brushes provided on said main body at its bottom which are pressed against the object and are concentrical with said impellers to remove substances adherent to the object by rotating, said cleaning apparatus being characterized in that said main body is made movable on the object surface by the rotation and driving force of the impellers, a pair each of the impellers and the cleaning brushes are provided in parallel and at the normal angle with respect to the direction in which the apparatus moves forward and backward and the impellers and the brushes are driven by one driving source by connecting them by means of a universal joint.
According to this invention in another aspect thereof, there is provided an underwater cleaning apparatus with a buoyancy control means comprising a main body, impellers provided substantially at the center of said main body to press the same against the surface of a cleaning body by its rotation, and cleaning brushes provided on said main body at its bottom which are pressed against the cleaning object and are concentrical with said impellers to remove substances adherent to the object by rotating, said cleaning apparatus being characterized in that said main body is made movable on the object surface by the rotation and driving force of the impellers, cylindrical floats having a variable capacity are provided either in front of and at the back of or on both sides of the impellers so as to control the buoyancy of said main body of the cleaning apparatus under water.
Further, according to this invention in still another aspect thereof, there is provided an underwater cleaning apparatus with posture control means comprising a main body, impellers provided substantially at the center of said main body to press the same against the surface of a cleaning body by its rotation, and cleaning brushes provided on said main body at its bottom which are pressed against the cleaning object and are concentrical with said impellers to remove substances adherent to the object rotating, said cleaning apparatus being characterized in that said main body is made movable on the object surface by the rotation and the driving force of the impellers; and a circular fixing member which surrounds said impellers and which seals movable substance in its hollow wall so that the movable substance may move in the hollow wall in correspondence with the horizontal movement of the cleaning apparatus, is provided.
The nature, principle and utility of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a prespective view showing one embodiment of a conventional underwater cleaning apparatus;
FIG. 2 is a view to explain the functions thereof;
FIG. 3 is a perspective view showing one embodiment according to the present invention;
FIG. 4A is a plan view partly in section showing the structure of the embodiment;
FIG. 4B is a partial sectional view showing the structure of the embodiment from the side;
FIG. 4C is a partial view showing the structure of the embodiment;
FIG. 5 is a view partly in section showing the structure of the impellers and brushes in detail;
FIG. 6A is a front view showing the structure of a universal joint;
FIG. 6B is a side view thereof;
FIG. 7 is a view partly in section showing another embodiment of connecting means between the impellers and the brushes;
FIG. 8 is a schematic diagram showing the construction of the present invention regarding the buoyancy;
FIG. 9 and FIGS. 10A and 10B are views to explain the control means for the wheels, respectively;
FIG. 11A is a sectional view showing the structure of a float used in the present invention;
FIG. 11B is a side view thereof;
FIG. 12 is a functional view showing one embodiment of the posture control means according to the present invention;
FIG. 13 is a sectional view showing the structure of the posture control means; and
FIG. 14 is a view showing a state of the posture control means.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in more detail.
FIG. 3 and FIGS. 4A through 4C show the appearance and the structure of one embodiment according to the present invention. The underwater cleaning apparatus according to the present invention comprises a rectangular main body 1 which is substantially a square in plan view with an elliptic cavity 1A at the center of the main body 1, cylindrical dents 2 and 3 bored inside the cavity 1A, impellers 4 and 5 inside the dents 2 and 3 respectively, and cleaning brushes 6 and 7 respectively connected to the bottom of the impellers 4 and 5 by means of a universal joint 10. Motors 8 and 9 are connected to the impellers 4 and 5 at the top thereof to drive and rotate the same in opposite directions to each other. Inside the dents 2 and 3 is also provided an elevator mechanism 20 for moving a mounting member 21 vertically by means of an oil pressure cylinder, the mounting member 21 fixedly mounting the impellers 4 and 5. The elevator mechanism 20 is controlled by lever 63 (or by remote control) provided at the rear of the cleaning apparatus 1. The mounting member 21 is also mounted fixedly with the oil pressure motor 8 (or 9), at the bottom of which is connected the impeller 4 (or 5) as well as the brush 6 (or 7) via the universal joint 10. Thus, as the mounting member 21 is vertically moved by means of the elevator mechanism 20, the cleaning brushes 6 and 7 move freely within the range between the position I (upper limit) and the position II (lower limit) as indicated in FIG. 4B.
Floats 30 and 31 are provided in parallel on the main body 1 in front of and at the back of the dents 2 and 3, respectively, for controlling the buoyancy of the apparatus to maintain its balance. Above the floats 30 and 31 is provided a posture control means 40 which surrounds dents 2 and 3 in the form of a true circle with a hollow inside so that the posture control means 40 controls the posture of the main body 1 with less energy. Four wheels 51 to 54 are provided at the four corners of the bottom of the main body 1 for mobility. The wheels 51 and 52 on one side and the wheels 53 and 54 on the other side of the axis along the direction of the forward and backward movement of the apparatus are driven independently and serially by oil pressure motors 55 through 58. A railing 61 is provided along the outer periphery of the main body 1 for the operator to hold or for other convenience. Light lamps 62 are provided at the front and back of the bottom to facilitate the operation in dim places such as at the sea bottom or to prevent any hazards. A net basket may be attached to the top of the cavity 1A to collect the removed substances.
FIG. 5 shows the construction of the impellers 4 and 5 and the cleaning brushes 6 and 7 in detail together with the universal joint 10 which connects the above two members. When, for example, the impeller 4 is rotated in the direction M in the figure by means of the oil pressure motor 8, propulsion in the direction D can be obtained. The rotation of the impeller 4 is transmitted to the cleaning brush 6 via the universal joint 10. Because of the connection by the universal joint 10, the cleaning surface CS of the cleaning brush 6 can be slanted at any arbitrary angle to accommodate with the curvature of the object. A spring 11 is inserted between the impeller 4 and the cleaning brush 6 in a manner to surround the universal joint 10, so that the cleaning surface CS of the cleaning brush 6 can be maintained horizontal under normal condition. The oil pressure motor 8 is fixed to the mounting member 21 which is connected by means of a connecting strip 23 to the cylinder rod 22 of the elevator mechanism 20, the cylinder rod 22 being fixed to the mechanism at its bottom at the main body 1. The elevator mechanism 20 comprises a piston 26 and a cylinder 28 which houses the piston 26. In one section of the cylinder 28 partitioned by the piston 26, pressurized oil is flowed in or out via an injection pipe 25; in the other section, an injection pipe 25 is provided for the same purpose. By changing the amount of oil pressure in the two sections divided by the piston 26 via the injection pipes 24 and 25, the piston 26 will move vertically to thereby move the mounting member 21 via the cylinder rod 22 and the connecting strip 23 which are connected to the piston 26. FIGS. 6A and 6B show an embodiment of the structure of the universal joint 10. A fixing member 12 of the cleaning brush 6 has a dent which is in an orthogonal relation to the dent made in a transmission member 16 of the impeller 4, and between the members 12 and 16 is provided a connecting member 13. The connecting member 13 and the fixing member 12 are journalled by a pin 15, and the connecting member 13 and the transmission member 16 by a pin 14. In this manner, the rotational force from the transmission member 16 is directly transmitted to the cleaning brush 6, which, at the same time, is made capable of freely directing its cleaning surface CS at an arbitrary angle and direction. It should be noted that the structure of the universal joint 10 is not limited to the one shown in FIGS. 6A and 6B but any structure may be employed so long as the rotational force of the impeller 4 is directly transmitted to the object and the cleaning surface CS of the cleaning brush 6 which is connected to the impeller 4 is directed in correspondence with the contour of the object.
FIG. 7 shows another embodiment of the driving mechanism for the cleaning brushes 6 and 7. A gear mechanism 70 is interposed between the universal joint 10 and the impeller 4, so that the impeller 4 and the cleaning brush 6 connected therewith may rotate in the opposite directions. As the impeller 4 and the cleaning brush 6 rotate in the opposite directions to each other, the water flow in the dent 2 becomes even and smooth and at the same time removal and disposal of substances becomes more effective.
FIG. 8 is a schematic diagram of the structure of the apparatus according to the present invention to show the positional relation of the floats 30, 31 and the wheels 51 through 54. The floats 30 and 31 are supplied with pressurized air via an air supply pipe 32 which is connected to a control means provided on a ship and the like. The floats 30 and 31 are positioned point-symmetrically with respect to the cavity 1A in order to maintain the overall balance of the device. The structure and the operation of the floats 30 and 31 will be described later. The wheels 51 to 54 are provided at the four corners of the bottom of the main body 1. FIG. 9 shows the driving mechanism for the wheels 51 to 54. Oil pressure is introduced from an oil pressure conduit T1 in the direction P and discharged from an oil pressure conduit T3 in the direction Q via valve control circuits 50 and 59. The valve control circuits 50 and 59 are connected directly with one another by an oil pressure pipe T2 while oil pressure motors 55 to 57 are connected by oil pressure conduits T4 to T9, respectively.
With the structure as described above, the wheels 51 and 52 and the wheels 53 and 54 are respectively regarded as one unit each arranged in parallel in the direction of the forward and backward movement of the apparatus and they may be controlled to move in the same direction at the same speed. Each wheel can also be controlled independently of the other wheels. In other words, in the case where the wheels 51 and 52 are controlled to advance and the wheels 53 and 54 are controlled in the same direction as above, the valve control circuits 50 and 59 are switched, as indicated in FIG. 10A, so as to introduce oil pressure from the valve control circuit 50 into the oil pressure motors 56 and 58 by branching out the oil pressure into the oil pressure conduits T4 and T7. The oil pressure is further introduced to the oil pressure motors 55 and 57 via the conduits T5 and T8. The oil pressure from the motors 55 and 57 is then introduced to the valve control circuit 59 via the oil pressure conduits T7 and T9 to be discharged from the oil pressure conduit T3. In this case, the amount of oil pressure to be introduced to the oil pressure conduits T4 and T7 can be individually controlled by controlling the valve control circuit 50. Thus, the speed of the motors 55 and 56 and the motors 57 and 58 may be differentiated, thereby controlling the direction of the cleaning apparatus. When the cleaning apparatus is to be moved straight ahead, it goes without saying that the motors are run at the same speed. In the case where the cleaning apparatus is to be turned around at one spot, the wheels 51 and 52 on one side of the cleaning apparatus are driven forward while the wheels 53 and 54 on the other side are driven backward (refer to FIG. 10B). This is achieved by so controlling the valve control circuits 50 and 59. Flow of the oil pressure into the oil pressure conduits T1 to T9 is controlled as shown in the figure. The cleaning apparatus can thus be turned around at one spot without taking a great span of space. Likewise, the wheels 51 and 52 may be driven backwards while the other two wheels forward. The forward and backward movements can be controlled by the valve control of the valve control circuit 59.
FIGS. 11A and 11B show the structure of the float 30 (or 31), which comprises a cylinder 33, and a piston 34 inserted in the cylinder 33 and attached therewith via an O-ring. The inside of the cylinder 33 is partitioned into an air chamber 35 and a water chamber 36 by the piston 34. A liquid inlet/outlet pipe 37 is provided in the wall of the water chamber 36 so that liquid such as seawater may freely flow in and out. A spring 38 is mounted in the water chamber 36 of the cylinder 33 and energizes the piston 34 at all times in the direction M. The capacity of the air chamber 35 may be varied by controlling the amount of air supplied from the air supply pipe 32 to thereby control the buoyancy of the float 30. In other words, when the air is introduced into the air chamber 35 under pressure, the piston 34 is pushed in the direction N so that the liquid in the water chamber 36 is discharged from the liquid outlet pipe 37 to thereby increase the buoyancy of the float 30. On the other hand, when the air pressure from the pipe 32 is reduced, liquid will spontaneously flow into the water chamber 36 because of the pressing action of the spring 38 and of the pressure of the deep seawater. The piston 34 is pushed in the direction M and, as a consequence, the capacity of the air chamber 35 decreases to thereby reduce the buoyance of the float 30. Thus, the capacity of the air chamber 35 is made variable by changing the amount of air supplied from the pipe 32 and the buoyancy of the float 30 can be controlled at will. Since the floats of such a construction are positioned symmetrically on both sides of the cavity 1A, the buoyancy of the cleaning apparatus can be accurately controlled while maintaining the balance. It is noted that the number of floats is not restricted to two but may be increased an may also be positioned on both sides of the apparatus.
FIG. 12 shows the structure of the posture control means 40 according to the present invention. A circular fixing member 41 with a hollow inside is fixed to the periphery of the cavity 1A. The fixing member 41 in section is rectangular (refer to FIG. 13). Inside the member 41, there are provided a number of metal balls 42 such as used in the pin ball game. These metal balls 42 roll freely inside the hollow cavity of the circular fixing member 41. When the cleaning apparatus is at a level position, the metal balls 42 are substantially evenly distributed. When the cleaning apparatus is positioned inclined such as on a slope, the metal balls 42 will roll over to one side, as shown in FIG. 14, thus shifting the center of gravity of the cleaning apparatus. This saves energy and eliminates use of a great driving force to control the movement of the cleaning apparatus. The posture of the cleaning apparatus can thus be easily shifted at a speed with less power. The posture control of this type which helps reduction of the force required to drive the main body bears a great significance in a cleaning apparatus such as the present invention as it is manipulated and operated under water where there is almost no gravity. Although the metal balls 42 are employed in the embodiment, mercury may be sealed instead in the fixing member 41 if it can be tightly sealed therein. In the case where mercury is used, oil which has a small specific gravity may be used to cover the mercury layer so as to prevent leakage of mercury vapor.
The cleaning apparatus having the above construction is pressed against the cleaning object by propulsion generated by the rotation of the impellers 4 and 5 which are operated by the lever 63, and moves freely on the object as the wheels 51 to 54 are driven. At this stage, the cleaning brushes 6 and 7 are raised at the position I. When the cleaning apparatus reaches a position where substances to be cleaned are found, the elevator mechanism 20 is operated to lower the cleaning brushes 6 and 7 to be rotated for cleaning operation at the position II. The cleaning brushes 6 and 7 are made of metal strips or needles and are capable of removing shells and seaweeds adherent to the object by the pressing and rotating forces thereof. The buoyancy and the posture of the cleaning apparatus are also controlled at this stage by the floats 30 and 31 and the posture control means 40, respectively.
As has been described in the foregoing, the cleaning brushes 6 and 7 according to the present invention are vertically movable by means of the elevator mechanism 20. When the cleaning brushes are not in use, they are raised at the position I as shown in FIG. 4B so that they do not come in contact with the object surface while the wheels 51 to 54 are driven. When the cleaning apparatus reaches a position where cleaning is desired, the brushes 6 and 7 are lowered by means of the elevator mechanism 20 to the position II as shown in FIG. 4B, at which position they are rotated for cleaning operation. This assures thorough and accurate cleaning. As the cleaning brushes 6 and 7 are vertically movable, there is no risk of damaging either the object surface or the brushes themselves by clashing with the projected portions even when the cleaning apparatus moves on an uneven surface.
As has been described in the foregoing, the underwater cleaning apparatus according to the present invention is provided with an even number of impellers and brushes (in this case, 2) so that the apparatus does not lose its balance by the rotation of the impellers and the brushes. Provision of floats either in front of and at the rear of or on both sides of the axis along the direction of forward and backward movement enables accurate control of the buoyancy even if it may vary depending on the salt content of the seawater. As the posture control mechanism of the present invention comprises a hollow wall and moving member which may freely roll or flow inside the hollow wall, the underwater cleaning apparatus can be controlled with respect to its positions with less power because when the device is to be moved toward a slope, the moving member inside the hollow wall immediately follows suit. Moreover, there are provided four wheels in the apparatus that can be controlled independently in pairs with respect to the forward or backward movement. This eliminates steering of wheels and the apparatus can be turned around at one spot with great ease. Because the cleaning brushes are vertically movable, damages which may otherwise occur during driving of the apparatus can be prevented and accurate removal of substances is assured. As the main body of the apparatus is rectangular in plan view, it allows the tip of the brushes to reach even the small corners for thorough cleaning. | Vessels and the like require cleaning either periodically or whenever a need arises to remove various living things such as seaweeds and shells or contaminants such as oil for the sake of appearance and proper performance. Divers were conventionally employed to manually remove them one by one using a scraper as one means to remove such substances. Such manual operation is, however, extremely inefficient, involving great amounts of time and labor especially for large ships. According to the present invention, the main body of a cleaning apparatus is pressed against an underwater object to be cleaned by means of impellers which are provided substantially at the center of the main body and driven to rotate, whereby cleaning brushes which are provided at the bottom of the cleaning apparatus concentrically with the impellers are rotated to remove substances adherent to the object while the cleaning apparatus is manipulated to run on the object's surface. Two pairs of an impeller and a brush are provided in parallel at the normal angle to the direction of forward and backward movement of the cleaning apparatus. The impellers and the brushes are driven by the same driving source as they are connected to the impellers by means of a universal joint. | 1 |
BACKGROUND
The invention generally relates to fluid delivery systems used to infuse parenteral fluids to patients intravenously and more particularly, to a mounting linkage for mounting a pumping mechanism.
Physicians and other medical personnel apply fluid infusion therapy to treat various medical complications in patients. For safety reasons and in order to achieve optimal results, it is desirable to infuse parenteral fluid in accurate amounts as prescribed by the physician and in a controlled fashion.
Over the years, various devices and methods have been developed to improve the infusion of fluids in a controlled and more accurate fashion. One type of infusion device is a peristaltic pump that acts on a portion of the tube carrying fluid between the fluid reservoir and the patient. More specifically, a linear-type peristaltic pump sequentially occludes adjacent segments of flexible tubing in a wave-like fashion to create a moving zone of occlusion and force fluid through the tubing. Operation of such a pump typically involves the mechanical operation of a peristaltic pumping mechanism on a flexible tubing positioned between the pumping mechanism and a platen or rigid base and a drive mechanism for driving the pumping mechanism. The pumping mechanism typically comprises a series of pumping devices (fingers) that are driven by a series of drive cams that are mounted on a rotating cam shaft, the cam shaft being coupled to a drive mechanism such as a step-motor. The pumping devices are received in a guide device that confines the movement of the pumping devices to a linear movement against the tubing. The speed of the drive mechanism may be adjusted to achieve a desired volumetric flow rate.
A force limited type of peristaltic pump has a biasing means such as a spring for limiting the force exerted by the pumping devices on the tubing. The pumping devices of a linear peristaltic pump move the same amount in their reciprocal, linear pumping action. The spring permits relative motion between the tubing and the pumping devices so that the force the pumping devices are able to exert on the tubing is kept at a predetermined maximum, which is proportional to the spring force. In one configuration, the pumping mechanism is held in a fixed position and the tubing is placed between the mechanism and a rigid platen, the platen being biased by a spring or springs towards the pumping mechanism. The tubing is placed between the platen and the pumping mechanism. If the compressive force supplied by the moving pumping devices against the tubing exceeds a predetermined threshold established by the springs, the springs yield and allow the platen to be displaced in the direction of such compressive force ensuring that the compressive force remains at the predetermined constant.
The above spring-biased platen approach is not practical in the case where a pumping segment is used that has its own built in platen already coupled to a fluid conduit segment for receiving the pumping devices, and the segment is rigidly mounted in an external position on the pump. In such a case, the pumping devices may be biased towards the tubing so that they may move away from the tubing and platen if the force they exert should exceed the maximum.
However, an important consideration in the mounting of the peristaltic pumping devices, the platen, and the biasing means is keeping a predetermined orientation between the devices when they must move relative to each other to limit the force applied to the tubing. For example, the peristaltic fingers of a linear peristaltic pump are typically mounted in a perpendicular orientation to the tubing to be operated upon and the platen. The platen is typically parallel to the tubing. In the case where the spring-loaded platen must move to relieve the force applied by the fingers, it should do so while remaining parallel to the tubing and perpendicular to the fingers. Likewise in the case where the peristaltic fingers are spring-loaded and must retract from the tubing, they should do so while remaining perpendicular to that tubing so that the correct pumping action continues to occur.
A further consideration in the design of a force limited system is immunity to agents that may interfere with the proper functioning of the force limiting mechanism. In the case where parenteral or other fluids may enter the spaces between the peristaltic fingers or their guides, this fluid may bind the fingers together or to their guides and prevent them from properly moving through the guides. If the mechanism is constructed so that the mechanism can still function partially, it may lift off of the tubing and a free flow condition may result. Such a condition is not desirable. Consequently, it is desirable that the peristaltic pump include a mechanism that prevents unregulated free flow of parenteral fluid from being introduced to the patient.
Hence, those skilled in the art have recognized the need for a mounting mechanism or linkage for use with a peristaltic-type infusion pump that maintains a predetermined orientation between the pumping devices, the tubing and the platen during the times when relative motion occurs between them in force limiting and other operational situations. In addition, those skilled in the art have also recognized the need for a mounting linkage that also prevents free flow through the pumping segment conduit in the event that an outside agent interferes with the proper motion of the pumping devices against the conduit. The present invention fulfills these and other needs.
SUMMARY OF THE INVENTION
Briefly, and in general terms, the present invention is directed to a system for delivering fluid to a patient, the system including a linkage for mounting a pumping mechanism in a predetermined orientation to a fluid conduit and maintaining that orientation through relative movement between the pumping mechanism and the conduit. In a further aspect, the system is also for preventing free flow of fluid through the conduit in the event that the pumping mechanism becomes unable to continue in its pumping motion.
More particularly, the system for delivering fluid to a patient includes a rigid base mounted so as to position the fluid conduit between the rigid base and the pumping mechanism. The pumping mechanism has a plurality of movable pumping devices guided by a guide device to control the direction of movement of the pumping devices. The pumping mechanism further includes a drive means rigidly mounted to the guide device and operative on the pumping devices to move the pumping devices in the guide device through a predetermined range of motion.
The mounting linkage is configured to mount the pumping mechanism in a predetermined orientation relative to the rigid base and in relation to the fluid conduit so that the pumping devices move into and out of contact with the fluid conduit for moving fluid through the conduit. The mounting linkage allows movement of the pumping mechanism relative to the rigid base, but constrains such movement to the predetermined orientation.
In a more particular aspect of the invention, the mounting linkage has a plurality of links pivotally interconnected wherein one of such links, defined as a base link, is fixed in relationship to the rigid base and about which the pumping mechanism moves.
In a further aspect of the invention, the pumping mechanism forms one of the links to define a pumping mechanism link, the pumping mechanism link connected by at least one additional link to the base link.
In a particular aspect of the invention, the mounting linkage comprises a four-bar linkage, one of such links being the base link and another of such links being the pumping mechanism link.
In yet a further aspect of the invention, the four bar linkage mechanism is shaped as a parallelogram with opposing links having the same length and always being parallel to each other.
In a more particular aspect of the invention, the pumping devices are maintained perpendicular to the rigid base to define the predetermined orientation.
In one aspect of the invention, the system further comprises biasing means for urging the pumping mechanism toward the rigid base whereby the pumping devices are biased toward the rigid base into contact with the pumping conduit. The drive means is rigidly connected to the pumping devices such that if the pumping devices are stopped from moving, the drive means is also stopped from moving.
In one aspect of the invention, the biasing means comprises at least one tension spring attached to the device guides and the pump housing.
According to another aspect of the invention, the biasing means comprises a second tension spring attached to the device guides and the pump housing.
In a more detailed aspect of the invention, the pumping devices are slidably received in the guide device. The pumping devices are formed with a transverse slot at their proximal end for receiving the drive means which comprises a drive shaft having a plurality of cams, the cams being received in the lateral slots of the pumping devices. The drive means is rigidly coupled to the guide device so that if one or more of the pumping devices is unable to move, the drive means also cannot move.
Other features and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, which illustrate by way of example, the features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a fluid delivery system embodying the mounting linkage of the present invention;
FIG. 2 is a schematic side view of a pumping unit of the fluid delivery system showing the mounting linkage mounting a pumping mechanism in a predetermined orientation relative to a rigid base of a pumping segment;
FIG. 3 is a schematic side view of the pumping unit similar to that shown in FIG. 2, but illustrating the pumping mechanism in a raised position but still with the predetermined orientation relative to the rigid base of the pumping segment in accordance with aspects of the invention;
FIG. 4 is an enlarged perspective view of the pumping unit showing a four bar mounting linkage;
FIG. 5 is a top view of the pumping unit shown in FIG. 4;
FIG. 6 is a partial sectional side view of the pumping unit shown in FIG. 4;
FIG. 7 is a partial sectional end view of the pumping unit taken along line 7--7 of FIG. 6 and showing the spring loading of the mechanism towards the rigid base;
FIG. 8 is a perspective view of the upper link of the mounting linkage shown in FIG. 4; and
FIG. 9 is a perspective view of the lower link of the mounting linkage shown in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description, like reference numerals will be used to refer to like or corresponding elements in the different figures of the drawings. Referring now to the drawings and particularly to FIG. 1, there is shown a parenteral fluid delivery system including a mounting linkage in accordance with the principles of the present invention. The fluid delivery system may be a force limited linear peristaltic-type pump 10 and is shown for purposes of illustration.
As shown in FIG. 1, the peristaltic pump 10 has a pump housing 12 having a front panel 13 including controls and displays 14. As shown, the pump 10 is mounted on a vertical support pole 18. The pump includes a pumping unit, generally indicated at 16, that protrudes through the front panel. The pumping unit 16 is configured to mate with a detachable disposable pumping segment 20 (shown detached in FIG. 1). The pumping segment may be fixed in position against the face of the pumping unit by a plurality of clamp arms 23.
The pumping unit 16 operates on the pumping segment to pump fluid therethrough. More particularly, the pumping unit 16 has a pumping mechanism 42 (FIGS. 2 and 3) including a plurality of pumping devices 22, in this case peristaltic fingers, that sequentially occlude adjacent segments of a fluid conduit portion (not shown) of the pumping segment 20 in a wave-like motion to force fluid through the conduit.
In general, the pumping segment 20 has an inlet port 24 formed at the top end thereof and an outlet port 26 formed at the bottom end thereof, the ports in fluid communication with the fluid conduit of the pumping segment. The inlet port is connected to a length of inlet tubing 28, the opposite end of the inlet tubing in fluid communication with an elevated fluid reservoir (not shown) containing parenteral fluid. The outlet port is connected to a length of outlet tubing 30, the opposite end of the outlet tubing in fluid communication with an infusion cannula (not shown) inserted in a blood vessel of a patient for administering parenteral fluid intravenously.
The pumping segment 20 is generally elongated and rectangular in shape. Referring briefly to FIG. 6, the pumping segment includes a rigid platen or base 32 having a cover with an access aperture 34 formed along the longitudinal length thereof for receiving the peristaltic fingers. An elastomeric resilient membrane 36 is disposed along the length of the aperture and parallel with the rigid base, the volume between the rigid base and membrane defining the resilient fluid conduit 38.
Referring now to FIGS. 2 and 3, the pumping unit 16, shown in schematic form, includes a mounting linkage 40 for mounting the pumping mechanism 42 in a predetermined orientation relative to the rigid base 32 of the pumping segment 20 in accordance with the principles of the invention. The pumping unit has a base plate 43 including a centrally located longitudinal slot or aperture 45. The pumping mechanism 42 includes the plurality of pumping devices 22 received in a guide device 44, the plurality of pumping devices operatively connected to a step motor 46 through a cam shaft and cams (not shown) so that as the step motor rotates, the pumping devices move in a linear direction into and out of contact with the membrane 36. The step motor 46 is rigidly mounted to the guide device 44.
The mounting linkage 40 maintains the pumping devices 22 in a predetermined orientation relative to the rigid base 32 of the pumping segment. As shown in FIG. 2, the mounting linkage is configured to hold the pumping mechanism 42 so that the pumping devices 22 protrude through the longitudinal slot 45 of the pumping segment 20 and contact the membrane 36 forming a fluid conduit 38 with the rigid base 32. The fluid conduit 38 is shown in FIGS. 2 and 3 for purposes of clarity in illustration as a resilient, deformable tube placed between the rigid base 32 of the pumping segment 20 and the pumping devices 22 so that the pumping devices sequentially occlude the fluid conduit in a wave-like motion to pump fluid therethrough. The pumping segment 20 is rigidly secured relative to the base plate 43 of the pumping unit 16 by means of the clamp arms 23 (FIG. 1).
Because the pumping segment includes a rigid platen 32 that is held in rigid relation to the front of the pump, it cannot move in the event that the forces imparted on the conduit 38 exceed a limit. Thus, the pumping mechanism 42 is mounted so that it moves in relation to the rigid platen 32. When the forces against the conduit 38 reach the limit, the pumping mechanism 42 retracts into the pump to reduce those forces.
The term "link" is used to designate the arms of the mounting linkage 40. The links are connected together by joints. The mounting linkage comprises a four bar linkage designed to maintain the pumping mechanism 42 in a predetermined orientation relative to the rigid base of the pumping segment 20.
As shown, the mounting linkage 40 is in the form of a four-bar parallelogram linkage comprising a base link 48 (shown schematically by dashed lines located in a support bracket 64), a pumping mechanism link 50 (shown schematically by dashed lines located in the pumping mechanism 42 itself), and upper and lower links 52 and 54, respectively. The base link is mounted to the base plate 43 of the pumping unit 16 in a perpendicular relationship relative to the base plate. The base link has an upper and lower base link pivot joints 56 and 58 spaced apart a predetermined distance. The pumping mechanism link 50 has pumping mechanism upper and lower pivot joints 60 and 62 spaced apart the same predetermined distance as the base link pivot joints. The ends of the upper and lower link are pivotally connected to the respective upper pivot joints 56 and 60 and the lower pivot joints 58 and 62. The length between the pivotal connections of the upper and lower links are the same distance so that the interconnection of all of the links provides the parallelogram linkage.
In addition, a biasing means for biasing the pumping mechanism 42 toward the rigid base 32 of the pumping segment 20 is provided. In this case, the biasing means comprises a pair of tension springs, one of which 63 is shown. The spring 63 is connected between the pumping mechanism 42 and a spring mount 65, rigid in relation to the base plate 43. While the mounting linkage allows movement of the pumping mechanism 42 in relation to the pumping segment, the spring 63 urges the pumping mechanism 42 toward the pumping segment 20 to accomplish the pumping function. The spring force provides the force limit of the pumping devices on the conduit 38.
As illustrated in FIG. 3, the pumping mechanism 42 is in a retracted position relative to the base plate 43 and the rigid base 32 of the pumping segment 20 in opposition to the tension force of the spring 63. Although the retracted position shown is extreme in that the pumping fingers 22 are barely touching the conduit 38, this view is for clarity in understanding the operation of the mounting linkage 40. By virtue of the mounting linkage in accordance with aspects of the invention, the pumping fingers 22 remain perpendicular to the fluid conduit at all positions of the pumping mechanism 42. It should be noted that even when the pumping mechanism is in a retracted position as shown in FIG. 3, the mounting linkage 40 is still in the shape of a parallelogram with opposite sides remaining parallel. This configuration results in the pumping fingers 22 remaining perpendicular to the conduit 38 at all positions.
Although the predetermined orientation of the pumping fingers 22 in relation to the conduit 38 in FIGS. 2 and 3 is perpendicular, other orientations may be found to be desirable depending on the particular application. Other orientations may be established by changing the angle of the pumping unit 16 in the linkage so that the pumping fingers 22 are at an angle other than perpendicular to the fluid conduit 38, as will be apparent to those skilled in the art.
Referring now to FIGS. 4 through 7, the pumping unit 16 is described in more detail. With particular reference to FIG. 4, the pumping unit has a generally planar base plate 43, the lateral opposite sides of the base plate have upstanding structural support members 47 that provide structural rigidity to the pumping unit. Inwardly disposed from the respective lateral opposite sides of the rigid base 43 are a pair of longitudinally spaced apart upstanding spring support members 49 that carry the spring mount 65 therebetween for mounting a pair of tension springs 63 to the base plate (only one side shown). In addition, the rearward end of the base plate 43 is formed with two laterally spaced-apart brackets 64, the brackets defining the base link 48 shown in a dashed line drawn on the bracket. The bottom end of each of the brackets has an outwardly projecting pivot pin 67 (only one shown) aligned along the same transverse axis parallel to the base plate. The top end of each of the brackets includes a transverse pivot bore 69 (only one shown) aligned on the same central axis parallel to the axis of the pivot pins.
The base plate 43 and the brackets 64 are composed of a polymeric material, such as ABS, and are formed as one piece by an injection molding process or the like to provide a single unitary body. The ABS material is somewhat resilient so that the respective upper ends of the brackets 64 may be slightly bent during assembly, but return to their predisposed shape.
In the embodiment shown in FIGS. 4, the linkage 40 provides a parallelogram as shown in FIGS. 2 and 3, although the parallelogram in FIG. 4 is not a rectangle.
Referring to FIGS. 5 and 6, the pumping mechanism 42 of the pumping unit 16 is described in more detail. The pumping mechanism 42 includes a step motor 46 rigidly mounted to the guide device 44. The step motor 46 includes a rotatable output shaft 83 (FIG. 6) that is coupled to a cam shaft 86 of the pumping mechanism. The cam shaft has mounted on it a plurality of adjacent cams 88, the cam lobes being angularly offset from one another. Thus the drive means in this embodiment comprises a step motor, camshaft, and cams, all of which are fixedly mounted to the guide 44.
The plurality of pumping-devices 22 are housed in the guide device 44. The guide device generally has a top 66, bottom 68, and forward ends 70. The forward end includes a mounting surface 72 to which the step motor 46 is fixedly attached by screws or the like. As shown, a shock absorbing spacer 74 is disposed between the motor and the mounting surface of the guide device. Although the spacer allows some motor movement in relation to the guide device, this movement is very limited and is only to dampen vibration. The forward end 70 of the guide device 44 has an upper pair of outwardly projecting pivot pins 76, and a lower pair of outwardly projecting pivot pins 78.
More particularly as shown in FIG. 5, the top end 66 of the guide device 44 has an elongated aperture 82, the lateral opposite sides thereof having a plurality of vertically disposed guide slots 84, extending from the top end of the guide device downwardly through vertical guide slots (not shown) formed through a like aperture 85 (FIG. 7) in the bottom end 68 of the guide device. The plurality of guide slots slidably receive the pumping devices 22.
With particular reference now to FIG. 7, the top end 66 of the guide device 44 is generally rectangular including a back plate 80 that extends downwardly to meet the bottom end 68 of the guide device. The front edge of the top end 66 of the guide device has a small spring retaining aperture 87 for receiving the upper hook of one of the tension springs 63. The lateral opposite top back edge of the guide block has a spring retaining loop 89 for mounting the upper hook of the other spring 63 thereon.
The guide device 44 is composed of a polymeric material, such as a rigid polyurethane, for example Isoplast made by Dow Chemical, and is formed as one piece by an injection molding process or the like to provide a single unitary body.
As shown in FIG. 7, each of the plurality of pumping devices 22 are generally elongated having a top surface 90 and bottom 92 end. The top end of each of the pumping devices has a transverse slot 94 having a generally semicircular end surface 96. The cams of the cam shaft are received in the slots of the devices in close tolerance but are free to rotate therein. Because the cam shaft is fixed relative to the guide device 44, as the cam shaft rotates, the pumping devices follow the cams sliding in the guide slots 84 (FIG. 5) in a linear reciprocating fashion. The bottom end of each of the pumping devices has a downwardly projecting finger 98 that contacts the fluid conduit for causing fluid movement through the conduit.
As described above, the pumping mechanism 42 of the pumping unit 16 is mounted by the mounting linkage 40 to the base plate 43. The components of the upper 51 and lower 54 links of the mounting linkage will be described hereinafter.
With particular reference to FIG. 8, the upper link 52 of the mounting linkage is described in detail. Its installed position can be seen by reference to FIGS. 4, 5, and 6. The upper link has two elongated arms (links) 100, each having a forward 102 and rearward 104 end. The rearward ends of the respective arms have a slight inward transition 106. The arms are laterally spaced apart and joined together by a pair of cross members 108 at the respective rear ends thereof. In addition, the cross members 108 hold the arms in a parallel relationship to each other. The cross members are constructed having a cross section in the form of a cross.
The respective forward ends 102 of the link 100 have an enlarged head 110 split along a vertical plane taken along the center line of each respective arm to define respective top 112 and bottom 114 ends. The bottom ends 114 of the enlarged heads 110 are offset outwardly with respect to the top ends 112 of the enlarged heads. A rear fillet 116 is formed between the offset transition between the top and bottom ends. The forward extremities of the top and bottom ends are fixed together.
The respective enlarged heads 110 of the arms each include a transverse pivot bore 118 aligned along a central axis perpendicular to the arms. The enlarged heads each have a protrusion 120 and 122 respectively that assists in properly retaining the upper link to the guide device when assembled. The guide includes retainers 121 and 123 to engage the protrusions on the arms when assembled, so that the arms may rotate but will not come off the pins. To assemble the arms on the pins, the arms are rotated so that they can be slid on the pins and are then rotated into the correct operational position.
The respective rearward ends 104 of the arms each includes an outwardly projecting, generally cylindrical, pivot pin 124 aligned about a central axis perpendicular to the arms. In addition, the respective upper link arms have a plurality of inwardly and rearwardly projecting wiring clips 126 that retain wires therein when the pump unit is fully assembled.
The upper link 52 is composed of a polymeric material, such as ABS, and is formed as one piece by an injection molding process or the like to provide a single unitary body. The ABS material is somewhat resilient so that the forward ends 102 of the arms 100 may be slightly bent outwardly during assembly, but return to their predisposed shape.
With particular reference to FIG. 9, the lower link 54 of the mounting linkage is described in detail. Its installed position can be seen by reference to FIGS. 4 and 5. The lower link has two elongated arms or links 128 each having forward 130 and rearward 132 ends. The rearward ends of the respective arms 128 have a slight outward transition 134. The arms are spaced laterally apart and are joined at their respective rearward ends by a bridge member, generally indicated at 136. In addition, the bridge member holds the arms in a parallel relationship to each other. Each of the arms is joined to the bridge member by a pair of longitudinally spaced apart upstanding members 138, the respective top ends thereof inwardly turned to join respective longitudinal brackets 140, the respective rear ends thereof joined by a cross bar 142 of the bridge member. The cross bar has a forward projecting hook member 144 that is used to support an electrical connector (not shown in the drawings). The respective forward ends 130 of the arms 128 are split along a vertical plane to define respective top 146 and bottom 148 ends. The bottom ends 148 are offset outwardly with respect to the top ends 146. The forward extremities of the top and bottom ends are fixed together. The respective forward ends 130 of the arms include a transverse pivot bore 150 aligned along a central axis perpendicular to the arms 128. The respective rearward ends 132 of the arms 128 are split along a vertical plane to define respective rearward top 152 and bottom 154 ends. The rearward bottom ends 154 are offset outwardly with respect to the rearward top ends 152. The rearward extremities of the rearward top and bottom ends are fixed together in the molding process. The respective rearward ends of the arms each include an transverse pivot pin bore 156 aligned along the same central axis perpendicular to the arms. The raised configuration of the bridge member allows for sufficient clearance of other pump unit components when assembled, those other components not shown in the figures.
The lower link 54 is composed of a polymeric material, such as ABS, and is formed as one piece by an injection molding process or the like to provide a single unitary body. The ABS material is somewhat resilient so that the respective forward and rearward ends 130 and 132 of the lower link arms 128 may be slightly bent during assembly, but return to their predisposed shape.
Returning to FIG. 4 as well as referring also to FIGS. 8 and 9, the upper 52 and lower 54 links are shown in their assembled state. During assembly, the forward ends 130 of the lower link are slightly bent outwardly so that the lower pair of outwardly projecting pivot pins 78 of the guide block 44 are slidably received in the forward pivot bores 150 of the lower link. Likewise, the rearward ends 132 of the lower link are slightly bent outwardly so that the lower pair of outwardly projecting base link pivot pins 67 of the upstanding members 64 are slidably received in the rear pivot bores 156 of the lower link. During assembly, the forward ends 102 of the upper link 52 link are slightly bent outwardly so that the upper pair of outwardly projecting pivot pins 76 of the guide block 44 are slidably received in the forward pivot bores 118 of the upper link. The upper ends of the brackets 64 of the base link are slightly bent outwardly so that the pair of outwardly projecting upper link pivot pins 124 are slidably received in the base link pivot bores 69.
In general, when assembled, the pivotal connection between the forward end pivot bores 188 of upper link 52 and the upper projecting pivot pins 76 of the guide device 44 define the upper pumping mechanism pivot joint 60. The pivotal connection between the rearward end pivot pins 124 of the upper link and the pivot bores 69 of the base link upstanding members 64 define the base link upper pivot joint 56. The pivotal connection between the lower pivot pins 78 of the guide device and the forward end pivot bores 150 of the lower link 54 define the lower pumping mechanism pivot joint 62. The pivotal connection between the lower projection pivot pins 67 of the brackets 64 and the rearward end pivot bores 156 of lower link 54 define the lower base link pivot joint 58.
As the pumping mechanism 42 is raised relative to the base plate, the upper and lower links 52 and 54 pivot angularly about the base link pivot joints 56 and 58. The lengths of the upper and lower links 52 and 54 have been selected to be generally much longer than the length of the base link 48 and pumping mechanism link 50. Thus, as the pumping mechanism is raised, the pumping mechanism follows an arc of generally a large radius. Therefore, the longitudinal tolerances between the pumping mechanism and stationary components of the pumping unit 16 may be tighter without the concern of contact. In addition, any friction introduced at the pivot joints is minimized.
In operation, the motor is actuated to rotate the cam shaft, the cams 88 thereof driving the pumping devices 22 in a linear reciprocal manner so that the fingers 98 advance and occlude adjacent segments of the fluid conduit 38. As each finger retracts from the fluid conduit, the resiliency of the conduit and the fluid pressure therein cause the previously occluded segment of the conduit to open and allow fluid flow therethrough. The interaction and timing of the sequential cams and pumping devices cause the pumping devices to move in a wave-like peristaltic fashion.
The mounting linkage 40 of the invention assures that the guide device 44 of the pumping mechanism constrain the pumping devices in a predetermined orientation which in this embodiment is perpendicular to the rigid base.
If excessive forces are applied by a pumping device 22 on the conduit 38 against the rigid base 32, the counter force overcomes the biasing force of the springs 63 and urges the pumping devices and pumping mechanism away from the rigid base. As the pumping mechanism is urged away, the mounting linkage 40 retains the predetermined orientation of the pumping devices against the fluid conduit and rigid base so that the pumping fingers remain in their desired orientation to the fluid conduit.
In the case where parenteral fluid or other foreign agents seep into the pumping mechanism 42 and coat the surfaces between the pumping fingers 22 and the guide slots 84 of the guide device 44, such fluids may cause one or more of the pumping fingers 22 to stick to the guide device 44 and interfere with or prohibit movement of that finger. As discussed above, it is desirable in such a case that at least one of the pumping fingers continue to occlude the conduit until this "stuck" condition can be discovered and remedied. The pumping mechanism should not "back off" the conduit when one finger is stuck in a guide.
The tolerances between the transverse slots 94 of the pumping devices 22 and the cams 88 of the cam shaft 86 are such that if even one of the pumping fingers is bound, the interaction of the cam within the slot 94 prohibits the cam shaft from rotating. This effectively stalls the motor and a lack of rotation will be sensed by a rotation sensor. The pumping operation will be terminated and an alarm provided.
The drive means shown in the figures comprises a cam shaft, cams, and motor rigidly mounted to the guide device 44. However, other arrangements are possible. For example, the motor may be located separately and a flexible drive shaft coupled to the cam shaft. In this case, the drive means rigidly mounted to the guide would be the cam shaft with cams and this arrangement would likewise prevent the fingers from backing off the conduit if sticking were to occur.
While particular forms of the invention have been illustrated and described, it will be apparent that various modifications can be made to the present invention without departing from the spirit and the scope thereof. | A fluid delivery system in which the pressure platen for a fluid conduit is fixedly mounted to the pump and the pumping mechanism is movable in relation to the platen to control the force exerted on the conduit. A mounting system comprising a four-bar linkage retains the movable pumping mechanism in a predetermined orientation to the conduit through the mechanism's range of movement. The pumping mechanism is spring loaded towards the conduit. The peristaltic fingers of the pump mechanism are located in guides with the drive means for those fingers rigidly mounted to that guide. Should the movements of one or more fingers through the respective guide be prevented, the drive means will be stopped from movement and the pumping mechanism will stall rather than back off and allow free flow. | 5 |
CLAIM OF PRIORITY BASED ON CO-PENDING PROVISIONAL APPLICATION
The present application is related to co-pending Provisional patent application Ser. No. 60/067,036 of Ruth A. Hendrickson and Peter F. Van Der Meulen, filed Dec. 1, 1997, entitled “APPARATUS AND METHOD ° FOR TRANSPORTING SUBSTRATES”, and based on which priority is herewith claimed under 35 U.S.C. 119(e) and the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to transporting substrates and, more particularly, to moving substrates into and out of areas with limited individual holding areas.
2. Prior Art
Substrate processing apparatus, commonly referred to as cluster tools, are known that include a module for supplying substrates from the exterior into a main processing section or chamber from which they are transferred into substrate processing modules communicating with the main section. The main chamber may be maintained in a vacuum and has a substrate transport for moving substrates among the processing modules, which transport may be of the type of transfer device described in PCT patent publication No. WO 94/23911. The processing modules may be of various forms familiar to the art. The substrate supply module is connected to a front end of the main section and typically has a frame, a substrate transport, and means for holding two substrate cassettes. The front end of the main section has two load locks that function as compartments for transporting the substrates between the vacuum chamber and the supply module 16 , i.e., between a vacuum environment and an atmospheric pressure environment. An external or atmospheric robot transports the substrates from the cassettes to the load locks, and an internal or vacuum chamber robot transports the substrates from the load locks to the processing modules. When the substrate processing is finished, the vacuum chamber robot transports the substrates from the processing modules back to the load locks and the atmospheric robot transports the substrates from the load locks back to the cassettes. Typically, the load locks are indexing load locks which have numerous substrate support shelves and an elevator mechanism to move the shelves up and down. The shelves in the load locks may be as many as 30, depending upon the corresponding number of substrates held in a single cassette. The external robot loads a full cassette of substrates into each load lock. The internal robot loads and unloads the substrates between the load locks and the processing modules and then returns the processed substrates back to their cassettes. In the prior art apparatus, a computer controller is programmed to move the vacuum robots such that a substrate moved from a first location, such as a shelf in one of the the load locks, will be returned to the same location after being transported to a second location. Recently, substrate processing apparatus are being manufactured to process newer larger substrates, such as 300 mm diameter semiconductor wafers or flat panel display substrates which could be as large as a square meter. Indexing load locks for such large substrates can hold a large quantity of substrates and have the advantage of providing very good substrate throughput. Large size substrates must also be relatively slowly exposed to environmental change in the load locks in order to prevent undesired effects such as vapor condensation on the substrates. Indexing load locks are again of advantage as they can effectively compensate or the longer load lock environment change time to retain good substrate throughput. However, indexing load locks are very expensive, and thus a problem is presented regarding how to maintain good substrate throughput, but nonetheless reduce the costs associated with large substrate indexing load locks.
3. Object
It is therefore an object of the present invention to provide a substrate processing apparatus which can achieve a comparable substrate throughput to that of an apparatus with large substrate indexing load locks while being of considerably lower cost.
SUMMARY OF THE INVENTION
The present invention embodies a method and apparatus for substrate processing at lower cost than existing systems that use large dimension or indexing load locks, by implementing an arrangement using load locks of smaller dimensions or of a non-indexing type, along with a substrate loading and unloading technique that maintains the fast throughput while reducing the size and cost of the load lock apparatus required. In accordance with the invention, a processed substrate is returned by the internal robot from one of the processing modules to the shelf or slot in the load lock from which the last substrate was removed for processing by the robot, rather than being returned to the original source shelf or slot from which it was removed for processing, as in the prior art. Also venting for a first one of the load locks can start as soon as the second load lock becomes the substrate source for the internal robot rather than waiting until the first load lock has been refilled with processed substrates. By virtue of these improved operations, small dimension load locks, whether of the indexing or non-indexing type, can be used in place of more expensive large dimension indexing type load locks while maintaining comparable substrate throughputs.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and other features of the present invention are explained in the following description, taken in connection with the accompanying drawings, wherein:
FIG. 1 is a schematic top plan view of a prior art substrate processing apparatus or cluster tool;
FIG. 2 is a schematic top plan view of a substrate processing apparatus comprising features of the present invention;
FIG. 3 is a partial schematic side view of one of the load lock areas of the apparatus shown in FIG. 2;
FIG. 3A is a partial schematic side view of the load lock area and substrate supply section of an alternate embodiment;
FIG. 3B is a partial schematic side view of the load lock area and substrate supply section of another alternate embodiment;
FIG. 4 is a schematic view of general components which the present invention can be used with;
FIG. 5 is a schematic top plan view of another alternate embodiment of the invention; and
FIG. 6 is a plot illustrating a comparison of the throughputs (wafers/hr.) achievable with the system of the invention versus that achievable with the prior art systems wherein the substrates are returned to the same slots from which they are picked up.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a schematic top plan view of a prior art substrate processing apparatus 10 or, as commonly referred to, a cluster tool. The apparatus 10 includes a main section 12 , substrate processing modules 14 and a substrate supply module 16 . The main section 12 has a substrate transport 18 for moving substrates among the modules 14 , 16 . The substrate transport 18 is substantially the same as the transfer device described in PCT patent publication No. WO 94/23911 which is hereby incorporated by reference in its entirety. However, any suitable type of transport could be used. The chamber 30 formed by the main section 12 is preferably maintained in a vacuum. The substrate supply module 16 is connected to a front end of the main section 12 . The supply module 16 has a frame 20 , a substrate transport 22 , and means for holding two substrate cassettes 24 , 25 . However, in alternate embodiments, any suitable type of substrate supply module could be provided. The substrate processing modules 14 are well known in the art and, therefore, will not be described further.
The front end of the main section 12 has two load locks 26 , 28 . The load locks function as compartments for transporting the substrates between the vacuum chamber 30 and the supply module 16 ; namely, between a vacuum environment and an atmospheric pressure environment. The atmospheric robot 22 transports the substrates from the cassettes 24 , 25 to the load locks 26 , 28 . The vacuum chamber robot 18 transports the substrates from the load locks 26 , 28 to the processing modules 14 . Similarly, when the substrates are finished being processed, the vacuum chamber robot 18 transports the substrates from the modules 14 to the load locks 26 , 28 and, the atmospheric robot 22 transports the substrates from the load locks 26 , 28 back to the cassettes 24 , 25 .
Typically, the load locks 26 , 28 are indexing load locks. Indexing load locks have numerous substrate support shelves and an elevator mechanism to move the shelves up and down. The shelves in the load locks could be as many as 13 , 25 , or 30 , preferably corresponding to the number of substrates held in a single cassette 24 , 25 . The atmospheric robot 22 loads a full cassette of substrates into each load lock. The vacuum chamber robot 18 loads and unloads the substrate between the load locks 26 , 28 and the modules 14 . The atmospheric robot 22 then returns the processed substrates back to their cassettes 24 , 25 . In the prior art, the computer controller 11 was programmed to move the robots 18 , 22 such that a substrate moved from a first location, such as a shelf in one of the cassette 24 , 25 or a shelf in one of the load locks 26 , 28 , would be returned to the same location after being transported to a second location.
Recently, substrate processing apparatus are being manufactured for newer larger substrates, such as 300 mm diameter semiconductor wafers and flat panel display substrates which could be as large as 2 feet square. Indexing load locks for such large substrates are very expensive. However, indexing load locks have the advantage of providing very good substrate throughput. Large size substrates must also be relatively slowly exposed to environmental change in the load locks in order to prevent undesired effects on the large size substrates, such as vapor condensation on the substrates. Indexing load locks, which can hold a large quantity of substrates can effectively compensate for the longer load lock environment change time to retain a good substrate throughput. Thus, a problem existed regarding how to maintain good substrate throughput, but nonetheless reduce the costs associated with large substrate indexing load locks.
Referring now to FIG. 2, a schematic top view of a substrate processing apparatus 50 incorporating features of the present invention is shown. Although the present invention will be described with reference to the single embodiment shown in the drawings, it should be understood that the present invention can be embodied in many alternate forms of embodiments. In addition, any suitable size, shape or type of elements or materials could be used. The apparatus 50 includes a main section 52 , substrate processing modules 54 , a substrate supply section 56 and load locks 58 connecting the main section 52 to the supply section 56 . The apparatus 50 also includes a computer controller 62 . In the embodiment shown, the apparatus 50 has three of the substrate processing modules 54 ; separately numbered P 1 , P 2 , P 3 . The apparatus 50 also has two of the load locks 58 ; separately labeled LA and LB. The main section 52 is preferably maintained in a vacuum or inert gas environment. The main section robot 60 has two end effectors 64 for individually supporting two separate substrates thereon. The main section robot 60 can move substrates between or among the various processing modules P 1 , P 2 , P 3 and load locks LA, LB. Preferably, the main section robot 60 is also adapted to vertically move the end effectors 64 up and down by moving the movable arm assembly 61 up and down. Doors 66 are provided between the main section 52 and the substrate processing modules 54 and load locks 58 .
The substrate supply section 56 includes a frame 68 , an atmospheric substrate transport mechanism 70 , and substrate cassette holders 72 . The transport mechanism 70 includes a car 74 movably mounted on rails of the frame 68 for linear movement on the rails as indicated by arrow X. The transport mechanism 70 also includes a robot 76 mounted to the car 74 . Referring also to FIG. 3, the atmospheric robot 76 has a drive system 78 , a movable arm assembly 80 connected to the drive system 78 , and an end effector 82 attached to the end of the movable arm assembly 80 . In the embodiment shown, the movable arm assembly is a scara arm assembly. In the embodiment shown, the end effector is adapted to individually move only one substrate at a time. However, in alternate embodiments, the end effector could be sized and shaped to move multiple substrates at the same time. In other alternate embodiments, any suitable atmospheric substrate transport mechanism could be provided. In the embodiment shown the drive system 78 is adapted to vertically move the movable arm assembly 80 and the end effector 82 as indicated by arrow Z 1 . The substrate cassette holders 72 are adapted to vertically move the cassettes 73 relative to the frame 68 as indicated by arrow Z 2 .
The load locks 58 are non-indexing load locks. In other words, the load locks do not have an elevator mechanism to vertically move substrates in the load locks up and down. The load locks each have four stationary substrate support shelves 84 . In alternate embodiments any suitable number of support shelves in the load locks could be provided, including only one shelf. However, with the non-indexing load locks, the number of shelves is generally limited to their relative spacing and the amount of vertical movement Z 1 , and Z 3 available to the two robots 76 , 60 . Doors 86 are provided at the atmospheric section side of the load locks. By providing the load locks 58 as a non-indexing type, a significant cost saving is obtained. For applications where the locks separate a vacuum environment from an atmospheric environment, the equalization cycle whereby the load lock is vented to atmospheric pressure or pumped to the required vacuum pressure must be done slowly to avoid transporting particles onto the substrate surfaces from turbulent gas flow or moisture condensation. For controlled atmospheric environments, the purge rate flow must be slow enough to avoid turbulence. For thermal equilibration, larger size substrates generally need to be exposed to environmental changes at a slower rate than smaller size substrates. Because the number of substrates which a non-indexing type load lock holds is significantly less than the number of substrates which an indexing type load lock can hold, substrate throughput would be expected to be significantly less when using the non-indexing type load locks. However, to overcome this problem, the present invention uses a new method to load substrates into the load locks 58 and unload substrates from the load locks.
As noted above, the apparatus 50 has a controller 62 . The controller 62 preferably comprises a computer. The controller 62 is operably connected to the two robots 60 , 76 , the doors 66 , 86 , the transport mechanism 70 , the movable substrate cassette holders 72 , and the processing modules 54 to control their functions. A unique feature of the present invention is that a processed substrate is returned by the robot 60 from one of the processing modules 54 to the shelf or slot 84 of the last substrate removed from the load lock by the robot 60 rather than to the processed substrate's original source shelf or slot 84 .
Another unique feature is that venting for a first one of the load locks can start as soon as the second load lock becomes the substrate source for the robot 60 rather than waiting until the first load lock has been refilled with processed substrates.
Referring also to FIGS. 3A and 3B, two alternate embodiments of the substrate supply section are shown connected to the load lock 58 . In FIG. 3A, the supply section 156 has the transport mechanism 170 with robot 176 . The cassette 124 is stationarily, but removably mounted to the frame 168 . The cassette 124 could be an open 13 or 25 wafer cassette. The robot 176 can vertically move its end effector 182 as indicated by arrow Z 2 to load and unload substrates between the cassette 124 and the load lock 58 . In FIG. 3B the supply section 256 has the same transport mechanism 170 with robot 176 . The cassette 224 is a Front Opening Universal Pod (FOUP), such as an Infab 13 or 25 wafer capsil which is stationarily, but removably mounted to the frame 268 . The frame 268 includes a movable door 267 that can be moved up and down when the wafer capsil 224 is changed.
FIG. 4 shows one of the most basic adaptations for the present invention. The first environment 300 and the second environment 302 could be two transport chambers, such as the main section 12 shown in FIG. 1, or one of the main sections 12 and an atmospheric section. The pass-through chambers 304 , 306 have one or more positions for holding material. Each pass-through chamber has two doors 308 , 310 that serve to isolate the pass-through chamber from the two environments. For example, one door might open to a standard semiconductor clean room; the other might open to a semiconductor vacuum transport chamber. Because the pass-through chamber connects the two different environments, the environment in the pass-through chamber must change to match the environment in the neighboring chamber before the isolation door opens. Consequently, the pass-through chamber is often called a pass-through lock or load lock.
A certain period of time must pass to equalize the environment in the pass-through chamber to the neighboring environment before the isolation door can be opened. The amount of material that can move through the pass-through chamber in a given time period is called “throughput”. To maximize throughput, the pass-through chambers are used in an alternating mode; one pass-through chamber will be receiving or sending material while the other pass-through chamber is equalizing. If the equalization time is short enough, one pass-through chamber may finish equalizing before the other finishes accepting or sending material. In that case, the equalization activity is “in the background”, and therefore does not inhibit throughput.
Typically, material handling robots move the material from one environment, through the pass-through chamber, and into the second environment. One material handling robot moves wafers from the first environment into the pass-through chamber; a second robot moves wafers from the pass-through chamber into a second environment. In practice, both the second and the first environments may have more than one handling robot.
FIG. 5 shows another alternate of the present invention. The main section 400 has more than three processing modules 402 attached to it. The main section 400 also has a substrate aligner 404 and a substrate cooler 406 located in paths to the load locks 58 . The substrate supply section 408 also includes a substrate buffer 410 between two cassettes. The present invention could be used with any suitable type of substrate processing apparatus.
The material moved includes, but is not limited to, wafers, substrates, and glass panels. The controlled environment includes, but is not limited to, vacuum (significantly less than atmospheric pressure), near atmospheric pressure but with controlled gas constituents, or any pressure with controlled temperature. The movement of the robot and the material is under the control of “scheduling” software. The presently described method pertains to the scheduling algorithm for this material movement.
In order to optimize the total tool throughput, using a substrate processing apparatus or cluster tool in accordance with the present invention, e.g., as shown in FIG. 2, the following exemplary scheduling algorithm may be followed for scheduling through two alternating pass through locks LA and LB. The preferred steps are set forth for a single-pan i.e., single holder or end effector, robot and a dual-pan robot.
EXAMPLES
Assume
Key
Two 4 slot pass through
LAn
Lock A, shelf n
locks
3 parallel PMs
LBn
Lock B, shelf n
10 substrates in cassette
Pn
Process Module n
Batch of 1 cassette to be
w1
substrate 1
processed
pk
pick up
pl
place
phm
pump, home, map
F1 cycle
vent, empty
and refill, pump,
home, map
EXAMPLE 1
Single-pan Robot
pl w1 to LA1
(Atmospheric robot 76 fills the locks)
pl w2 to LA2
pl w3 to LA3
pl w4 to LA4 ---------->
start LA phm
pl w5 to LB1
pl w6 to LB2
pl w7 to LB3
pl w8 to LB4 ---------->
start LB phm
pk w1 LA1
(fill cluster pipeline)
pl w1 P1
pk w2 LA2
pl w2 P2
pk w3 LA3
pl w3 P3
(pipeline full)
wait for P1 to finish
pk w1 P1
pl w1 LA3
(same slot as the most recent input
substrate came from) Note that in an indexing
lock, this means no index is required between
pick and place at the load lock.
pk w4 LA4
pl w4 P1
wait for P2 to finish
pk w2 P2
pl w2 LA4
pk w5 LB1 ---------->
start F1 cycle for LA EVEN THOUGH
IT
HAS ONLY TWO SUBSTRATES because a
substrate was picked from the other
lock, refill LA with w9 and w10
pl w5 P2
wait for P3 to finish
pk w3 P3
pl w3 LB1
pk w6 LB2
pl w6 P3
wait for P1 to finish
pk w4 P1
pl w4 LB2
pk w7 LB3
pl w7 P1
wait for P2 to finish
pk w5 P2
pl w5 LB3
pk w8 LB4
pl w8 P2
wait for P3 to finish
pk w6 P3
pl w6 LB4 ---------->
start F1 cycle for LB because LB is
full, wait until LA F1 finishes (LA
has w9 in LA1 and w10 in LA2)
pk w9 LA1
pl w9 P3
wait for P1 to finish
pk w7 P1
pl w7 LA1
pk w10 LA2
pl w10 P1
No more substrates to pick - start pipeline drain
wait for P2 to finish
pk w8 P2
pl w8 LA2
wait for P3 to finish
pk w9 P3
pl w9 LA3
wait for P1 to finish
pk w10 P1
pl w10 LA4 ---------->
start F1 cycle for LA because LA is
full
EXAMPLE 2
Dual-pan robot
pl w1 to LA1
(Atmospheric robot 76 fills the locks)
pl w2 to LA2
pl w3 to LA3
pl w4 to LA4 ---------->
start LA phm
pl w5 to LB1
pl w6 to LB2
pl w7 to LB3
pl w8 to LB4 ---------->
start LB phm (locks full)
pk w1 LA1
(fill cluster pipeline)
pl w1 P1
pk w2 LA2
pl w2 P2
pk w3 LA3
pl w3 P3
pk w4 LA4
(pipeline full)
wait for P1 to finish
pk w1 PI
pl w4 P1
pk w5 LB1 ---------->
start LA F1 cycle because substrate
was picked from the other lock,
refill LA1 with w9 and LA2 with w10
pl w1 LB1
(same slot as the most recent input
substrate came from)
wait for P2 to finish
pk w2 P2
pl w5 P2
pk w6 LB2
pl w2 LB2
wait for P3 to finish
pk w3 P3
pl w6 P3
pk w7 LB3
pl w3 LB3
wait far P1 to finish
pk w4 P1
pl w7 P1
pk w8 LB4
pl w4 LB4 ---------->
start LB F1 cycle because LB is full
wait for P2 to finish
pk w5 P2
pl w8 P2
pk w9 LA1
pl w5 LA1
wait for P3 to finish
pk w6 P3
pl w9 P3
pk w10 LA2
pl w6 LA2
wait for P1 to finish
pk w7 P1
pl w10 P1
No more substrates to pick - start pipeline drain
pl w7 LA3
(fill slots in active lock)
wait for P2 to finish
pk w8 P2
pl w8 LA4 --------->
start LA F1 cycle because LA is full
wait for P3 to finish
pk w9 P3
wait for LB F1 to finish
pl w9 LB1
wait for P1 to finish
pk w10 P1
pl w10 LB2 ---------->
start LB F1 cycle because no more
unprocessed substrates in batch
Based on the preceding steps it will be appreciated that the rules for scheduling through two alternating pass through locks are:
1) It is preferred only for a dual-pan vacuum robot with 2 positions on the arms that carry the substrates, to swap at the lock (pick first, then place to the same slot);
2) Always put an output substrate to the same slot from which the most recent input substrate came,
ELSE, put it in the next empty slot in the lock that the last output substrate went to,
ELSE, put it in the next empty slot in the other lock;
3) As soon as the lock is filled with processed substrates,
OR as soon as the vacuum robot picks a substrate from the other lock (whichever comes first),
OR if no more unprocessed substrates are in the batch,
start the F 1 cycle (vent, empty using a separate robot in an atmospheric buffer station and refill, pump, home, map).
The same algorithm can be used for transferring substrates from one cluster to another and with clusters that are non-vacuum or that have a controlled atmosphere such as an inert gas. It can also be used with more than two load locks and applied to other pass through modules, such as heaters or coolers connecting two chambers of a 2-TM (transport module) chamber cluster.
It will be seen that unlike the operation of most prior art cluster tools, which use two load locks that each accept a full cassette (or SMIF pod) of wafers and wherein the substrates must return to the same cassette slots that they came from so that each ends up in its slot of origin, the present invention instead returns a substrate to the load lock slot of the substrate most recently sent into the tool for processing (although the external robot may still return the substrate to the cassette slot of origin). Also, venting is started on one lock as soon as the other lock becomes the substrate source rather than waiting until it has been refilled with processed substrates. Thus, the alternate load lock may be vented, refilled, and pumped down, much sooner than before, thereby maximizing throughput and eliminating indexing between the pick and place operations. A comparison of the throughputs (wafers/hr.) achievable with the system of the invention versus that achievable with the prior art systems wherein the substrates are returned to the same load lock slots is shown in FIG. 6 .
As described above, the primary advantage of the present invention is the reduction in manufacturing costs by using lower cost load locks, but maintaining substantially the same throughput as prior art devices. Preferably, the lower cost load locks are non-indexing load locks. However, the method of the present invention could be used with any suitable type of load lock including load locks capable of indexing. The cost saving comes by providing a smaller volume load lock than would otherwise be necessary for a specific throughput with a large volume load lock not using the method of the invention. The invention can be used with a large capacity lock that is smaller than a full batch load lock and still have the same or faster throughput as the full batch load lock. If an indexing load lock is provided, one or both of the substrate transport robots can lack Z-motion capability.
It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims. | A method and apparatus for substrate processing at lower cost than existing processing systems are disclosed, which by implementing an arrangement using load locks of smaller dimensions or of a non-indexing type, as compared to existing large dimension or indexing load locks, along with a substrate loading and unloading technique can achieve the fast throughput of existing systems while reducing the size and cost of the load lock apparatus required. A processed substrate is returned by an internal robot from one of its processing modules to the shelf or slot in the small load lock from which the last substrate was removed for processing by the robot, rather than being returned to the original source shelf or slot from which it was removed for processing, as in the prior art. Also venting for a first one of the load locks is started as soon as the second load lock becomes the substrate source for the internal robot rather than waiting until the first load lock has been refilled with processed substrates. By virtue of these improved operations, small dimension load locks, whether of the indexing or non-indexing type, can be used in place of more expensive large dimension indexing type load locks while maintaining comparable substrate throughputs. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to provisional application 61/235,611, filed Aug. 20, 2009.
FIELD OF THE INVENTION
This invention relates in general to the operation of electrical submersible pumps (ESPs), including Electrical Submersible Progressive Cavity Pumps (ESPCPs) and in particular to changing the pump size of an ESP or ESPCP in a well while ESP or ESPCP system is installed.
BACKGROUND OF THE INVENTION
Electrical submersible pumps (“ESP”) are used to pump wellbore fluids from the depths of the earth to the surface. A typical ESP has a motor, a seal section, and a pump. The motor rotates a shaft inside the seal section. The seal section shaft is connected to the pump. The ESP pump is typically an impeller pump having multiple stages. Each pump stage has an impeller and a diffuser through which wellbore fluid travel. In operation, wellbore fluids enter the first impeller and are accelerated by centrifugal force out of the impeller into the adjacent diffuser. The diffuser then reduces the velocity of the wellbore fluid, converts the high velocity to pressure, and directs the fluid into the next impeller. The pressure of the wellbore fluid is increased with each successive stage as described above, until the fluid is discharged from the pump into tubing that carries the fluid to the surface.
A central pump shaft is connected to the seal section shaft. As the motor rotates, it ultimately causes the central pump shaft to rotate. The central pump shaft passes through each impeller. Keys or splines on the shaft engage corresponding slots on each impeller so that the impellers rotate with the shaft. Spacers are frequently required between the impellers so that the impellers are properly spaced to engage the diffusers.
An electrical submersible progressive cavity pump (“ESPCP”) having a single stator and a rotor may also be used. A typical ESPCP has a motor, a seal section, and a pump. An optional gearbox may also be included. A PCP is a positive displacement pump in which the rotor and the stator have cavities that are filled with fluid. As the rotor is rotated by the motor, fluid is moved upward. For discussion purposes only, ESP is used throughout with the understanding that either an ESP or ESPCP can be used.
Multiple ESP pumps may be connected in series and used in a single well. The ESP pumps are typically driven by a single motor with the shaft running through each of the ESP's. During operation, multiple ESP pumps, or tandem pumps, arranged in this manner provide additional lift that may be necessary to lift the wellbore fluids to the surface.
In wells where tandem pumps are deployed, there may be times during the life of a well where a reduced number of stages or a single ESP pump may be required to lift the fluids. Running the additional ESP pump or increased number of stages is inefficient and expensive. However, to disengage the ESP pumps from the shaft, the ESP string typically requires the ESP system to be pulled out of the well. This is an expensive proposition because production must be stopped during this procedure and subsea replacement can cost millions of dollars.
It would be advantageous to selectively engage or disengage an ESP pump from a drive shaft without pulling the ESP assembly from the well.
SUMMARY OF THE INVENTION
In an embodiment of the present technique, a latching mechanism including a pump shaft adapted to latchingly engage a tool for disengaging the pump shaft of the upper pump from engagement with a second shaft of a lower pump, is shown. The lower pump shaft transfers torque produced by a motor to drive a pump shaft in the upper pump when they are engaged through coupling. This embodiment further includes a sleeve keyed to the pump shaft that is in sliding engagement with a stationary bushing connected to a bearing housing that is located within the pump. A spring retainer may be connected to the stationary bushing to allow for receiving and retaining of a protrusion keyed to the pump shaft. This allows the pump shaft to be maintained in a disengaged position, effectively changing the size and capacity of the ESP assembly. The invention described herein may also be used with progressive cavity pumps to change their size and capacity.
The latching mechanism may also include an adapter located at the upper end of the of the pump that has a cylindrical body. The adapter may have a bypass port and a sleeve that is in sliding engagement with the adapter. The sleeve slides between a closed position and open position to control well fluid flowing through the bypass port. A bypass line may also be used to communicate well fluid from a discharge of a pump driven by the motor to the bypass port of the adapter to thereby bypass the disengaged pump. Thus, the latching mechanism described above advantageously changes the pump size to prevent wasteful operation and without the need for pulling the ESP string to disengage the upper pump.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an ESP with multiple pumps and suspended from production tubing, in accordance with an embodiment of the invention.
FIG. 2 is a sectional view of an adapter for disconnecting the shaft of a pump, in accordance with an embodiment of the invention.
FIG. 3 is a sectional view of an adapter for disconnecting the shaft of a pump with a sleeve in a position to allow flow from a bypass, in accordance with an embodiment of the invention.
FIG. 4A is an enlarged sectional view of an upper pump assembly, in accordance with an embodiment of the invention.
FIG. 4B is an enlarged sectional view of a lower end of an upper pump assembly in accordance with an embodiment of the invention.
FIG. 4C is an enlarged sectional view of a top end of a lower pump assembly in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 , an embodiment of a well pump assembly 10 is shown in a sideview suspended in a well 12 . The pump assembly 10 of FIG. 1 include a motor 11 at its base that is connected on its upper end to a seal section 13 . A lower pump 15 , is attached to the seal section 13 upper end that in turn connects to an upper pump 17 . Seal section 13 equalizes the pressure of lubricant in the interior of motor 11 with hydrostatic well fluid pressure. Motor 11 rotates a shaft (not shown) coupled to a shaft of lower pump 15 ; lower pump 15 shaft is coupled to a shaft of upper pump 17 . During normal operation, motor 11 drives both upper and lower pump 15 , 17 shafts, and fluid discharged by lower pump 15 flows into the intake of upper pump 17 . Pumps 15 , 17 provide the lift required to overcome the initial, high viscosity of the well fluid. In addition, because the head produced by a pump varies with the square of the speed of the motor 11 , running pumps 15 , 17 together compensates for the initially low speed of the motor 11 at startup. However, as well fluid flow increases, fluid temperature also increases to decrease fluid viscosity. Further, lift from one pump is sufficient once higher motor speeds are achieved. Operating the two pumps 15 , 17 can thus be wasteful and inefficient once sufficient lift can be generated by one pump.
In an embodiment of this invention, the upper pump 17 can be selectively disconnected from the lower pump 15 driven by motor 11 without pulling the pump assembly out of the well. Production would be stopped momentarily to disengage the shaft 29 ( FIGS. 2 and 3 ) of the upper pump 17 . After disconnection, the fluid from lower pump 15 could flow though upper pump 17 , and into production tubing 27 for flowing to the surface. The internal parts, such as the impeller, of the disconnected upper pump 17 would introduce a pressure drop that the connected lower pump 15 would have to overcome. Further, the fluid flowing through upper pump 17 rotates its impeller.
The embodiment of FIG. 1 also includes a bypass line 19 connected on one end to a discharge of lower pump 15 . An adapter 21 (which will be described in more detail below) is shown disposed between the upper pump 17 and production tubing 23 . The end of the bypass line opposite the lower pump 15 connects to the adapter 21 .
Alternatively, as shown in FIG. 1 , fluid flow can bypass the disconnected upper pump 17 . When upper pump 17 is disconnected from being driven by the motor shaft, the flow from lower pump 15 can flow through a port 50 ( FIG. 4C ) to the bypass 19 and into adapter 21 . The bypass line 19 registers with a port 20 at its upper end that is formed through the annular adapter wall. An embodiment shown in FIGS. 2 and 3 illustrate one way fluid can selectively be directed through the bypass 19 and adapter 21 and into the production tubing 23 for flowing to the surface. An annular sliding sleeve 25 as shown can be coaxially located within adapter 21 . When upper pump 17 driven by the motor shaft, the sliding sleeve 25 covers the port 20 , thereby blocking flow exiting the bypass 19 . Seals 22 can prevent fluid flow between the sleeve 25 and adapter 21 . To shift sleeve 25 away from the bore 20 as shown in FIG. 3 , a tool 27 shown in dashed outline, such as an overshot tool, can be lowered through tubing 23 ( FIG. 1 ) on wireline 32 . The tool 27 can be conventional, with outward facing, spring loaded lugs that can engage, for example, a shoulder (not shown) on the inner surface of the sleeve 25 .
FIGS. 4A and 4B , illustrate one embodiment for disengaging the shaft 29 of the upper pump 17 from the motor 11 . Although the adapter 21 is shown without the sliding sleeve 25 described above, the sleeve 25 can also be used as previously described. An annular bearing housing 30 located inside the upper pump 17 circumscribes and radially supports the shaft 29 at its upper end. A sleeve 31 , which supports a ball stop 33 , is coaxially mounted around and keyed to the shaft 29 . The ball stop 33 can be a ball with a passage drilled through it and a key formed within the passage that can engage a slot on the shaft 29 . Alternatively, a slot could be formed within the passage in the ball stop 33 that could receive a key or rib formed on the shaft 29 . A conventional split ring assembly (not shown) can be used to lock the ball stop 33 to a location on the shaft 29 or alternatively, retaining rings 38 , 39 can be keyed to the shaft 29 on either side of the ball stop 33 to lock it into place. The ball stop 33 snaps into engagement with a spring retainer or grapple 35 to hold shaft 29 in the upper disengaged position after wireline tool 27 is retrieved. In this embodiment, the grapple 35 is supported from the bearing housing 30 . As shown, the grapple 35 includes cantilevered spring members 34 mounted to the annular bearing housing 30 . An annular bushing 36 connects to one end of the cantilevered spring members 34 and is disposed around the shaft 29 . The spring members 34 have a free end 40 depending downward towards the ball stop 33 and a mid-section 42 profiled similar to the ball stop 33 outer periphery.
During the disengagement operation, the shaft 29 of the upper pump 17 can be disengaged at the same time the tool 27 shifts the sliding sleeve 25 upward to open the bypass bore 20 ( FIG. 3 ). The tool 27 can latch onto the fishing neck 28 of shaft 29 ( FIG. 2 ). The tool 27 can have inward facing, spring loaded lugs that can latch onto the fishing neck 28 . Although the fishing neck 28 is shown with multiple recesses, a single recess can allow engagement with the tool 27 . Once the tool 27 latches onto the shaft 29 of upper pump 17 , it is pulled upward sufficiently to cause splines 44 ( FIG. 4B ) at the lower end of the shaft 29 to disengage from a coupling 54 ( FIG. 4C ) secured to a top end of a lower shaft 52 with a pin 60 and running through an axis of lower pump 15 as shown in FIGS. 4B and 4C . This essentially disconnects the upper pump 17 from the lower pump 15 . An annular bushing 62 is disposed around the lower shaft 52 which surrounds a bushing 64 . The bushing 64 is keyed to the lower shaft 52 and is in contact with a sleeve 66 that may also be keyed to the shaft 52 . As in the upper pump 17 , the lower pump shaft 52 is radially supported at its top end to the annular bearing housing 70 of the lower pump 15 .
As shaft 29 moves upward, it also moves sleeve 31 , a bushing 37 keyed to the shaft 29 , and retaining ring 39 also keyed to the shaft 29 , upward relative to the grapple 35 and bushing 36 . The shaft 29 is pulled upward until the ball stop 33 snaps into engagement with the grapple 35 to hold shaft 29 in the upper disengaged position. Bushing 36 on grapple 35 and bushing 37 keyed to the shaft 29 slidingly and coaxially engage when the ball stop 33 snaps into engagement with the grapple 35 . A retaining ring 38 located below the ball stop 33 and keyed to the shaft supports the ball stop 33 and prevents it from moving if the shaft 29 is overpulled. As explained earlier, in this embodiment, the ball stop 33 can be locked into place on the shaft 29 by the retaining ring 38 located below the ball stop 33 and the retaining ring 39 located above bushing 37 . In addition to locking the ball stop 33 in place, in this embodiment the retaining rings 38 , 39 also function to hold the portion of the sleeve 31 and bushing 37 between the retaining rings, in place. To retrieve the tool 27 , a shear pin (not shown) in the tool can be sheared to release from the fishing neck 28 barbs on the shaft 29 . The shaft 29 can be reconnected to lower pump shaft 52 ( FIG. 4C ) and thus the motor by landing a weight bar on the upper end of the shaft 29 . This disengages the ball stop 33 from the grapple 35 , thus allowing the splines 44 ( FIG. 4B ) at the lower end of shaft 29 to reengage the splines 56 and recesses 58 ( FIG. 4C ) on the coupling 54 at the upper end of the lower pump shaft 52 .
In an additional embodiment, shaft 29 and sliding sleeve 25 could be shifted upward by sending power to an electromechanical device permanently mounted to adapter 21 . The electromechanical device would thus disconnect the shaft 29 and open the bypass port 19 . The shaft 29 and sliding sleeve 25 could also be shifted upward by a hydraulically device permanently mounted to adapter 21 .
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. These embodiments are not intended to limit the scope of the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. | A latching mechanism for selectively disengaging an upper pump from a motor in an ESP. The latching mechanism comprises barbs formed on an upper end of an upper shaft that are engaged by a tool to lift the upper shaft until a lower end of the upper shaft disengages from an upper end of a motor shaft. When the upper pump is disengaged from the motor shaft, only a lower pump is driven by the motor and flow of well fluid is circulated past the disengaged upper pump via a bypass line. The upper pump shaft may reengage the motor shaft if additional lift is required. | 5 |
This is a division of application Ser. No. 07/184,926, Filed 04/25/88.
BACKGROUND OF THE INVENTION
This invention relates to molded thermoplastic foam cups.
More specifically, this invention pertains to molded thermoplastic foam cups which exhibit enhanced coffee retention properties.
The manufacture of molded articles, e.g., cups from expanded thermoplastic particles is well known. The most commonly used thermoplastic particles are expandable polystyrene beads known as EPS. Typically, polystyrene beads are impregnated with a blowing agent which boils below the softening point of the polystyrene and causes the impregnated beads to expand when they are heated. When the impregnated beads are heated in a mold cavity, they expand to fill the cavity and fuse together to form a shaped article.
The formation of molded articles, e.g., cups from impregnated polystyrene beads, is generally done in two steps. First, the impregnated polystyrene beads are pre-expanded to a density of from about 2 to about 12 pounds per cubic foot. Second, the pre-expanded beads are heated in a closed mold to further expand the pre-expanded beads and to form a fused article having the shape of the mold. The second step is generally referred to as molding.
The pre-expansion step is conventionally carried out by heating the impregnated beads using any conventional heating medium such as steam, hot air, hot water, or radiant heat. One generally accepted method for accomplishing the pre-expansion of impregnated theromplastic particles is taught in U.S. Pat. No. 3,023,175 to Rodman.
In the manufacture of foam cups, the preferred thermoplastic is expandable polystyrene beads. The polystyrene beads used to make foam cups are generally prepared by an aqueous suspension polymerization process which results in beads that can be screened to relatively precise bead sizes. Typically, bead diameters are within the range of from about 0.008 to about 0.02 inch. Occasionally, cups are made from particles having bead diameters as high as 0.03 inches.
In spite of careful bead size control, one problem which continues to plague the molded cut industry is that cups molded from expandable polystyrene beads exhibit a tendency to leak coffee. The leakage results from penetration of the coffee around the fused polystyrene beads. The present invention provides a molded foam cup which exhibits enhanced coffee retention.
SUMMARY OF THE INVENTION
It has now been found that if at least a portion of the blowing agent is replaced with isopentane, cups molded therefrom exhibit enhanced coffee retention as compared to cups molded from the same expanded thermoplastic beads in the absence of the isopentane.
DETAILED DESCRIPTION OF THE INVENTION
In the practice of this invention, any suitable thermoplastic homopolymer or copolymer can be employed. Particularly suitable for use are homopolymers derived from vinyl aromatic monomers including styrene, isopropylstyrene, alpha-methylstyrene, nuclear methylstyrenes, chlorostyrene, tert-butylstyrene, and the like, as well as copolymers prepared by the copolymerization of at least one vinyl aromatic monomer with monomers such as divinylbenzene, butadiene, alkyl methacrylates, alkyl acrylates, acrylonitrile, and maleic anhydride, wherein the vinyl aromatic monomer is present in at least 50% by weight of the copolymer. The preferred vinyl aromatic monomer is styrene.
The polymer useful in this invention must be in the form of beads, granules, or other particles convenient for the expansion and molding operations. Beads formed from an aqueous suspension process are essentially spherical and are preferred for molding foam cups.
The polymer particles are impregnated using any conventional method with a suitable blowing agent or mixtures thereof. For example, the impregnation can be achieved by adding the blowing agent to the aqueous suspension during the polymerization of the monomers, or alternatively by resuspending the polymer particles in an aqueous medium and then incorporating the blowing agent as taught in U.S. Pat. No. 2,983,692 to D'Alelio. Any gaseous material or material which will produce a gas on heating can be used as the primary blowing agent. Conventional blowing agents include aliphatic hydrocarbons containing 4 to 6 carbon atoms in the molecule, such as butanes, n-pentane, hexanes, and the halogenated hydrocarbons which boil at a temperature below the softening point of the polymer chosen. Mixtures of these blowing agents can also be used. The blowing agents are normally used in amounts of between 3 and 20 weight percent based on the polymer particles. In the present invention, from 5 to 100 weight percent of the total blowing agent must be replaced with isopentane in order to give the desired resistance to leaking of 88° C. coffee from the foam cups molded from the particles.
The invention is further illustrated, but not limited by, the following example wherein all parts and percentages are by weight unless otherwise specified.
EXAMPLE I
A series of runs were carried out as follows:
An initial polystyrene bead slurry was prepared in a 100 gallon reactor having turbine agitator blades and baffles, and temperature control means, and a pressure rating of 150 psig by adding thereto 400 lbs. of distilled water, and 400 lbs. of polystyrene beads having beads size of 98 wt-% through 35 and on 50 mesh (US Standard). While mechanically stirring the bead/water mixture, 2.8 lbs. of tricalcium phosphate, 50.8 g of sodium dodecylbenzene sulfonate, 272 g of polyoxyethylene(20)sorbitan monolaurate, and 417 g of Fischer-Tropsch wax were added and the reactor sealed.
Physical blends of n-pentane and isopentane were prepared in separate vessels using commercial n-pentane and commercial isopentane.
Following the sealing of the reactor vessel, the contents were heated to 70° C. and the addition of the blowing agent was started. The addition of 30.8 lbs of blowing agent over a period of 1.5 hours was accomplished at a rate of 0.342 lbs/min. The amount of blowing agent was calculated to give a final bead hydrocarbon content of 5.7-6.5%. Immediately upon starting the blowing agent addition, the reactor contents were heated from 70° C. to 105° C. over the first hour.
Following the completion of the addition of the blowing agent, the reactor contents were held an additional 0.5 hour at 105° C. and then cooled to 35°-55° C. for processing. The maximum reactor pressure normally occurs at the end of the addition of blowing agent. The typical pressure maximum ranges from 95-115 psig.
Following cool-down, the reactor contents were transferred to an acid wash kettle where the bead/water slurry was acidified to a nominal 1.8 pH using hydrochloric acid. The beads were held in this condition for 0.5 hours and then centrifuged and dried in a fluidized bed dryer. The dried beads were screened through a 35 mesh screen onto a 50 mesh screen. Following screening, the beads were blended with 300 ppm of silicone oil and 1000 ppm zinc stearate in a ribbon or paddle blender.
All of the expandable beads were expanded batchwise with a steam/air mixture at 93° C. in an 11 gallon pre-expander. The pre-expanded beads were aged 4-24 hours before molding into cups.
Cup molding was carried out using smooth wall molds to produce a 6 oz cup, a 12 oz cup and a 16 oz cup. The cup molding machine was set to a steam header pressure of 80 psig for the 12 oz cups and 110 psig for the 6 and 16 oz cups. A Handicup molding machine was used for the 12 oz cups, while a Thompson molding machine was used for the 6 and 16 oz cups. A back pressure of 28 psig was used for the 12 oz cups and 33 psig for the 6 and 16 oz cups. The total molding cycle for the 6 oz cups took 6.4 seconds per cup and consisted of fill time 1.4 second, dwell time 1.7 second, cook time 1.3 seconds, and cool time 2.0 seconds. Forty cups were molded from each run and allowed to age overnight before testing. Ten cups of each run were subjected to coffee retention testing as follows: Coffee at 88° C. was poured into each cup and the side walls and bottom of each cup containing coffee was observed for coffee stains or leakage every 15 minutes over a four hour period.
The mean time to failure (MTF) of each ten cup sample was calculated by adding the time to failure for each cup (the 15 minute period during which a cup exhibits leakage or staining is recorded as the time to failure for that cup) and dividing the total time by the number of cups tested. The maximum MTF value if none of the ten cups in a run exhibited any stain or leakage is 4.0 hours. The minimum MTF value if all ten cups fail within the first 15 minutes is 0.25 hour.
Coffee retention testing was repeated on a second set and a third set of ten cups of each of the runs 2 weeks and 1 month after the first test. The results of the coffee retention testing are shown in Table I. The additive level is the weight-% of isopentane per total weight of blowing agent in the beads.
TABLE I______________________________________ 1 Day 2 Week 1 MonthAdditive Age Age AgeLevel.sup.(a) % F MTF % F MTF % F MTF______________________________________6 oz Cup0 70 2.2 100 0.7 100 0.75 100 1.5 100 0.7 100 0.710 80 2.1 100 1.5 100 0.920 40 3.0 100 1.0 100 1.050 40 3.0 100 1.5 100 0.9100 40 3.0 100 1.4 100 0.912 oz Cup0 0 >4 80 1.7 50 2.85 0 >4 20 3.3 70 2.510 0 >4 0 >4 0 >420 0 >4 30 3.0 0 >450 0 >4 10 3.8 0 >4100 0 >4 0 >4 0 >416 oz cup0 0 >4 100 1.5 100 0.85 0 >4 40 3.1 0 >410 0 >4 0 >4 0 >420 0 >4 0 >4 0 >450 0 >4 0 >4 0 >4100 10 3.7 10 3.7 50 2.4______________________________________ .sup.(a) Percent isopentane in blowing agent mixture, remainder is npentane. % F = percent failure. MTF = Mean time to failure in hours. | Cups have been molded from expandable styrene polymer particles having a portion or all of the blowing agent replaced by isopentane. Cups molded from these beads were coffee leak tested and generally exhibited enhanced retention of coffee. | 2 |
TECHNICAL FIELD
[0001] The present disclosure relates to a support bracket assembly, specifically a support bracket assembly used to support an interlocking ceramic tile system within a vortex finder of a cyclone separator.
BACKGROUND
[0002] A vortex finder is a cylindrical structure (also known as center pipe, dip tube, immersion tube, thimble, gas tube) inside a cyclone separator where this cylinder provides improved particle separation from a particle-laden gas stream.
[0003] A key part of electrical generating power plants and cement manufacturing plants is the cyclone separator. The purpose of the cyclone separator is to separate particulates from a particle-laden gas stream. The cyclone separator is typically arranged as a vertical cylinder with a conical section at the bottom and a cylindrical outlet duct at the top. The cyclone inlet stream consists of a mixture of flowing gases and solids.
[0004] Cleaner gas exits the top of the cylinder, while particulates exit through the bottom of the conical portion. The incoming gas-particle mixture enters near the top of the cylindrical portion where the gas-particle mixture is forced to rotate around the axis of the cylinder. When the velocity of the gas-particle mixture reaches sufficient flow conditions, the rotating flow causes centrifugal forces to spin the heavier particles outward and along the inside walls of the cyclone separator. These heavier particles will eventually flow downward due to gravitational forces towards the lower cone. The spinning gases and a portion of the lighter particles will remain closer to the central axis of the cyclone separator and flow upwards through the vortex finder and out the exit tube. The lower conical section of the cyclone collects the heavier particles where these heavier particles exit through the bottom outlet nozzle.
[0005] The tube at the top of the cyclone separator is more commonly known as a vortex finder. Typically the vortex finder tube extends below the cyclone roof. The diameter and length of the vortex finder is sized to provide optimum pressure drop and particle separation efficiency of the cyclone separator system.
[0006] It is common for a vortex finder in a power plant or cement plant to be fabricated using either metal or ceramic tiles. Since a typical power plant and cement plant vortex finder is exposed to extreme temperatures, e.g., operating temperatures of approximately 1700° F. (927° C.), a common problem with a metallic vortex finder is to find the metallic parts excessively warped and distorted after only about one year in operation. A metallic vortex finder must be fabricated using expensive alloys that must withstand both high temperature and high velocity of erosive particles that flow through the cyclone. Repairs to a steel vortex finder require either replacement of the damaged parts or specialized heat-treating and welding procedures. In both repair scenarios, replacement or steel repairs can result in excessive maintenance costs and loss of operational profit.
[0007] In a power plant or cement manufacturing plant, the pressure-containing shell of a cyclone separator is typically made of steel, such as carbon steel. The dimensions of a cyclone separator are dependent on the plant's designed operating conditions. As one example, the vertical height of a cyclone separator may be 62 feet (18.9 meters) from the bottom of the cone to the top of the vortex finder and 28 feet 10 inches (8.8 meters) outside diameter. For this cyclone separator, the vertical height of the vortex finder will typically measure approximately 8 feet (2.4 meters) with an inside diameter of 13 feet 9 inches (4.2 meters). The normal internal operating temperature within the cyclone can be approximately 1700° F. (927° C.).
[0008] Because of the internal operating temperature, the cyclone separator pressure-containing steel shell may be insulated with internal insulating materials such as bricks, refractory concretes, ceramic insulating blankets, shaped ceramics, or combinations thereof. These internal lining materials are selected to maintain their functional ability at the operating temperature while being exposed to corrosive gases, anticipated mechanical loads and the erosive action of high velocity solids traveling along the exposed surfaces.
[0009] An alternative to a metallic vortex finder, a vortex finder may also be constructed of a series of interlocking pre-cast ceramic tiles, shapes, or elements that are combined to form a cylindrical structure. Vortex finder ceramic material must handle the anticipated mechanical loads, maintain functional ability at the operating temperature while being exposed to corrosive gases and the erosive action of high velocity solids traveling along the exposed surfaces.
[0010] Interlocking ceramic tiles are known in the art, e.g., pre-cast and pre-fired ceramic interlocking dog-bone shapes. Specifically, interlocking tiles manufactured by M.H. Detrick Co., described in U.S. Pat. No. 4,977,838 as a square wall may be modified into a cylindrical system of interlocking ceramic tiles. Also, The A.J. Weller Corporation offers WellerHASLE® interlocking ceramic elements.
[0011] Attaching the series of interlocking ceramic elements to the inner wall of the cyclone separator outlet duct has presented a number of challenges. Installation of the ceramic elements requires skilled craftsmen to level the tiles and set each tile at the spacing required to form a uniform cylindrical shape of the completed assembly. A system for supporting the weight of the interlocking ceramic elements and for allowing for easy installation of the interlocking ceramics will result in improved dimensional controls and labor cost savings.
[0012] One prior art system of supporting the interlocking ceramic elements involves a steel ring with metallic arms welded to the inside diameter of this ring. The outside diameter of the steel ring has metal horizontal braces that are welded to the steel ring and to the inner wall of the cyclone separator outlet duct. The steel ring, metallic support arms and connecting arms are fabricated using high temperature stainless steel alloy. The steel ring support system is more difficult to install than the present invention because: (1) the metallic support arms must be carefully placed and welded to the steel ring which makes small adjustments time consuming and labor intensive and (2) it is not possible for the steel ring to be fabricated in a perfect circle which can result in dimensional problems and out of roundness of the final ceramic tile assembly.
[0013] Therefore, it is desirable to provide a support bracket assembly system that supports the interlocking ceramic elements while allowing for an easy installation of the elements. The present invention provides for such a support bracket assembly system, which supports the weight of the tiles during construction, provides a simple means to level the tiles while allowing for horizontal adjustment between the elements.
SUMMARY
[0014] One embodiment of the present invention is a support bracket assembly comprising two end plates, a support arm plate, and two horizontal flat bars. The support arm plate is located in between the two end plates in a horizontal direction and comprises three sections: two top sections and one bottom section, wherein a first of the two top sections extend longer than the two end plates in a radial direction. The two horizontal flat bars extend through the two end plates in the horizontal direction, wherein a first horizontal flat bar is located below the first top section of the support arm, and wherein a second horizontal flat bar is located in between a second top section of the support arm and above the bottom section of the support arm plate.
[0015] There may be a gap in the radial direction in between the support arm plate and the first of the two horizontal flat bars. There may be gap in the radial direction in between the support arm plate and the second of the two horizontal flat bars. The end plates may comprise a rectangular slot shaped to receive the first horizontal flat bar. The end plates may comprise a rectangular hole shaped to receive the second horizontal flat bar. The end plates, support arm, and flat bars may be made of stainless steel alloy. The support bracket assembly may weigh approximately 40 pounds (18.1 Kilograms).
[0016] In one embodiment, support arm plate is about 1.5 inches (38 millimeters) thickness. The first top section of the support arm plate may have a rounded tip to receive a ceramic vortex finder element. The support arm plate is located substantially in the middle of the two end plates in the horizontal direction and is anvil-shaped. The support arm plate extends about 4 inches (102 millimeters) longer that the end plates in the radial direction.
[0017] The support bracket assembly may be used to support a ceramic vortex finder element. Thus, another embodiment of the invention is a support bracket assembly and ceramic vortex finder element. Further, another embodiment of the invention is a plurality of support bracket assemblies, wherein each support bracket assembly supports a ceramic vortex finder element.
[0018] Another embodiment of the invention is a series of interlocking ceramic elements, wherein the interlocking ceramic elements form a vortex finder, wherein the series of interlocking ceramic elements comprises a plurality of support bracket assemblies and a plurality of interlocking ceramic elements, wherein at least one ceramic element is supported by the support arm plate of the at least one support bracket assembly. Another embodiment of the present invention is a vortex finder comprising a series of interlocking ceramic elements and a plurality of support bracket assemblies.
[0019] Another embodiment of the invention is a method of installing a series of interlocking ceramic elements to an inside wall of a cyclone separator outlet duct. The method comprises the steps of: (1) prefabricating a plurality of support bracket assemblies; (2) welding the end plates of each support bracket assembly to the inside wall of the cyclone separator outlet duct; (3) placing a ceramic element on each support arm plate of each support bracket assembly; (4) interconnecting a first row of interlocking ceramic elements, wherein a plurality of elements of the first row of interlocking elements is supported by a support bracket assembly; (5) welding the support arm plate of each support bracket assembly to the horizontal flat bars of each support bracket assembly once the first row of elements is in place; (6) interconnecting a second row of interlocking ceramic elements, wherein the second row of elements is supported by the first row of elements; and (7) interconnecting a plurality of rows of interlocking ceramic elements, wherein each row of elements is supported by a preceding row of elements.
[0020] There have thus been outlined the more important features of the invention in order that the detailed description that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and which will form the subject matter of the claims appended hereto.
[0021] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
[0022] As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be used as a basis for designing other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
[0023] All dimensions are stated in U.S. customary units unless specifically noted otherwise.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings, which are incorporated in and form a part of the specification, illustrate various embodiments and, together with the description, serve to explain the principles the various embodiments.
[0025] FIG. 1 is a side view of an end plate, which forms part of a support bracket assembly.
[0026] FIG. 2 is a side view of a support arm plate, which forms part of a support bracket assembly.
[0027] FIG. 3 is side view of a support bracket assembly attached to the inside wall of a cyclone separator outlet duct.
[0028] FIG. 4 is a top view of a support bracket assembly attached to the inside wall of a cyclone separator outlet duct.
[0029] FIG. 5 is a top view of a plurality of support bracket assemblies attached to the inside wall of a cyclone separator outlet duct.
[0030] FIG. 6 is a perspective view of a series of interlocking ceramic elements being supported by a plurality of support bracket assemblies forming a vortex finder.
DETAILED DESCRIPTION
[0031] Some power and cement plants currently have a cyclone separator with a vortex finder constructed of a series of interlocking ceramic tiles. While the present example describes a vortex finder in a power plant cyclone separator, other cyclone separator units may also function using an interlocking ceramic tile system and the support bracket system described herein. The present invention may also be used in the power, cement, or petro-chemical industries.
[0032] The support bracket assembly may be described as a fixed cantilever support bracket. The support bracket assembly is comprised of five main pieces: two end plates, one support arm located in between the two end plates, and two horizontal flat bars extending through the two end plates. The support bracket assembly is fixed to the inside wall of the cyclone separator outlet duct at the two end plates. The support bracket assembly extends from the wall in a radial direction. The support bracket assembly has a height (vertical direction) and a width (horizontal direction). The horizontal flat bars lie in the horizontal direction. The support arm bears the load of the interlocking ceramic elements. The support arm is located substantially in the middle of the two end plates.
[0033] FIG. 1 shows the side view of one of the identical end plates 1 . The end plate is four-sided, with side 2 to be attached to the inside wall of the vortex finder. For example, the height of the end plate is about 8 inches (203 millimeters) vertical direction), the length about 9 inches (229 millimeters) in the radial direction, and the thickness of about 0.5 inches (13 mm) in the horizontal direction. The end plate 1 has two rectangular slots 3 and 4 through which to place the two horizontal flat bars. The rectangular hole 3 is a four-sided hole through the end plate 1 . Rectangular slot 4 is cut into the end plate 1 . Both rectangular slots 3 and 4 of the end plate 1 may be approximately 2.75 inches (70 millimeters) in length and 0.75 inches (19 millimeters) in height. In one embodiment, each of the two end plates 1 weighs approximately 7.9 pounds (3.6 kilograms).
[0034] FIG. 2 demonstrates the side view of the support arm 5 , which has an asymmetrical anvil-shape. The support arm 5 may be about 6.75 inches (171 millimeters) in height (vertical direction), about 12.5 inches (318 millimeters) in width (radial direction), and about 1.5 inches (38 millimeters) thick (horizontal direction). The support arm has three sections: section 6 and 7 on top, and section 8 on bottom (vertical direction). In between sections 6 and 8 there is a 0.75 inch (19 millimeters) gap (vertical direction). Section 7 is about 4 inches (102 millimeters) longer in width (radial direction) than the end plate 1 . The tip of section 7 is what attaches to the ceramic element. The tip of section 7 has a radius of about 0.5 inches (13 millimeters). There is a dimple or hole in the ceramic element which receives the tip of section 7 of support arm 5 . The tip of section 7 is rounded because the internal shape of the mating ceramic element is rounded. If the tip of section 7 had a sharp edge, the sharp edge of the metallic support arm may cause the ceramic tile to crack when operating loads are applied. The first of the horizontal flat bars fit between sections 6 and 8 (vertical direction). The second horizontal flat bar sits below section 7 of support arm 5 (vertical direction). Sections 6 , 7 , and 8 are all approximately 3 inches (76 millimeters) in height (vertical direction). The radii at 9 , 10 , and 11 are approximately 0.125 inches (3 millimeters). The radius in the bottom section 8 is about 0.5 inches (13 millimeters). In one embodiment, the support arm 5 may weigh approximately 15 pounds (6.8 kilograms).
[0035] FIG. 3 demonstrates a side view of the support bracket assembly including end plate 1 , support arm 5 , and horizontal flat bars 12 and 13 . The flat bars 12 and 13 have the same thickness, approximately 0.75 inch (19 millimeters) (vertical direction), but are not the same size. Flat bar 12 is 2.75 inches (70 millimeters) in width (radial direction), while flat bar 13 is 3 inches (76 millimeters) in width (radial direction). Each flat bar 12 and 13 are approximately 7.25 inches (184 millimeters) in length (horizontal direction). Flat bar 12 weighs approximately 4.3 pounds (2 kilograms), while flat bar 13 weighs 4.69 pounds (2.1 kilograms). There is a 0.5 inch (13 millimeters) gap 14 between the horizontal bar 12 and end plate 1 and support arm 5 . The end plate 1 attaches to the inside wall of the cyclone separator outlet duct 15 . The gap 14 in between the horizontal bar 12 and the support arm 5 allows for radial adjustment of the ceramic elements during installation. Specifically, this gap 14 allows for the diameter of the cylinder of interlocking ceramic elements to be adjusted during the installation of the individual elements. This adjustment is necessary because it is unlikely that the cyclone separator outlet duct and the circular interlocking ceramic element system will be a perfect circle.
[0036] FIG. 4 demonstrates a top view of the support bracket assembly including end plates 1 , support arm 5 , and horizontal flat bars 12 and 13 . Before installation of the support bracket assemblies, the two flat bars 12 and 13 are welded to the end plates 1 . This welded pre-assembly (two flat bars 12 and 13 welded to the end plates 1 ) may be completed in a fabrication shop. See welds at 16 , 17 , 18 , and 19 . Installation of the support bracket assemblies includes welding the end plates 1 to the inside wall of the cyclone separator outlet duct 15 at welds 20 , 21 , 22 and 23 . After all support bracket assemblies are installed, craftsmen will install the top row of interlocking ceramic vortex finder elements. While installing the top row of elements, the support arms 5 can be adjusted. The support arm 5 may move horizontally, along the direction of the horizontal flat bars 12 and 13 , during installation of the interlocking ceramic elements, allowing for easier installation of the intricate puzzle of interlocking pieces. After all support arm adjustments are completed, the support arm 5 may be fillet welded to the horizontal flat bars 12 and 13 at welds 24 , 25 , 26 and 27 . The fillet welds at 24 , 25 , 26 , and 27 are only necessary to fix the location of the support arms, but these welds do not support any weight of the interlocking ceramic elements. All welds 16 - 19 and 24 - 27 are specifically located away from the high stress and high temperature area of the vortex finder.
[0037] The support bracket assembly may be made of a suitable chromium-nickel austenitic stainless steel alloy that can handle the operating loads while being exposed to the operating temperature and corrosive gases. There are several suitable alloys that may be used, such as alloys included in the American Iron and Steel Institute 300 series (AISI 300) stainless steels. The combination of the two end plates, the support arm, and the two flat bars, in one embodiment, will weigh a total of approximately 40 pounds (18.1 kilograms).
[0038] The interlocking ceramic elements may be pre-cast and pre-fired ceramic tiles or other suitable material, such as a refractory concrete. The ceramic elements form a cylindrical wall along the inner wall of the outlet duct of the cyclone separator. This cylindrical wall of interlocking elements may be approximately 16 feet (4.9 meters) in diameter and approximately 10 feet (3 meters) in height. A plurality of the first layer of ceramic elements is supported by a plurality of support bracket assemblies. Each row of dog-bone shaped ceramic elements provides support for the adjacent lower row of elements. This configuration results in lower rows of interlocking ceramic elements that are hanging from the top row of ceramic elements.
[0039] FIG. 5 demonstrates a top view of one embodiment of the invention, wherein thirty support bracket assemblies 28 attach to the inside wall of the cyclone separator outlet duct 15 . In this embodiment, the steel shell inside diameter of the cyclone separator outlet duct is approximately 16 feet (4.9 meters). Each of the 30 support bracket assemblies supports a corresponding ceramic element in the first row of the interlocking cylindrical wall. For these example dimensions and number of elements, this results in a rate of one support bracket assembly per 1.7 feet (one support bracket assembly per 518 millimeters) measured along the circumference. The top row of ceramic tiles includes special ceramic elements that are intended to be supported by the steel support arm of the bracket assembly. These special ceramic elements, or “support lugs” each are constructed with a special indentation or dimple in them so as to receive the tip of the steel support arm.
[0040] In the first row of interlocking ceramic elements, every other element is a “support lug”, which is molded in the shape of a half element so as to create the interlocking row of elements. The support lug is similar to a single dog-bone shape ceramic element cut in half in the vertical direction. In the first row of interlocking ceramic elements, only the ceramic support lugs are eligible to be supported by the steel support arm of the support bracket assembly.
[0041] The next layer of ceramic elements is then fitted below the first layer. There is no need for half pieces (support lugs) after the first row. The ceramic elements are arranged in a plurality of layers or rows of interlocking ceramic elements shaped such that each lower layer of elements hangs from the adjacent upper layer of elements in an interlocking fashion. Some vortex finder assemblies may contain as many as 8 to 12 rows or layers of interlocking elements. During installation of the vortex finder tiles, each complete layer or row of elements are put into place, one after the other, starting from the top layer that contains the support lugs which are supported by the steel support bracket assemblies.
[0042] FIG. 6 is a perspective view of a series of interlocking ceramic elements being supported by a plurality of support bracket assemblies forming a vortex finder. Continuing with the current example, FIG. 6 demonstrates thirty support bracket assemblies 28 supporting thirty ceramic element half pieces (support lugs) 29 . All the support lugs 29 of FIG. 6 are supported by the support bracket assemblies 28 . In between each support lug 29 is a full ceramic element 30 . There are ten rows of interlocking ceramic elements in FIG. 6 . The cyclone separator unit is not shown in FIG. 6 so that the interlocking ceramic elements may be viewed unobstructed. However, as described, the support bracket assemblies 28 are to be welded to the inside of the inside wall of the cyclone separator outlet duct.
[0043] The ceramic elements may be constructed as dog bone or “I” shaped. The density of the ceramic element may be approximately 180 pounds per cubic foot (2.9 grams per cubic centimeter). The element may have a thickness (radial dimension) of approximately 3.25 inches (83 millimeters), an inner-chord length of approximately of approximately 7.75 inches (197 millimeters), an outer-chord length of approximately 11.75 inches (298 millimeters), a height of approximately 13.25 inches (337 millimeters). The weight of a ceramic element can be approximately 39 pounds (17.7 kilograms). Therefore, a support lug (half element) weighs approximately 20 pounds (9 kilograms). The ceramic elements are pre-cast and heat treated before use. The selected ceramic element material and heat treatment must provide an element that can handle the operating loads, operating temperatures and corrosive environment.
[0044] Continuing the example wherein thirty support bracket assemblies are used in a cyclone separator outlet duct that has a diameter of approximately 16 feet (4.9 meters), there may be approximately 572 interlocking ceramic elements. The total of all 572 elements can weigh approximately 21,000 pounds (9,525 kilograms). The static load on each steel support bracket will be 1/30 th of the total load or approximately 700 pounds (317.5 kilograms).
[0045] The support bracket assemblies have been described for use in a vortex finder of a cyclone separator. Modifications and alterations will occur to other cyclone separator systems upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiments be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
[0046] While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims. | The present disclosure relates to a support bracket assembly and multiple support bracket assemblies supporting a series of interlocking ceramic elements. The interlocking ceramic elements form a cylindrical structure that is an important component of a cyclone separator. Several industrial plants have large cyclone separators such as power plants and cement plants where it is necessary to remove solids from a particle-laden gas stream. The support bracket assembly is comprised of five main components: two end plates, a middle support arm which is capable of supporting a ceramic element, and two horizontal flat bars that fit through the two end plates and the middle support arm. | 1 |
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/788,458, filed Feb. 21, 2001, which was a continuation-in-part of U.S. patent application Ser. No. 09/739,834, filed Dec. 7, 2000, which was a divisional application of U.S. patent application Ser. No. 09/277,944, filed Mar. 29, 1999, now U.S. Pat. No. 6,171,466.
FIELD OF THE INVENTION
[0002] The invention relates in general to an apparatus and method for achieving electrophoretic focusing, and in particular to an apparatus for achieving electrophoretic separation and purification which is characterized by a separation chamber formed between two precision-pore, insulated screens and which also includes inlet and outlet ports, a plurality of purge chambers for extracting extraneous fractions and for providing thermal cooling, a plurality of electrodes to provide a transverse electric field in the separation chamber, and pumping means for pumping sample, carrier buffer, purge buffer and electrode rinse buffer through the apparatus, and a method of employing this apparatus to achieve separation and collection of a desired component from a biological or chemical sample.
BACKGROUND OF THE INVENTION
[0003] There are two electrokinetic methods that have had success separating biological materials, namely, zone electrophoresis and isoelectric focusing. Electrophoresis is the movement of suspended or dissolved charged particles in response to an applied electric field. The rate of motion depends upon the charge, size and shape of the particles and specific properties of the solvent buffer and its container. In zone electrophoresis, the components in a short sample zone are separated by the action of the electric field. The injection of a narrow, uniform zone and the absence of dispersive fluid flows are necessary conditions for successful operation. Significant sources of dispersion are: 1) uneven (parabolic) flows; 2) electrohydrodynamic flows; 3) molecular diffusion; 4) thermal convection; 5) sedimentation; 6) thermally induced sample mobility variations; and 7) electroosmosis.
[0004] In continuous zone electrophoresis (CFE), the electrolyte solution flows in a direction perpendicular to the electric field and the mixture to be separated is inserted continuously into the flowing solution. Components of the mixture are deflected according to their electrophoretic mobilities and can be collected continuously in a finite array of collection ports after their migration. Svensson and Braftsten were the first to report a method for carrying out electrophoresis continuously. They used a lateral electric field in a narrow Plexiglas box packed with glass powder as an anti-convective medium. Durrum modified the above configuration by replacing the glass-filled box with a filter paper curtain, hanging in a free vapor space. While both of these methods demonstrated continuous electrophoresis, they both used a stabilizing medium. Anticonvective media cause many problems such as reduction of the flow capacity by their presence, electroosmosis in the interstices, adsorption of the sample and “packing or eddy diffusion”. Efforts were then made to do continuous electrophoresis in a free fluid. Dobry and Finn (U.S. Pat. No. 3,149,060) were the first to report continuous flow free fluid electrophoresis in a rectangular chamber with a cross-section of low aspect ratio, hence providing little resistance to thermal convective flow disturbances. This configuration was limited to very low electric fields and required the use of buffer thickening agents to suppress convective eddies. Philpot described a continuous flow electrophoresis system with the electric field applied across (perpendicular to) a thin film of liquid. He later wrapped his thin film geometry into a thin annulus surrounded by two concentric cylinders (electrodes). The outer cylinder rotated to provide a stabilizing velocity gradient.
[0005] Mel in 1959 reported the first use of a high aspect ratio rectangular separation chamber using a lateral electric field. The “thin” chamber of 0.7 cm thickness provided the necessary wall interaction to suppress thermal convective flows to the extent that a less viscous free flow buffer could be used. This design served as the impetus for the development of the conventional CFE machines of the 60's and 70's with their chamber cross-section of high aspect ratio and laterally directed electric fields. During this time frame, Hannig and his co-workers developed CFE by making the chamber cross-sections even thinner, approaching 0.25 cm for some designs. Unfortunately, the gains made in suppressing thermal convection were wiped out by electrohydrodynamic interaction with intrinsic chamber fluid flows to cause crescent-shaped distortions. Nevertheless, a variety of CFE instruments were manufactured according to the designs of Hannig (in Germany) and Strickler (in the US) (U.S. Pat. No. 3,412,008) and several hundred instruments were used in laboratories around the world. Rhodes and Snyder subsequently devised a technique to minimize these flow distortions (U.S. Pat. No. 4,752,372).
[0006] While the concept of using a counter flow to oppose the electrophoretic migration velocity has long been considered an attractive means to achieve a focusing effect, no method has been found to provide the uniform velocity field necessary to bring this concept to fruition. Richman patented a counter-flow method where axial bands of electroosmotic coatings of varying zeta potential would “straighten” distorted sample bands (U.S. Pat. No. 4,309,268). The method was impractical because most coatings change with time and there exists no spectrum of coatings with respect to zeta potential. A more practical approach that did not use counter-flow was suggested by Strickler wherein the CFE was divided into two vertical compartments, each with a different wall coating, so that the combined electroosmotic flow would yield a more coherent sample band. Subsequently, Ivory used counter-flow to increase sample residence time in a recycling CFE. Egen, et al. have also devised a counterflow gradient focusing method (U.S. Pat. No. 5,336,387).
[0007] While the crescent phenomenon was long known to cause untenable sample stream distortion in CFE instruments, it was not until 1989 that Rhodes and Snyder showed that electrohydrodynamics transforms initially circular sample streams into ribbons that initiate the crescent shaped distortions. The operation of CFE devices was labor intensive and unreliable due to contamination of the closely spaced chamber walls and the resultant electroosmotic flow variations through the chamber.
[0008] Isoelectric focusing (IEF) is an electrophoretic technique that adds a pH gradient to the buffer solution and together with the electric field focuses most biological materials that are amphoteric. Amphoteric biomaterials such as proteins, peptides, nucleic acids, viruses, and some living cells are positively charged in acidic media and negatively charged in basic media. During IEF, these materials migrate in the pre-established pH gradient to their isoelectric point where they have no net charge and form stable, narrow zones. In spite of the very long time required for isoelectric focusing, this process yields high resolution bands because any amphoteric biomaterial which moves away from its isoelectric point due to diffusion or fluid movement will be returned by the combined action of the pH gradient and electric field. The focusing process thus purifies and concentrates sample into bands that are relatively stable. This is a powerful concept that has yielded some of the highest resolution separations, especially when coupled with electrophoresis in two-dimensional gels.
[0009] IEF had its practical beginning in the mid-1950's when Kolin first demonstrated the concept of focusing ions in a pH gradient by placing a molecular sample between an acidic and a basic buffer and applying an electric field. Although the constituents focused rapidly, the gradient soon deteriorated due to the concurrent electrophoretic migration of all of the buffering ions. The synthesis of stable carrier ampholytes by Vesterberg and their successful commercial development led to broad use in gels or other restrictive media to suppress electroosmosis and thermal convection during analytical separations.
[0010] The high resolution achieved by IEF encouraged many attempts to develop a preparative version of the process. This proved to be much more difficult for IEF than zone electrophoresis because of the variable fluid properties and sample characteristics within the chamber leading to changing values of electroosmosis and thermal convection during the separation. Various CFE devices were modified to run with an amphoteric mixture instead of buffer but the problems (long focusing time requiring a slow flow through the chamber, pH drift toward the cathode, reduced voltage/current levels for acceptable heating and convection) became insurmountable. Bier developed an external cooling system, added sensors and demonstrated the improved focusing with recycling (U.S. Pat. No. 4,362,612). Bier then added a stabilizing assembly rotation to the membrane segmentation and a novel collection system (U.S. Pat No. 4,588,492) which led to the Roto-Phor from Bio-Rad (Hercules, Calif.).
[0011] Unfortunately there are drawbacks to IEF that have limited its applications. The rate of electrophoretic migration of each charged species decreases progressively as it approaches its isoelectric point and long residence times are required for high resolution. Proteins have reduced solubility at their isoelectric point although precipitation of the concentrated bands can be minimized by addition of detergent. Additional problems relate to the commercial amphoteric solutions, including: 1) difficulty of extracting the separated proteins, peptides, etc., from the amphoteric solutions because of their similar physical properties and interactions; 2) chemical toxicity; 3) handling problems; and 4) cost. IEF has also been hindered by problems during the transition from an analytical system to a preparative system that have limited its intended use. It is thus highly desirable to develop a focusing system for separating biological molecules and other components in a mixture which is able to avoid all of the problems of the prior art and which can achieve high resolution of separation in an analytical or a preparative mode through a practically unlimited scale-up potential. It is also highly desirable to develop an electrophoretic focusing system which can control the adverse effects of Joule heating and electrohydrodynamics on the electrophoretic separation procedure.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to provide a preparative-scale free-fluid electrophoretic separator with high resolution as well as an analytical capability commensurate with capillary zone electrophoresis. The particular mode of high-resolution separation as provided by the present invention, which is referred to as electrophoretic focusing, combines features of electrophoresis and isoelectric focusing to accomplish large scale purifications and fractionations that have not been possible before now.
[0013] Many research and applications tasks with biological materials require a large source of highly purified biologically active molecules. The diverse supply of materials for biotechnology ranging from plants to genetically derived sources are placing increased demands on separation and purification. Existing preparative separation techniques yield products with a variety of impurities that can be measured analytically but not removed. Analytical techniques have been perfected in recent years but attempts to scale these techniques into larger production have relied on generally increasing the physical dimensions instead of investigating a new technique. It is an advantage of the focusing device of the present invention that it will be able to purify biological materials in amounts and to purity levels above those now obtainable.
[0014] In accordance with the present invention, there is provided an electrophoretic focusing apparatus and method which is useful in achieving the separation and purification of particular components of a mixture of biological or chemical materials. The general purpose of the invention is a continuous processing system that separates and purifies any soluble or microparticulate sample that acquires a surface electric charge when immersed in a polar (e.g. aqueous) fluid environment. It combines the best features of electrophoresis and isoelectric focusing in a novel device that incorporates a combination of transverse electric field and buffer flow field to focus and collect any selected biological component. Although the high resolution achievable by focusing is familiar to isoelectric focusing, electrophoretic focusing avoids many of its problems, such as the need for complex buffers and the long times required for the molecules to reach their isoelectric point. This new concept incorporates a large-gap chamber and control of all sources of sample dispersion. The design of the electrophoretic focusing chamber combined with the orientation and magnitude of the electric fields and buffer flows are planned to eliminate sample dispersion. The large gap will keep sample away from the walls as well as increase its throughput.
[0015] It is another object of the present invention to develop a separation device capable of high speed and short residency through the use of high voltage gradients. These high voltage gradients are produced by relatively low voltages applied across the narrow chamber dimensions. The goal of high resolution of separation can be achieved through the use of the present invention in an analytical or a preparative mode through a practically unlimited scale-up potential. A further goal is to control the adverse effects of Joule heating and electrohydrodynamics.
[0016] These and other objects and benefits are achieved by the use of the present invention which provides a number of innovations and insights with regard to fundamental fluid and thermal geometries and operations. The focusing is accomplished with a minimum of sample migration which leads to a higher resolution in a shorter time. Adiabatic thermal conditions in the lateral (scale-up) dimension permit a large increase in throughput at no apparent loss of resolution. Active cooling limits the maximum chamber temperature and its relationship to the chamber orientation and buffer fluid transport is such as to limit thermal convection. Porous, rigid screens permit a controlled focusing cross-flow which balances the electrophoretically-driven sample velocity. In the preferred method in accordance with the invention, separation and collection of at least one component from a mixture of components is obtained by the steps of (a) providing an apparatus comprising a separation chamber and a plurality of purge chambers, and establishing a first buffer flow in the separation chamber in the axial direction, said first buffer flow having a first flow rate; (b) establishing a second buffer flow in the separation chamber consisting of two flows on either side of the first flow that converge on the first flow at the chamber entrance and diverge from the first flow at the chamber exit; (c) establishing a third buffer flow in each of at least two purge chambers in the axial direction, said second buffer flow having a second flow rate, said second buffer fluid flow having a second flow rate higher than that of the first flow rate; (d) introducing two precision-pore screens that partition the said separation chamber from each of the two said purge chambers; (e) establishing a fourth buffer flow by the biasing of the purge valves to control said fourth buffer flow from one of the purge chambers through a precision-pore screen transversely into the separation chamber, then out of the separation chamber through the second precision-pore screen into a second purge chamber, thus providing the required uniform focusing fluid velocity in the separation chamber; (f) introducing the mixture of sample components with the said first buffer flow directly into the separation chamber flow entrance or through at least one injection port located in the separation chamber interior; (g) controlling the second buffer flow to converge and thin the first buffer flow with sample components at the separation chamber entrance and then diverge and extract sample components at the separation chamber exit; and (h) applying an electrical potential transversely across the separation chamber in the form of a constant voltage gradient to impart electrophoretic velocity to the fractional components in the separation chamber in the transverse direction perpendicular to the first buffer flow direction and parallel to the fourth buffer flow direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a schematic view of the analytical configuration of the present invention, taken in the axial, transverse and lateral directions.
[0018] [0018]FIG. 2 is a schematic representation of the preparative configuration of the present invention, taken in the axial, transverse and lateral directions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The detailed description of the preferred embodiments below is to be taken in conjunction with the drawing figures as described above wherein like numerals represent the same elements in the different figures. In addition, the disclosures of the parent applications of the present application as set forth above are considered part of the present specification and are incorporated by reference as if set forth in full herein.
[0020] The principle of electrophoretic focusing utilized in conjunction with the present invention consists of opposing the electrophoretic sample velocity with a uniform fluid flow transverse to the direction of carrier flow through the chamber. The uniqueness of this invention is how this principle is used in conjunction with a constant voltage field to achieve a novel and powerful method of continuous sample separation. This result is achieved by using a uniform cross-flow in opposition to an electric field to confine, or focus, a particular fraction in the separation chamber.
[0021] If the electric field is configured in the transverse direction (instead of the lateral direction as with CFE), electroosmotic flow becomes negligible and the viscous parabolic flow is orthogonal to the migration direction and hence also ceases to be a factor. Since the transverse migration is now in the narrow chamber dimension, the sample residence time is quite short and normally resolution will suffer. However, if a cross-flow is used, the sample will be held in the chamber by the cross-flow, thus improving the resolution by some calculable amount. This solution to the problems of CFE has been considered by past inventors but the problem of obtaining a uniform cross-flow combined with an area electrode associated with the broad chamber wall has kept this idea from realization. As the details of the invention show, this problem is solved by a unique utilization of micro-pore, thin, rigid, insulating screens.
[0022] The electrophoretic separator of the present invention is primarily characterized by a separation chamber formed between two precision-pore insulated screens. The perforations permit transverse fluid flow through the chamber to effect a separation of one or multiple species and also to provide cooling in the chamber interior. This unique use of cross-flow focuses one sample fraction continuously in the chamber when using a constant electric field to oppose the cross-flow. Since the separation is carried out in the direction transverse to the carrier buffer flow, the focusing is accomplished with a minimum of sample migration which leads to a higher resolution in a shorter time. The relatively short transverse dimension allows the use of a high voltage gradient derived from a low source voltage. When high resolution is desired, i.e., analytical separations, the sample is injected and collected in singular injection and collection ports so that the chamber is only partially filled with sample. When high throughput i.e., preparative separations are desired, the sample fills the entire chamber. This latter configuration provides a homogeneous medium between the chamber walls and eliminates conductivity gradients which produce destructive circulatory flows through Joule heating and electrohydrodynamics.
[0023] Another problem with existing continuous flow devices is the method of sample collection. The separated fractions must be collected by a finite number of collection ports which ultimately limit resolution. Collection for a batch process, such as chromatography or capillary electrophoresis, poses no such problem as each separate fraction can be individually collected over a variable time interval rather than a limited fixed distance interval between each adjacent collection port. This invention can collect fractions as a function of time by varying the cross-flow velocity to produce a histogram similar to that obtained from chromatography or capillary electrophoresis.
[0024] In the preferred embodiment of the present invention, separation and collection of at least one component from a mixture of components is obtained by the steps of (a) providing an apparatus comprising a separation chamber and a plurality of purge chambers, and establishing a first buffer flow in the separation chamber in the axial direction, said first buffer flow having a first flow rate; (b) establishing a second buffer flow in the separation chamber consisting of two flows on either side of the first flow that converge on the first flow at the chamber entrance and diverge from the first flow at the chamber exit; (c) establishing a third buffer flow in each of at least two purge chambers in the axial direction, said second buffer flow having a second flow rate, said second buffer fluid flow having a second flow rate higher than that of the first flow rate; (d) introducing two precision-pore screens that partition the said separation chamber from each of the two said purge chambers; (e) establishing a fourth buffer flow by the biasing of the purge valves to control said fourth buffer flow from one of the purge chambers through a precision-pore screen transversely into the separation chamber, then out of the separation chamber through the second precision-pore screen into a second purge chamber, thus providing the required uniform focusing fluid velocity in the separation chamber; (f) introducing the mixture of sample components with the said first buffer flow directly into the separation chamber flow entrance or through at least one injection port located in the separation chamber interior; (g) controlling the second buffer flow to converge and thin the first buffer flow with sample components at the separation chamber entrance and then diverge and extract sample components at the separation chamber exit; and (h) applying an electrical potential transversely across the separation chamber in the form of a constant voltage gradient to impart electrophoretic velocity to the fractional components in the separation chamber in the transverse direction perpendicular to the first buffer flow direction and parallel to the fourth buffer flow direction.
[0025] In addition, further information regarding the preferred method of the present invention is provided in the following description of the Analytical Configuration and Preparative Configuration modes of the invention.
[0026] I. Analytical Configuration
[0027] [0027]FIG. 1 shows the three-dimensional chamber in its analytical configuration with the different flows and flow regions. The chamber is comprised of a plurality of flow regions or sub-chambers, such as the five elements 1 , 2 , 3 , 4 and 5 . In the preferred embodiment, the separation chamber 1 is bounded by two fine mesh, precision pore, insulated screens 22 and 23 . Carrier buffer Qci enters the chamber through ports 7 and 8 while sample Qs is injected through port 6 . The converging flows in the vicinity of the injection point are significant as will be discussed later. The buffer and injected sample lamina flow through the chamber as shown with center plane velocity Uc. The focused sample fraction Qf exits the chamber through port 21 while the carrier buffer Qco exits through ports 19 and 20 .
[0028] As shown in FIG. 1, the separation chamber 1 is flanked by two purge chambers 2 and 3 . The purge flows Qp enter through ports 9 and 10 and cause a velocity profile Up in the purge chambers. The purge flows exit through ports 17 and 18 and through purge valve A, 15 and purge valve B, 16 . The relative purge valve openings set the purge flow out Qpa and Qpb and thus regulate the amount of cross-flow in the separation chamber which will be discussed in detail later. An electric field Eo is impressed in the separation chamber 1 by electrodes 26 and 27 . These electrodes are located in the electrode chambers 4 and 5 , respectively. Rinse flows Qe enter the chamber through ports 11 and 12 to expel electrolysis products through ports 13 and 14 . Membranes 24 and 25 isolate the electrode chambers from electrolysis gas and products while allowing current flow to maintain the electric field.
[0029] If the upper electrode 26 is negative and the bottom electrode is positive, an electric field Eo exists in the separation chamber 1 which will cause a negatively charged sample to migrate down (negative transverse direction) against the uniform transverse focusing velocity Vc as determined by the relative settings of the purge valves 15 and 16 . Consider a sample fraction of electrophoretic mobility μ i =Vc/Eo that has been injected through the injection port 6 located at the separation chamber center plane. The sample fraction μ i will remain in the vicinity of the center plane of the separation chamber 1 and move through it with a carrier buffer velocity Uc and be collected at the collection port 21 . All other sample (mobility different than μ i ) will either exit through ports 19 and 20 in the separation chamber or through screens 22 and 23 and hence through ports 17 or 18 . A sample fraction scan can be made by varying Vc while the voltage gradient Eo should be maximized to obtain the highest separation performance. The eluent Qf from collection port 21 enters an ultraviolet detector and is displayed as a conventional histogram.
[0030] Thus, by varying the transverse focusing flow Vc against a constant electric field Eo, a scan of the fraction content of a sample can be made. This type of scan of a sample is unique in a separation device since the peak histogram is a function of the time rate of change of the focusing velocity Vc and is given by μ=Vc/Eo. The time rate of change Vc is set by precision control of the purge valves 15 and 16 . This allows real time control of the separation process. Continuous sample collection can be made by stopping the scan at a peak of interest, or made after the complete scan has been made by recovering the transverse velocity Vc corresponding to a peak of interest.
[0031] The peak values are detected by a liquid chromatography flow cell and detector system and fed back into the computer to achieve a feed-back control system. Cooling of the electrode chambers 4 , 5 is provided by the electrode rinse flow while the purge flow Up provides cooling for the rest of the chamber. The flow velocity Up in the purge chambers 2 , 3 may be up to ten times that in the separation chamber 1 in order to accomplish this purpose. The pore size of the screens 22 , 23 is small (presently 0.005 cm hole, 50% open area) and thickness 0.5 mm. While the small holes will dampen disturbance flows between the separation chamber 1 and the purge chambers 2 , 3 , it is advisable to consider pressure drops in the separation and purge chambers so that b p 2 /b c 2 =Up/Uc where b p and b c are the thickness of the purge and separation chambers respectively. Confining the sample stream to the center region of the chamber avoids adsorption of the sample material on the containing “walls”, screens 22 and 23 . Evacuated glass side walls will preclude heat transfer in the lateral direction. This condition eliminates any variance in this direction so that scale-up of the sample stream width is unlimited.
[0032] Referring to FIG. 1, it can be seen that the injection port 6 is part of the chamber end wall. This configuration provides a simple means to manufacture very thin injection ports using spacer materials. Further, the carrier buffer flows from ports 7 and 8 converge at the sample injection port entrance to the chamber. This configuration is capable of producing injection lamina on the order of a micron. With Q s <<Q ci , an acceleration of the sample lamina occurs at the injection point caused by the converging buffer flows. Since continuity must be maintained, the sample lamina becomes thinner by the ratio of these flows. Thus, very thin lamina can be injected and collected instead of the usual cylindrical configurations.
[0033] II. Preparative Configuration
[0034] [0034]FIG. 2 shows the three-dimensional chamber in its preparative configuration with the different flows and flow regions. The chamber is comprised of a plurality of flow regions or sub-chambers, such as the five elements 1 , 2 , 3 , 4 and 5 . In the preferred embodiment, the separation chamber 1 is bounded by two fine mesh, precision pore, insulated screens 22 and 23 . Carrier buffer enters the chamber mixed with the sample as Qs through port 6 . The buffer and sample fill the entire separation chamber and flow through the chamber as shown. The focused sample fraction Qf exits the chamber through port 21 .
[0035] As shown in FIG. 2, the separation chamber 1 is flanked by two purge chambers 2 and 3 . The purge flows Qp enter through ports 9 and 10 and cause a velocity profile Up in the purge chambers. The purge flows exit through ports 17 and 18 and through purge valve A, 15 and purge valve B, 16 . The relative purge valve openings set the purge flow out Qpa and Qpb and thus regulate the amount of crossflow in the separation chamber. An electric field Eo is impressed in the separation chamber 1 by electrodes 26 and 27 . These electrodes are located in the electrode chambers 4 and 5 , respectively. Rinse flows Qe enter the chamber through ports 11 and 12 to expel electrolysis products through ports 13 and 14 . Membranes 24 and 25 isolate the electrode chambers from electrolysis gas and products while allowing current flow to maintain the electric field.
[0036] If the upper electrode 26 is negative and the bottom electrode is positive, an electric field Eo exists in the separation chamber 1 which will cause a negatively charged sample to migrate down (negative transverse direction) against the uniform transverse focusing velocity Vc as determined by the relative settings of the purge valves 15 and 16 . Consider a sample fraction of electrophoretic mobility μ i =Vc/Eo that has been injected through the injection port 6 located at the separation chamber center plane. The sample fraction μ i will remain in the separation chamber 1 and move through it with the carrier buffer flow and be collected at the collection port 21 . All other sample (mobility different than μ i ) will exit the separation chamber through screens 22 and 23 and hence through ports 17 or 18 . A sample fraction scan can be made by varying Vc while the voltage gradient Eo should be maximized to obtain the highest separation performance. The eluent Qf from collection port 21 enters an ultraviolet detector and is displayed as a conventional histogram.
[0037] Thus, by varying the transverse focusing flow Vc against a constant electric field Eo, a scan of the fraction content of a sample can be made. This type of scan of a sample is unique in a separation device since the peak histogram is a function of the time rate of change of the focusing velocity Vc and is given by μ=Vc/Eo. The time rate of change Vc is set by precision control of the purge valves 15 and 16 . This allows real time control of the separation process. Continuous sample collection can be made by stopping the scan at a peak of interest, or made after the complete scan has been made by recovering the transverse velocity Vc corresponding to a peak of interest.
[0038] The peak values are detected by a liquid chromatography flow cell and detector system and fed back into the computer to achieve a feed-back control system. Cooling of the electrode chambers 4 , 5 is provided by the electrode rinse flow while the purge flow Up provides cooling for the rest of the chamber. The flow velocity Up in the purge chambers 2 , 3 may be up to ten times that in the separation chamber 1 in order to accomplish this purpose. The pore size of the screens 22 , 23 is small (presently 0.005 cm hole, 50% open area) and thickness 0.5 mm. While the small holes will dampen disturbance flows between the separation chamber 1 and the purge chambers 2 , 3 , it is advisable to consider pressure drops in the separation and purge chambers so that so that b p 2 /b c 2 =Up/Uc where b p and b c are the thickness of the purge and separation chambers respectively. Confining the sample stream to the center region of the chamber avoids adsorption of the sample material on the containing “walls”, screens 22 and 23 . Evacuated glass side walls will preclude heat transfer in the lateral direction. This condition eliminates any variance in this direction so that scale-up of the sample stream width is unlimited.
[0039] In order to use electrophoretic focusing for high resolution separations, the crossflow must be essentially constant along both axial and transverse directions. For example, when purge valve A is open more than purge valve B, there is a net flow from the lower purge chamber 3 through the separation chamber 1 and into the purge chamber 2 . It is the transverse component of this flow velocity in the separation chamber which constitutes the focusing cross-flow. To assure that this cross-flow is constant in the axial direction, the flows and chamber dimensions must be carefully designed. Solving second order differential flow equations for the total flow system shows that indeed the cross-flow does not significantly change axially if the chamber geometry and operating parameters are selected so that the transverse flow resistance in the screen is much larger than the axial flow resistance in the purge chambers.
[0040] Considering the plurality of flows necessary for operation, it is obvious that a simple and effective method of flow control must be devised. Since the pressure drops in the chamber are on the order of 1 Newton per meter squared, it would require an expensive and complicated method of control by pressure measurement and feedback. The problem is solved through the use of high resistance flow restrictors in the entrance and exit flow regions, allowing flow to be supplied by a single pump for each purpose. A lumped flow resistance model was developed for the electrophoretic focusing chamber. If the entrance flow restrictors have a much greater flow resistance than the chamber components, then the flow will be equally split into each purge chamber and no measurement or control system is necessary. This configuration was also used to split the entrance and exit carrier buffer flows. The electrode rinse flows are not synchronized or controlled but only set at a sufficient magnitude to remove the electrolysis products.
[0041] As the Figures show, the temperature gradient that affects the sample mobility is co-directional with the sample migration. This is in contrast to zonal techniques such as CE and CFE where the temperature gradients are perpendicular to the sample migration. When the electrophoretic migration and temperature gradient are co-directional as they are in electrophoretic focusing, it can be shown that the temperature-induced mobility dispersion is compensated by the temperature-induced variations in buffer dielectric constant and buffer electrical resistivity. Taking the variations of mobility, buffer dielectric constant and resistivity from experimental data, the classic mobility equation (Smoluchowski) can be solved as a function of temperature. The results show that any temperature-induced mobility dispersion is compensated by the temperature-induced buffer properties and thus does not vary significantly over a temperature range from 0° C. to 40° C.
[0042] The referenced publication by Rhodes, et al., 1989, predicts that a thin ribbon or lamina is the most stable sample configuration against the electrohydrodynamic distortion that occurs when the sample stream introduces a conductivity perturbation in the flowing buffer. Recently, it was found that electrohydrodynamic disturbances are minimized when the separation chamber is completely full of sample or when the sample lamina are very thin. These conclusions were demonstrated experimentally and have been verified using numerical analysis. Using this effect in the chamber design, numerical analysis has shown that the very thin sample streams produce electrohydrodynamic flows two orders of magnitude less that electrophoretic migration velocities. For the preparative configuration, the separation chamber can be filled with sample. This will reduce the conductivity variation in the separation chamber and produce equal attenuation of the electrohydrodynamic flow.
[0043] The above description presents only illustrative embodiments of the present invention, and it will be clear to one skilled in this art that additional alternative embodiments not set forth above will fall within the scope of the invention.
[0044] The following example is present only as illustrative of the present invention, the scope of which is defined by the claims appended hereto, and thus is not intended to limit the invention in any manner.
EXAMPLE
[0045] Prototype instruments in accordance with the present invention were built and tested as set forth in the descriptions given above. Dye materials, methyl orange and coomassie blue, were mixed with a phosphate buffer to test the deflections according to electrophoretic mobility and focusing cross-flow. After stabilizing the mixture stream by adjustments of the pumps and valves, the electric field was applied resulting in the deflection of the various colored components out of the separation chamber, through the screens into the purge chambers. The introduction of the appropriate cross-flow brought all sample streams back to a condition such that the lowest mobility yellow dye entered the “left” purge chamber, intermediate dye, red, focused in the central separation chamber and the highest mobility dye, blue, remained deflected in the “right” purge chamber. These separations were shown to be stable and repeatable. | An apparatus and method is described for obtaining a preparative-scale, free-fluid electrophoretic separator with high resolution as well as an analytical capability commensurate with capillary zone electrophoresis. The electrophoretic focusing apparatus and method of the present invention features a separation chamber bounded by planar precision-pore, insulated screens, a plurality of purge chambers, a plurality of electrode chambers, and a plurality of pump means. The separation device of the invention is capable of high speed of separation and short residency of sample through the use of high voltage gradients which are produced by relatively low voltages applied across the narrow chamber dimensions. The present invention is also highly flexible, with operation in a constant electric field, continuous flow mode which permits scanning of the sample fraction content and display in a conventional histogram format. The present apparatus and method thus achieves high resolution of separation in an analytical or a preparative mode through a practically unlimited scale-up potential, and controls the adverse effects of Joule heating and electrohydrodynamics on the electrophoretic separation procedure. | 6 |
RELATED CASES
This application is a continuation of a first copending application Ser. No. 763,686, filed Aug. 8, 1985, and said copending application is a continuation-in-part of our originally filed application Ser. No. 621,499, filed June 18, 1984; this application is also a continuation-in-part of a second copending application Ser. No. 751,150, filed July 2, 1985, now abandoned, and said second copending application is a division of said original application Ser. No. 621,499, filed June 18, 1984.
BACKGROUND OF THE INVENTION
The invention relates to a medical appliance, and particularly to a medical appliance for applying pressure to a part of a human body for the purpose of stimulating blood circulation.
Such medical appliances are known which comprise a double-walled sheath adapted to fit over a limb, for example an arm or a lower leg portion, to be treated, and a pump apparatus arranged to inflate and deflate the sheath cyclically thereby to apply a pumping action to the limb and thus assist venous blood-flow therein.
A particular disadvantage of such known appliances is that they cannot be used when the limb to be treated is also to be encased in a plaster cast, or sometimes when the limb has been subjected to surgery; neither is it possible, with any appliance which completely encloses the extremity, for the physician to use the pin-prick test for nerve response at the involved extremity, nor can he carry out the essential tests to assess the state of circulation at the extremity.
A further disadvantage of known appliances is that they are not suited to continuous use by the patient.
These disadvantages are particularly significant in relation to appliances for use on feet and legs where as is known stimulation of blood flow is desirable when the limb cannot be used for walking.
We have discovered a venous pump mechanism in the sole of the human foot, which under normal walking conditions for the foot, serves to return blood from the leg into the abdomen with no assistance from muscular action.
BRIEF STATEMENT OF THE INVENTION
According to one aspect of this invention, there is provided a medical appliance comprising an active device for engagement, in use, with at least the sole of a human foot, said device being operative, in use of the appliance, to apply pressure cyclically to said sole thereby to stimulate the venous pump mechanism in said foot.
Essentially, said active device includes means to render said device active when said foot is not in use for ambulation.
According to another aspect of this invention there is provided a medical appliance comprising an active device in the form of an inflatable bag shaped for engagement with at least the sole of a human foot; inflation means connected to the bag and capable of inflating the bag rapidly; means to deflate the bag; and means to secure the bag to a human foot such that when being inflated the bag applies pumping pressure to the sole of the foot.
DETAILED DESCRIPTION
Several medical appliances embodying this invention will now be described by way of example with reference to the drawings, in which:
FIG. 1 is a view of a first appliance, partly broken away and in position on a human foot;
FIG. 2 is a view similar to FIG. 1, but showing a sectional view of a second appliance;
FIG. 3 is a sectional view on the line III--III in FIG. 2;
FIG. 4 is a partly broken-away plan view of the bag 1 as an article of manufacture, with a phantom superposed plan view of a right foot, positioned for wrapped application of the bag thereto;
FIGS. 5 and 6 are views similar to FIG. 4, to show modifications;
FIG. 7 is a side view in elevation of a slipper applied over a foot that has been fitted with one of the inflatable foot-pump bags of the invention;
FIG. 8 is a plan view of the slipper of FIG. 7, in flattened condition, prior to use; and
FIG. 9 is a simple graph of pressure as a function of time, in aid of discussion of use of the invention.
Referring to FIG. 1, the appliance here shown comprises an inflatable bag 1 formed of plastics material and shaped for engagement with the sole 10 of a human foot 11 in the plantar arch thereof. The bag 1 is connected by way of a flexible pipe 2 to a pump apparatus 3 by which the bag 1 can be inflated.
The bag 1 may be secured to the foot 11 by a suitable slipper or by adhesive means, but in the form shown a cloth sling 4 embraces the bag 1 and is secured over the instep 12 of the foot 11. Padding material can be located between the sling 4 and the instep 12 if necessary or desirable, and it is generally recommended that a porous knitted or other fabric such as stockinette be first applied to the foot so as to be interposed between the bag 1 and the foot, thus allowing for ventilation and preventing chafing of the skin.
The sling 4 and bag 1 are covered by a cloth slipper 6 which covers the majority of the foot 11.
In use of the appliance when secured to a foot as shown in FIG. 1, the pump apparatus 3 operates rapidly to inflate the bag 1 which then applies a pumping pressure to the sole 10 of the foot 11, and also urges the ball and heel of the foot away from each other, thus flattening the plantar arch as would occur if the foot 11 were placed on the ground during normal ambulation, thereby stimulating venous blood-flow. Preferably, an accumulator tank is part of the pump apparatus 3, the same being continuously charged by the pump, and having the capacity for rapid inflation of bag 1. A valve arrangement (not shown) in the pump apparatus 3 then allows the bag 1 to deflate, whereafter the bag 1 is again inflated, the inflation/deflation cycle being repeated as long as treatment with the appliance is required.
Preferably inflation of the bag 1 is effected in two seconds or less to provide a satisfactory pumping action, while deflation of the bag 1 can take as long as is necessary for the return of blood to the veins of the foot 11.
The treatment thus provided simulates walking on the foot 11, and thereby improves venous blood circulation in a person being treated who would normally be unable to walk or possibly even stand on the foot.
As a modification of the above described appliance, the valve arrangement in pump apparatus 3 can be dispensed with, the pump apparatus serving only for cyclic inflation of the bag 1, and at least the surface of the bag 1 in contact with the foot 11 being formed with air leakage orifices thereby to be permeable to air, or being made of a microporous material which is inherently permeable to air. Such a surface can be provided as will give the required period for deflation of the bag 1.
Such an appliance gives the advantages that the air leaving the permeable surface of the bag 1 serves to prevent accumulation of moisture between the bag 1 and the foot 11, thus enhancing the comfort of the user of the appliance and making skin problems less likely.
A particular advantage of the appliance of this invention is that it can be used when a foot is to be encased in a plaster cast, or when the leg carrying the foot 11 has been subjected to surgery.
FIGS. 2 and 3 of the drawings show an appliance in position for use on a human foot 11 under a plaster cast 100, the same reference numerals as used in FIG. 1 being used for corresponding parts.
The appliance shown in FIGS. 2 and 3 is similar to that shown in FIG. 1, but is larger and extends not only under the sole 10 of the foot 11, but also around the inside of the foot 11 and over the instep 12 of the foot 11.
For use, the appliance is positioned on the foot 11 and the plaster cast 100 is then formed over the bag 1 as required, with the pipe 2 from the pump apparatus 3 passing either through a hole in the cast 100 or out of one end of the cast 100.
The bag 1 can be maintained in a partially inflated condition while the plaster cast 100 is formed, whereby allowance for subsequent possible swelling of the foot 11 is made.
More specifically, and referring to FIG. 4, the inflatable bag 1 may comprise two like panels 20-21 of flexible material, such as PVC or polyurethane film, peripherally sealed to each other as indicated at an edge seam 22. Each of the panels comprises a plantar-aspect sole area A configurated to longitudially lap essentially only the region of the foot between adjacent plantar limits of the ball and heel of the foot and to extend into substantial register with lateral limits of the sole of the foot. The panels 20-21 also include, within the same peripheral seal or seam 22, an integrally formed dorsi-medial area B which extends transversely from one edge of the sole area A to a transverse extent which is substantially as great as the longitudinal extent of the area A. Typically, as shown, for a foot requiring a shoe in the size range 9 to 12, the longitudinal extent X of the bag is about 7 inches, and the maximum transverse extent Y of the bag is about 8 inches. The average width W X of the sole area A is about 2.75 inches, and the reduced width W Y of the area B is about 2 inches. Along its anterior edge C, the area B is substantially straight and transverse to the longitudinal direction of area A, and along its posterior edge D, the area B tapers in a concave sweep from the heel end of area A to the narrow transverse end at width W Y , the inlet pipe 2 having sealed entry approximately midway along the edge D.
What has been described for bag 1 in connection with FIG. 4 will in and of itself serve well as an article of manufacture, in that gauze, muslin, bandage material and/or adhesive tape may be relied upon to retain a circumferentially wrapped application of the bag to the foot. However, to facilitate such application without initial resort to such other instrumentalities, FIG. 4 additionally illustrates present preference for a flexible anchor tab 23 (as of vinyl sheet) which is integrally formed with bag 1, extending laterally beyond seam 22 at the longitudinal edge E of area A, and for a tie-down tab 24, also integrally formed with bag 1 beyond seam 22 at the transverse tip F of area B. A peel-off strip 25 of suitable release material is shown protecting a coating of pressure-sensitive adhesive on tab 24, so that upon adhesive exposure, tab 24 may be "tacked" to tab 23 in adjustably secured retention of the wrapped application of bag 1 to a foot. And it will be noted for the preferred relatively non-stretch nature of the material of tabs 23-24, a "tacked" circumferential completion of the wrap, involving a fastening of tab 24 in outer-end lap with tab 23, will enable circumferential hoop-tension force to be relatively uniformly distributed along substantially the entire longitudinal extent of area A, i.e., along edge E, thus assisting in the plantar-arch flattening action described above. Plural apertures in the larger tab 23 allow ventilation of adjacent skin but do not impair the indicated distribution of hoop-tension force.
Although FIG. 4 happens to show bag 1 for the situation in which the right foot is accommodated, it will be understood that the same accommodation to the left foot may also be made by the same article of manufacture. In application to the left foot, the plan view of FIG. 4 is reversed, from left to right, by placing the panel 20 on the bottom, beneath panel 21, and the pressure-sensitive adhesive is just as "tackable" to tab 23 as before, except for being engaged beneath tab 23.
As has already been noted, the release of pressure fluid after each pulsed delivery of inflation pressure is suitably via pores or apertures in one or both of panels 20-21. It may be found convenient to manufacture the bag 1 without such pores or apertures, using puncturable material. And the surgeon who makes the fitted application to a patient's foot need only first blow the bag via his mouth, then hold inlet 2 closed with a finger, while he uses a needle or other sharply pointed instrument to make plural punctures of the panel (20 or 21) which is to be adjacent the sole of the patient's foot; such puncturing may proceed while the surgeon squeezes the bag to satisfy himself that the desired degree of fluid leakage will be achieved in use. On the other hand, we prefer that bags 1 be marketed with existing perforations in each of two configurations, one specifically committed to right-foot application and the other specifically committed to left-foot application.
The described bag 1 of FIG. 4 will be seen, in cyclically pressurized use within the circumferential bandage or sling 4 of FIG. 1, or within the cast 100 of FIGS. 2 and 3, to provide a peripherally continuous confinement of the midtarsal and plantar regions of a foot, with the action of rapidly shrinking the confinement in a cyclical pattern of relatively rapid short-duration release from shrink action. More specifically, this confinement and cyclical action may be viewed as the means of providing (a) upward and spreading force at longitudinally spaced plantar regions of the sole of the foot, said regions being essentially limited by and between the ball and heel of the foot and (b) downward force at the region of the midtarsal joint. As a result of the indicated cyclical pattern, the arch is caused to flatten periodically and thus to stretch and neck down the internal sectional area of the veins of the lateral plantar complex, with resulting venous-pump action. Viewed in a still further light, this confinement and cyclical action will be seen as the means of providing vertically opposed squeezing forces between the plantar region of the sole of the foot and the region of the midtarsal joint, to thereby stimulate the venous-pump mechanism of the foot.
In all cases, it is important and deemed significant that neither the distal calf pump nor the proximal calf pump, nor any other of the significant pumps of the venous-return system of the involved leg is actuated in time-coincidence with foot-pump actuation. This fact illustratively enables the described invention to be operative within a cast, or to be operative in a region remote from orthopedic fixation of a damaged tibia, knee, or femur, or to be similarly remote from the region of a vein-transplant operation and thus to relatively rapidly dissipate the pain and swelling which are the normally expected post-operative consequence of such an operation. In spite of the remoteness of foot-pump actuation from these other regions of trauma, the fact of no other pump involvements means that foot-pump driven venous return flow can be substantially unimpeded in its direct delivery to and through the region of trauma.
FIGS. 5 and 6 are further inflatable-bag embodiments of the invention, although they are presently of lesser preference, as compared to the embodiment of FIG. 4.
In FIG. 5, an inflatable bag 30 is longitudinally elongate and corresponds generally to the function and placement of area A of the bag 1 in FIG. 4. Bag 30 thus is designed for application to the plantar region of the sole of the foot, being cyclically inflatable via a flexible inlet pipe 31 sealed to bag 30 via locally sealed access through the peripheral seam 32 of the bag. A perforated flexible tab 33 corresponds to the tab 23 of FIG. 4, and a similar but ultimately more narrow and more extensive tab 34 is connected to the opposite longitudinal edge of bag 30, being adhesively coated and protected by peel-off material 35. A retaining hoop is circumferentially completed by pressure adhesion of tab 34 to tab 33. In a cyclical application of pressure fluid to the device of FIG. 5, it is the longitudinal flattening of the arch which is primarily responsible for foot-pump stimulation.
In the arrangement of FIG. 6, an inflatable bag 40, served by an inlet pipe 41 and peripherally sealed at seam 42 is generally rectangular but elongate in the direction transverse to the longitudinal direction of the foot (phantom outline); and end tabs 43-44 correspond to those previously described, to enable pressure-adhered completion of a circumferential hoop or belt around the midtarsal/plantar regions of the foot. In a cyclical application of pressure fluid to the device of FIG. 6, it is the generally vertical squeezing action at the midtarsal/plantar region which is primarily responsible for foot-pump stimulation, i.e., virtually without any arch-flattening action.
In certain post-operative situations wherein a part of the leg other than the foot is involved, it is therapeutically beneficial not only to operate the foot pump but also to allow the patient a degree of freedom to stand and walk on his installed foot-pump bag 1, or 30, or 40. In such a situation, a fitted slipper 50 is most useful, and may take any one of a variety of forms, so that FIGS. 7 and 8 will be understood to be merely illustrative of one of these forms.
The slipper 50 comprises a sole member 51 of relatively rigid, porous, light-weight material, centrally adhered to a sheet 52 of light-weight duck or canvas, leaving flexible lateral flaps M-N projecting laterally beyond the respective longitudinal side edges of sole member 51; flaps M-N are adapted for wrap-around fit to the particular foot, the lap of flap M over flap N being visible in FIG. 7. Woven-fabric straps 53-54-55-56 have centrally-sewn connection to the underside of sheet 52, at regions marked 53'-54'-55'-56' in FIG. 8, leaving free ends for completion of circumferential fastening of sole member 52 to the foot at each of three longitudinally spaced locations; it is convenient to have one end of each strap fitted with a wire bail, so that the other end of each strap can be threaded through the corresponding bail and be Velcro-fastened against itself, to hold each adjusted strap connection.
A tail portion 52' of fabric sheet 52 extends rearward of a small yieldable heel step 57 at the back end of sole member 51, and tail portion 56 is characterized by like, oppositely directed tabs 58-59, each of which has an exposed patch of Velcro loop material 58'-59'. These patches are selectively engageable with patches 60-61 of Velcro hook material sewn to the underside of panels M-N, as viewed in the sense of FIG. 8. A thin panel 62 of anti-skid material is bonded to the underside of the described assembly, to complete the slipper.
In use, and after installation of an inflatable-bag (1, 30, 40) with its inlet pipe illustratively projecting upward and rearward from the inner lateral side of the ankle, the flaps M-N are first folded into overlap over the midtarsal region, and the straps 53-54-55 set to hold the overlap. Then, tail 56 is folded upward and each of the tabs 58-59 is wrapped around the back of the heel, into completion of Velcro engagements, at 58'-60 and at 59'-61, respectively. The slipper and foot-pump actuator are now in readiness to accept cyclical pressure-fluid stimulation via connection to inlet 2. It will be understood that the relatively rigid sole member 51 provides an excellent reference against which to react, upon bag inflation, for application of arch-flattening and/or midtarsal/plantar squeezing action of the nature discussed above.
As a modification of the appliances thus far shown and described, it will be understood that inflatable foot-pump bag 1 can be incorporated in an article of footwear, such as a conventional boot, to be worn by a person needing to use the appliance.
An inflatable bag 1 of the nature described in connection with FIG. 4 never requires a large volume change in proceeding through its inflation/deflation cycle. The maximum inflated volume is in the order of 300 to 350 cc, and on deflation the inflated volume can be expected to reduce to 100 to 120 cc. Thus, the pressure-fluid supply equipment 3 may be relatively small and convenient for table-top or shelf mounting, with flexible-hose and disconnectable coupling to the inlet pipe 2; this is true, whether the supply and control means 3 is merely timed valving to assure programmed delivery of pressure pulses of a fluid, such as oxygen from a locally available tank supply, or the means 3 incorporates its own pumping and/or accumulator mechanism to provide the needed pressure fluid. Whatever the alternative, standard regulator, bleed orifices, time delay devices and their adjustability are all well known and therefore the supply means 3 may take on a variety of different physical embodiments. What is important, however, is that delivery of pressure fluid to inlet 2 and the bleed of fluid through pores and/or apertures and/or valving in the deflation phase shall meet certain criteria. Presently preferred criteria will be stated in the context of FIG. 9, which shows pressure P to develop quickly in the inflation phase a and to dissipate somewhat exponentially, in the deflation phase b.
Although it has been stated above that bag 1 should be inflated in two seconds or less, it is perhaps more accurate to state that in our experience to date the inflation should be as quick as possible, to imitate the normal impact of the sole of the foot on the ground when walking. Such fast inflation imparts a jerk or sharply pulsed action in return blood flow, and such action is likely to be helpful in preventing venous thrombosis. It is believed that maximum velocity, however transient upon pulsed excitation, is more important than total blood flow. The veins have check-valve formations, and the downstream side of each check valve is a site where stagnation and clotting may occur; it is believed that with bag inflation as rapid as possible, the opening phase for each check valve is correspondingly rapid, thus locally stirring stagnant return-flow blood and reducing the chances of a clotting constriction of return-flow passages.
The peak pressure P for any delivered inflation impulse should be that which is sufficient to produce the appropriate venous impulse, whilst not being too uncomfortable for the patient to tolerate. This will of course mean a different peak pressure P which will be various, depending upon the particular patient and his affliction. However, it can be said that, in our experience to date, a peak pressure within bag 1 (20, 30, or 40) of 200 to 220-mm Hg has been satisfactory, although there may be times when it is advisable to use a peak pressure somewhat greater than 220-mm Hg. Such peak pressure has produced comfortable actuation of the patient's foot pump, in the circumstance wherein the supply apparatus 3 has provided time-switched delivery of oxygen from a pressurized tank and wherein the inflation time a was 0.4 second.
The total period (a+b) of the inflation/deflation cycle will also be various, depending upon the confronting pathological condition and, in particular, on the severity of venous obstruction and on how quickly the physiological venous pump becomes filled. As a rough guide, it can be said that in severe venous obstruction, as in a limb with marked swelling, the period of the cycle might be as frequent as every 10 seconds. In moderate swelling, 30 seconds would probably be adequate, whereas for maintenance purposes a 60-second cycle should suffice. The optimum frequency of the cycle can be audibly determined by the clinician, listening to the flow in the posterior tibial veins with a Doppler monitor.
Although the interval between inflation pulses is very much greater than the indicated rapid inflation time a, deflation should commence automatically at achievement of predetermined peak pressure, and initial deflation should be rapid and follow an exponential pattern. Thus, we currently recommend leakage in bag 1 to the extent that, for example, for a peak pressure P of 210-mm Hg, deflation to 30-mm Hg should be in about one second, and to 20-mm Hg in about 1.9 seconds. A timer, within apparatus 3, reinitiates the cycle upon predetermined time-out of the interval b.
Operations in which the described foot-pump actuating means are likely to be particularly useful include leg fractures and operations around the knee joint, where the leg veins may become compressed either during or after an operation. It has been found very useful in arterial and vein-graft operations, where some of the leg veins have had to be ligated and where the collateral venous-return channel (the long saphenous vein) has had to be removed for use as an arterial graft.
It will be seen that the described uses of the invention involve a method of promoting venous pump action in the leg of a living body and that, from one aspect, steps of the method comprise (a) application of a circumferential tie to the foot at the region of the midtarsal joint, (b) applying upward and spreading force between the circumferential tie and the foot at longitudinally spaced plantar regions of the sole of the foot, said plantar regions being essentially limited by and between the ball and heel of the foot, (c) relaxing said force for a period of time, and (d) cyclically repeating the force-application and force-relaxing steps in a pattern wherein force application is relatively rapid, whereby the arch of the foot is periodically caused to flatten and thus to stretch and neck down the internal sectional area of veins of the lateral plantar complex, with resulting venous-pump action.
From another aspect, steps (a) and (b) of the above method are modified to the extent that the upward and spreading force is in reaction to downward force at the region of the midtarsal joint, i.e., vertically opposed squeezing forces between the region of the midtarsal joint and the plantar region therebeneath. From a still further aspect, steps (a) and (b) may be viewed as establishing a peripherally continuous confinement of the midtarsal and vertically opposed plantar regions of the foot, and developing the squeezing forces through a periodic shrinking of the confinement. | The invention contemplates a non-invasive technique and apparatus for artificially stimulating the venous-return flow of blood from the foot by inducing sharply pulsed squeezing or necking-down of the vessels of the venous-pump mechanism within the foot. The stimulation results from transient flattening of the plantar arch, in that an induced transient spread of the heel with respect to the ball of the foot stretches, and therefore necks-down involved blood vessels; stimulation also results from such a squeeze of the plantar-arch region as to concurrently squeeze the involved blood vessels. Cyclically inflatable devices, local to the foot-pump region, are disclosed for inducing either or both of the indicated actions. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
FIELD OF INVENTION
This invention relates to a unitized masonry structure, particularly structures with post tensioned reinforcement. The present invention relates generally to all general construction where a common mortar and hollow block or brick combination is utilized and to other construction means for structures as well.
FEDERALLY SPONSORED RESEARCH
Not Applicable.
SEQUENCE LISTING OR PROGRAM
Not Applicable.
BACKGROUND
Field of Invention
The new unitized masonry structure described in this specification is a construction system that is designed to easily and quickly install in any location without the need for mortar, water, or power. In the United States alone there are over 4000 block manufacturing companies. Traditionally, building blocks and bricks are attached to each other by either of two methods. The first is by gravity, which includes stacking, arches, and flying buttresses. The second is by mortar and mortar equivalent methods, such as various types of mortar, epoxy, or blocks having their cores concrete filled, with or without reinforcing steel bars (rebars). This attachment includes mortar with reinforcing wire in the joints and also includes attachment between masonry units with concrete and rebars in such shapes as bond beam blocks and pier blocks.
Normally when reinforcement means have been used with block, it is accomplished with either long rebars or long steel rods placed in the cavities. Post tensioning has only been used with a complete stack of block in conjunction with the mortar between each layer. Specialty block systems with rods and plates require complex design and skill.
A. Introduction of the Problems Addressed
Since most masonry structures use mortar, several things are required. First, the mortar requires water. Second, in most cases, the laying of block requires a skilled block or brick mason. Third, a means of power to mix the mortar is normal. Fourth, elaborate bracing 38 and reinforcement is needed until the mortar cures and reaches its strength ( FIG. 3B ). The overall structure is “fragile” to wind, severe temperatures, and other natural weather and environmental conditions. During this time, occupation and use of the structure is unwise. Also, scaffolding 37 often remains in place awaiting cure before additional blocks are added ( FIG. 3A ). If proper preparation and care are not provided to reduce the environmental impacts, the mortar and overall structure may result in cracking and diminished structural strength. Reinforcing means 35 are often provided to improve strength ( FIG. 2D ), but the need to have bracing and other protection in place for many days and weeks is still needed. Finally, once built, the traditional masonry systems become a fixed structure. Unless very special provisions are added to the normal block, rebar and mortar system, the structure is not re-useable and must be “demolished” to be removed.
These stated requirements each limit the use of the traditional masonry with mortar system. The Bolt-A-Blok system facilitates a clear improvement to traditional construction systems and their limitations. Accordingly, it would be advantageous to have a system that does not require special skills to construct; does not need water and power; does not require elaborate bracing; is useable immediately and needs no curing time; and, is re-useable if desired and is not destroyed when disassemble and moved. This improvement would decrease the time to build or rebuild areas and would minimize the restriction of skilled labor. Importantly without the bracing and exposure to weakening by disturbing the mortar, the Bolt-A-Blok system provides a far superior and more consistent strength to the mortar constructed structure.
B. Prior Art
Historically, few patented devices have attempted to address the problem as stated. The building industry has made little progress for a unitized, post tension system. Even so, blocks have required special configurations to even handle rods and plates and then the have taught only limit rods in special blocks. One such device is described in U.S. Pat. No. 5,511,902 (1996) issued to Center which teaches an Instant levy block system. This is a complex, specially made block for constructing a levy, comprising a plurality of blocks, a plurality of connecting pegs, and a plurality of stakes. Each part is uniquely designed and made whereas the Bolt-A-Blok system utilized standard, readily available components.
Another block device is described in A U.S. Pat. No. 5,809,732 which was issued to Farmer, Sr. et al (1998) which teaches a masonry block with an imbedded plate. The concrete masonry block has an external plate or plates that are anchored through the concrete masonry block. The external plates are cast into the concrete masonry block in the mold during casting. These are not regular hollow core blocks available globally as used with the Bolt-A-Blok system.
Another device for construction is taught by U.S. Pat. No. 6,098,357 issued to Franklin et al. (2000). This art discloses a modular pre-cast construction block system with a wall subsystem and a foundation subsystem. The wall subsystem has a number of wall units having cavities and pre-stressed tension cables are cast therein the cavity. This teaches precast walls and through cable which are special made, require water, and are not readily re-useable like the Bolt-A-Blok system.
A re-useable system 32 is taught in the U.S. Pat. No. 6,178,714 issued to Carney, Jr. (2001) (FIGS. 2A and 2B). The rods go through apertures in the special block and the precast structures. The configuration of special length rods, special blocks, special plates and a complex system that requires powered equipment to construct is unlike the simple, available components of the Bolt-A-Blok system.
A mortarless wall structure is taught in U.S. Pat. No. 6,691,471 issued to Price (2004). Here a wall structure comprising of columns of preformed, lightweight, stacked blocks, with the columns of blocks connected to each other by elongated, vertically oriented, support beams. Preferably, the wall structure is operatively connected to a structure by one or more brackets. The beams and blocks are special configuration, not readily available and with limited uses.
Traditional masonry structures which use mortar have several characteristics which merit brief discussion as prior art. Most are constructed such that the roof structure 34 , 39 is attached to a top plate which is anchored by bolts into the hollow cavities ( FIG. 2C and FIG. 3C ). The corners 40 and straight sections 41 often are staggered and have wire mesh and an occasional rebar ( FIGS. 3 D and E). Finally, openings for doors and windows are often breached by pre-cast lintels 42 ( FIG. 3F ).
Other prior art applicable to a thorough understanding of the significant technological advantages and improvements offered by the Bolt-A-Blok system need some discussion of the post tensioning technology used in construction today. Simply put, Post-Tensioning is a method of reinforcing concrete, masonry, and other structural elements. Post-tensioning is still state-of-the-art engineering, but until now it has only been possible to attach multiple concrete units directly to each other with rods and cables. The Bolt-A-Blok system makes possible the post-tensioning of a single masonry unit in a manner that makes it possible to attach additional single post-tensioned masonry units while at the same time combining and maintaining the post-tensioning of all the units.
Traditional post-tensioned units 36 may have various configurations ( FIG. 2E ). To date this technology has been unobvious as being applied at a unitized configuration. Individual blocks are attached to each other and now, as a new combination, perform as if it were all one post-tensioned beam, bridge, wall, or structure. This Bolt-A-Blok system works equally well with all size masonry units.
Traditional Post-Tensioned reinforcing consists of very high strength steel strands or bars. Typically, strands are used in horizontal applications like foundations, slabs, beams, and bridges; and bars are used in vertical applications like walls and columns. A typical steel strand used for post-tensioning has a tensile strength of 270,000 pounds per square inch. This actually teaches against the Bolt-A-Blok system use of individual, standard bolts and simple fasteners. Post-tensioning using plates, or bars, between the masonry units is a totally new way of combining steel and concrete and is sound engineering practice.
None of the prior art teaches all the features and capabilities of the Bolt-A-Blok system. As far as known, there are no systems at the present time which fully meet the need for a unitized, post-tensioned masonry block structure as well as the Bolt-A-Blok system. It is believed that this system is made with standard parts, is built with simple tools, needs no mortar, provides a much stronger structure than mortar structures, and is ready for immediate use and occupation upon construction.
SUMMARY OF THE INVENTION
A Bolt-A-Blok system has been developed for use in constructing various types of structures. Bolt-A-Blok system is a building system that demountably couples each individual hollow cored block or brick by use of a bar and bolt system. This coupling results in stronger, faster, and cheaper construction of buildings. While the three main components—a bar, a bolt and a block—are securely connected, the means of attachment is capable of full disassembly if desired. The Bolt-A-Blok system can be accomplished by unskilled persons with a simple wrench. There is no need for water, no special tools (a simple wrench will suffice), no bracing, and the structure made by the Bolt-A-Blok system is ready for immediate use. The newly invented Bolt-A-Blok system features readily available hollow core masonry units with a fastener (bolt) and a plate.
OBJECTS, ADVANTAGES AND BENEFITS
There are many, many benefits and advantages of the Bolt-A-Blok system. There currently exist no construction systems that use readily availably parts and are so easy to perform. However, by having the unitized post tensioning technology, the structure is a far stronger unit than one built by traditional mortar-using techniques. See TABLE A for the list of advantages and benefits.
TABLE A
ADVANTAGES AND BENEFITS
ITEM
DESCRIPTION
1
Is Waterless
2
Requires no wait time to get structural strength
3
Requires no temporary support while mortar cures and gains
strength
4
Uses simple hand tools
5
Is Useful with/without footer
6
Has greater final tensile and compressive strength than
mortar construction - is much stronger
7
Is Environmental friendly - Uses less wood, hence there is
less deforestation required to support construction
8
Has a reasonable total cost - material and unskilled labor
9
Permits rapid build.
10
Can be easily disassemble and components re-used.
11
Does not require skilled labor
12
Has Global/worldwide/universal applications
13
Uses Existing, standard materials
14
Can be built on soil or standard foundation
15
Spans greater distances between vertical double blocks
16
Uses standard product available throughout the globe in all
countries
17
Is easy to learn the build concept and start building with
non-skilled workers. With this easy learning curve, it is
simple to learn and simple to use. So simple that multiple
workers may be in the same area - not “laying” block but
assembling a structure
18
Provides perfect spacing which means more attractive walls.
Blocks have perfect alignment and correct placement before
tightening
19
Reduces fire insurance and wind insurance costs
20
Uses existing modular sizes, worldwide.
21
Is an all weather construction. All kinds of weather,
rain, snow, wind, cold, hot, underwater, even in a diving
bell or caisson
22
Is a Unitized construction. If one stops or anything
interrupts the build at any point, one can resume
immediately without the former problems of mortar drying
out and the other messy problems.
23
May provide Electrical grounding through metal bars
24
Provides many additional methods to attach materials using
the joint spaces - such as through bolts, carriage bolts,
and toggle bolts for adding of bolts. There is no hole
drilling in blocks needed.
25
May build a wall by working from either side. Inside or
outside.
26
Works with one or more core block, brick, and other
building units
27
Requires less scaffolding, ladder jacks and walk boards
because the walls are immediately at full strength.
28
Permits electrical wire and cable (such as Romex ™ to go
through the intermediate spaces and may fasten external
boxes or recess in drywall, etc,
29
Can pour concrete in cores and even add vertical rebar's.
30
Can pour insulation or spray foam in cores.
31
Resists flying debris.
32
Resists Earthquake and Hurricane/tornado.
33
Is fire resistant.
34
Is not dependent on mortar strength
35
Requires no power or gasoline to build
36
Uses with standard block, worldwide
37
Is useable with other construction techniques - door and
window frames, roof and ceiling joists and trusses; metal
and asphalt/fiber/rubber ?? roofing;
38
Is useable with standard plumbing, electrical,
communications and lighting packages
39
Has the ability to construct several block layers at one
time - speeds overall construction
40
Adapts to regular interior (plaster, boars, panel, paint)
and exterior wall surfaces (siding, brick, stucco, etc)
41
Provides perfect plumb and level alignment
42
Does not require poured foundations
43
Is a Unit by unit construction
44
The simple bar and bolt is easily mass produced using
existing materials and equipment.
45
Is possible for the builder to leave out a small portion of
the foundation wall so that trucks and backhoes can easily
cross into the structure to grade, spread stone, unload
concrete or do whatever is necessary. As soon as the heavy
inside work is completed, the wall is quickly bolted into
place and is ready to go, at full strength.
46
Provides a mass is so strong, and the total weight of a
Bolt-A-Blok system building is of such significant weight,
that below ground freezing may largely only push sideways.
47
May be combined with a pre-constructed bath and/or kitchen
unit.
48
Is termite and carpenter aunt proof.
For one skilled in the art of construction of structures, especially masonry, concrete, and steel structures, it is readily understood that the features shown in the examples with this system are readily adapted to other types of construction improvements.
DESCRIPTION OF THE DRAWINGS
Figures
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the Bolt-A-Blok system that is preferred. The drawings together with the summary description given above and a detailed description given below serve to explain the principles of the Bolt-A-Blok system. It is understood, however, that the Bolt-A-Blok system is not limited to only the precise arrangements and instrumentalities shown.
FIG. 1 is a sketch of the general Bolt-A-Blok system.
FIGS. 2 A through 2 E are sketches of prior art for masonry and post tensioned structures.
FIGS. 3 A through 3 F are additional prior art depictions.
FIG. 4 are sketches of the main components for Bolt-A-Blok system, namely blocks, bars, fasteners and a wrench.
FIGS. 5 including 5 A and 5 B are Bolt-A-Blok systems that show the specific parts and characteristics of the system.
FIGS. 6 A through 6 G provide details of the Bolt-A-Blok system with detailed sketches and photographs of prototype structures.
FIGS. 7 A through 7 C show the details of the Bolt-A-Blok system and several of the features that may accompany the system.
FIGS. 8A through 8 D are Photograph of a method to securely attach a roof structure to the Bolt-A-Blok system wall.
FIGS. 9 A through 9 E show sketches of possible structures made by the Bolt-A-Blok system.
FIGS. 10 A through 10 G provide photographs of attachment devices which are examples shown with the Bolt-A-Blok system prototype wall.
FIGS. 11 A through 11 M show sketches of bars and attachments for the Bolt-A-Blok system.
FIGS. 12 A through 12 D show sketches of a possible deck structures made by the Bolt-A-Blok system.
FIGS. 13 A through 13 D show photographs of tools used in the original prototype of Bolt-A-Blok system.
FIGS. 14 A through 14 E show sketches of typical hollow core masonry blocks and bricks useful when utilized with the Bolt-A-Blok system.
FIGS. 15 A through 15 C show photographs of a construction process using the Bolt-A-Blok system.
REFERENCE NUMERALS
The following list refers to the drawings:
31
general assembly of the Bolt A Blok - stacked
soldier configuration
31A
general assembly of the Bolt A Blok - stacked
running or offset configuration
32
prior art special block and through rods
34
prior art wood truss on block system
35
prior art rebar in block system
36
prior art post tension cables in concrete
37
typical scaffolding and wall build for “mortar”
masonry systems
38
typical temporary bracing for water and mortar
systems
39
typical mortar and block wall cross section
40
typical mortar and block wall corner
41
typical mortar and block wall section
42
typical mortar and block window and door lintels
43
fastener (bolt)
44
bar
45
tool (wrench)
46
hollow core block - typical
46A
hollow core block - stacked soldier configuration
46B
hollow core block - stacked running or offset
configuration
47
starter fastener
48
base means device (foundation, board, plate, etc.)
49
masonry block cavity
49A
space between adjacent block (46)
50
clear aperture through bar (44)
51
threaded aperture through bar (44)
52
prototype stacked bolt a blok system
53
bar and bolt system with blocks removed
54
prototype wall assembly
55
extended bar
56
beam on extended bar
57
insulation matter between block (46)
58
siding and insulation panel (interior or exterior)
59
pipe interior to block cavity (49)
60
top plate for truss support
61
roof joist/truss system
62
plastic sheet vinyl such as (Visqueen ™ or Tyvek ™)
63
furring strip for mounting panels, gyp board, etc.
64
extended tie rod or bar
65
means to attach (truss to wall) such as a band
clamp
66
electrical wiring
67
stabilizing shim
68
door jamb
69
wall mounting fastener
70
earthwork near foundations
71
foundation concrete
72
non linear or irregular block configuration
73
radii block for curved configurations
74
general lintel application
75
door or window perimeter
76
soldier block for lintel
77
door or window aperture
78
standard two hole bar
79
“H” bar for joining block
80
“Double H” for high strength applications
81
lintel plate and connector
82
double extended bar
83
turning bar for corners and nonlinear connections
84
connector bar
85
double row bar
86
base plate bar
87
winged base plate bar - metal or non-metal
88
door frame connection configuration
89
brick bar
90
tee-handle connector or fastener
91
lateral deck configuration
92
deck support
93
deck load - people or equipment, etc.
94
hand socket driver
95
powered impact driver
96
means to manufacture through hole/aperture in bar
(44)
97
means to manufacture threads in the bar (440 to
receive the fastener (43)
98
typical hollow cavity block
99
ornamental or decorative hollow core block
100
hollow core brick
101
fasteners for brick
102
non-skilled worker assembling the system
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
The present device is construction system called a Bolt-A-Blok system 31 . This system is comprised of only a few different types of components—a hollow core block 46 , fastener (such as a through bolt) 43 , and a simple bar 44 with some additional features. The system configures the adjacent block 46 and demountably couples the blocks by means of the bolts 43 and bars 44 . This coupling results in a structure that is formed from a plurality of unitized, post tensioned blocks or bricks that collectively are far stronger than an ordinary block structure built with mortar and standard reinforcing. A person having ordinary skill in the field of construction, especially with reinforced masonry structures, appreciates the various parts that may be used to physically permit this Bolt-A-Blok system 31 to be produced and utilized. The improvement over the existing art is providing a construction system that has many advantages and benefits as stated in the previous section entitled Objects, Advantages, and Benefits.
There is shown in FIG. 1 and FIGS. 4 through 15 a complete operative embodiment of the Bolt-A-Blok system 31 . In the drawings and illustrations, note well that the FIG. 1 and FIGS. 4 through 15 demonstrate the general configuration of this invention. The preferred embodiment of the system is comprised of only a few parts as shown. Various important features of these components are delineated in FIG. 1 and FIGS. 4 through 15 of the drawings and are described below in appropriate detail for one skilled in the art to appreciate their importance and functionality to the Bolt-A-Blok system 31 .
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the Bolt-A-Blok system 31 that is preferred. The drawings together with the summary description given above and a detailed description given below serve to explain the principles of the Bolt-A-Blok system 31 . It is understood, however, that the Bolt-A-Blok system 31 is not limited to only the precise arrangements and instrumentalities shown.
FIG. 1 is a sketch of the general Bolt-A-Blok system 31 . One should note that FIGS. 2 A through 2 E are sketches of prior art for masonry and post tensioned structures. Also a person should note that FIGS. 3 A through 3 F are additional prior art depictions. These are discussed in the prior art section above. However, a knowledge of those prior configurations and building methods serve an important background for one skilled in the art to fully appreciate the unique characteristics provided by the Bolt-A-Blok system 31 . For many decades, and in fact a full century, masons and builders, architects and engineers, have had hollow masonry blocks and bricks to use. Likewise, steel bars and various fasteners have been readily available. However, no one taught or developed this unique, simple combination as an obvious extension of the construction technology.
In FIG. 4 are sketches of the main components for using and creating structures with the Bolt-A-Blok system 31 , namely blocks 46 , bars 44 , fasteners 43 and a tool 45 (such as an open ended wrench).
FIG. 5 including 5 A and 5 B are Bolt-A-Blok systems 31 and 31 A that show the specific parts and characteristics of the system. Note there is a series of typical blocks 46 stacked as a soldier configuration 46 A or stacked in a staggered/overlap configuration 46 B. In either case, the structure “extends” through the hollow cavities 49 of the blocks 46 . The system consists of a bar 44 placed at the base on top of the base means 48 (a board, a foundation, rock or firm ground, etc). The lowermost bar 44 is secured by a starter fastener 47 such as a short bolt, a spike, a concrete anchor or the like. Then the through fasteners 43 alternate locations and extend through an open aperture 50 (not shown) and are removably connected to the lower bar 44 by means of the threaded aperture 51 (not shown). A plurality of bars 44 and fasteners 43 continue to build upward with each layer or course of the masonry block 46 . On the top block 46 the last fastener is placed and the demountable coupling of the blocks 46 is complete.
FIGS. 6 A through 6 G provide details of the Bolt-A-Blok system with sketches of prototype structures. FIG. 6 A repeats the general Bolt-A-Blok system 31 for easy reference. FIG. 6 b is a top drawing that highlights the free and open aperture 50 and the threaded aperture 51 in the bar 44 . Note the placement over the block 46 in the location of the hollow cavity 49 . The bar 44 materials may be of various metals including but not limited to steels, iron, aluminum, and the like, etc. or from composite materials such as plastics, fiberglass and other rigid materials that will permit the fasteners 43 to be torqued to sufficient pressure to hold the block 46 rigidly in place. Likewise, depending on the material and process used to create the bar 44 , there are various means of producing the through aperture 50 and threaded aperture 51 such as, for example and not as a limitation, drilling, tapping, rolling, casting, etc. FIG. 6 E shows an illustration of a prototype Bolt-A-Blok system 52 . FIG. 6 D is an illustration of the bar 44 and fastener 43 system with the blocks 46 removed. FIG. 6E is an illustration of the cross section of a single cavity 49 with the bar 44 and fastener (bolt) 43 . FIGS. 6 F and G are top view illustrations of the prototype Bolt-A-Blok system 52 looking down into the cavity 49 .
FIGS. 7 A through 7 C show the details of the Bolt-A-Blok system 31 and several of the features and components that may accompany the system in a structure such as a building wall. FIG. 7 A is an illustration of the prototype wall assembly 54 . Here a base means 48 is a simple board on top of a concrete slab. The blocks 46 are in a staggered configuration but a soldier stack would also work. In between the adjacent blocks FIG. 6 A is a very small space 49 A created by the separation of blocks 46 caused by the location of the bars 44 . This space 49 A permits many features and components to be used with the Bolt-A-Blok system 31 . For example, this illustration shows insulation matter 57 in the space 49 A between the block 46 . Also, the space 49 A allows for extended bars 55 to protrude beyond the face of the block 46 . This has helpful characteristics such as permitting a beam 56 to mount in the extended bar 55 . Furring strips 63 may be placed and attached in the space 49 A to permit panels 58 and wallboard or the like to be attached to the wall 54 on the interior or exterior surface. On the uppermost course of block 46 , a top plate 60 may be installed. This will then receive a roof truss 61 or ceiling joists. Finally shown as one of the various other features a wall 54 like this permits is a layer of plastic 62 to aid in wind infiltration and heating or cooling the structure. FIG. 7 B is a close-up illustration of the wall 54 showing a better view of the furring strip 63 and the panel 58 . FIG. 7 C is a perspective illustration of the wall 54 giving a clearer view of the beam 56 and the truss 61 . Also one notes the potential for plumbing pipes 59 to be placed inside the cavity 49 . One notes the extended tie rod 64 near the base that demonstrates the ability to connect the lower portion of a wall using the Bolt-A-Blok system 31 to an adjoining structure or other portion of a foundation.
FIGS. 8A through 8 D are several illustrations from different perspectives that demonstrate a method to securely attach a roof structure 61 to the Bolt-A-Blok system 31 wall 54 . The top plate 60 rests on the upper surface of the block 46 . The roof truss or joist structure 61 is contiguous to and in contact with the top of the top late 60 . There is a means to attach 65 the truss 61 to the block 46 . Here the means 65 is a steel clamp surrounding the truss 61 and securely connecting the truss 61 . This security is accomplished by having the steel clamp 65 being interposed into the hollow cavity 49 and surrounding a secured bar 44 , thereby rigidly and removably connecting the truss 61 to the bar 44 and hence the wall 54 .
FIGS. 9 A through 9 E show sketches of possible structures made by the Bolt-A-Blok system 31 . In FIG. 9A , a wall made of blocks 46 is placed interior to an earthwork 70 and surrounded by a concrete foundation 71 . One notes the extended tie rods or bars 64 (one or more) for securing and attaching the Bolt-A-Blok system 31 wall to the foundation. In FIG. 9B a series of courses of staggered blocks 46 B is demonstrated. In FIG. 9C a non-linear or irregular shaped structure 73 is demonstrated. Here the individual blocks 72 have a radii for the curvature creation. In FIG. 9D a general lintel 74 is formed by the Bolt-A-Blok system 31 by using a series of soldier blocks 76 secured together over the door opening 77 . One may note the block 46 are staggered and surround the opening at the perimeter 75 . In FIG. 9 E a step system is shown to demonstrate how, operationally, the Bolt-A-Blok system 31 might be used to provide rigid stairs to doorways and openings 77 in a Bolt-A-Blok system 31 structure. The blocks 46 are connected by various bars 44 such as described below in FIG. 11 .
FIGS. 10 A through 10 G provide illustrations of attachment devices which are examples shown with the Bolt-A-Blok system 31 prototype wall. Most of these have been described in the paragraphs above so only additional items are explained here. In FIG. 10A an example of an electrical wire or cable 66 is shown projecting from the face of the block 46 . The wire 66 has traversed interior to the block 46 in the hollow cavity 49 and is interposed through the space 49 A. In FIG. 10C , a door jamb 68 is attached to a space 49 A by means of fasteners. In FIG. 10D shims 67 are highlighted. Even though the Bolt-A-Blok system 31 provides an extremely level and plumb system, one skilled in the art of masonry appreciates the need to have a means to correct irregularities. This is expected to be especially helpful in third world locations and in disaster relief situations where the materials may be used or somewhat damaged and will need the ability to allow for the imperfections. In FIG. 10F a wall mounting fastener 69 is shown. One skilled in the art of fasteners appreciates well the plethora of different fastener such as those shown, closed eye bolts, hooks and the like that may be utilized with the Bolt-A-Blok system 31 .
FIGS. 11 A through 11 M show sketches of bars and attachments for the Bolt-A-Blok system 31 . These bars and attachments are exemplary and not limitations of the type of accessories appropriate for the Bolt-A-Blok system 31 . The sketches include a standard two hole bar 78 ; the “H” bar for joining block 79 ; the “Double H” bar 80 for high strength applications; a lintel plate and connector 81 ; a double extended bar 82 ; a turning bar 83 for corners and nonlinear connections; a connector bar 84 ; double row bar 85 ; a base plate bar 86 ; a winged base plate bar 87 —metal or non-metal which helps align the block; door frame connection means 88 ; a smaller version bar for a brick 89 ; and a tee handled fastener 90 that in theory would not require any tools. In Table B these, the types of blocks and other accessories are further discussed.
TABLE B
ACCESSORIES
ITEM
DESCRIPTION
1
Blocks in general
Use Different type blocks - Use Bolt-A-Blok system with any
hollow cavity masonry shape, block shape, standard shape or
special shape building units. Blocks and Bricks, 4″ 6″ 8″
12″, 2 core, 3 core, etc., are typical units. Most all use
differing length bars and bolts.
2
Bolts
Use Grade 2 hex head, square, or other type heads useable
preferably with a standard or alternatively with a special
wrench with minimum tensile strength, 74,000 pounds per
square inch
Grade 5 hex head cap screw, minimum tensile strength,
120,000 pounds per square inch
3
T-Bolts
Use T bolts to be placed in the spaces. Insert the T bolt
crossbar into the core of the block, turn a quarter turn,
tighten the washer and nut against the outside of the
block. Then attach desired items to the T bolt using
another nut. The exterior end (the bolt part that sticks
out of the block) of the T bolt must have a screwdriver
slot that is exactly parallel to the T bolt crossbar of the
T bolt. The T bolt crossbar should have a height of not to
exceed 5/16″ so it will go thru the spaces in the blocks.
Bolt diameters can vary from large to small depending on
the load to be attached. Show T bolt drawing.
Use extra long thru bolts as necessary
Use carriage and toggle bolts
4
Bar Stock
Use Bar stock that can be sheared and have holes punched or
manufacture specifically with through or threaded apertures.
Threads may be tapped or manufactured into the small hole.
Bars can be Zinc Chromate or galvanized coated for military,
or whenever needed if necessary to prevent corrosion when
they not made of a non-corroding material such as plastic or
fiberglass.
Bars may be made from flat stock or from hot rolled steel.
Example of a typical bar material stock size, for a regular
bar for an eight inch block, ⅜ × 1½ × 20′
Typical weight for a regular bar for an eight inch block,
1.06 #
Bars may also be made from plastic and other metals, in all
sizes, to use with different size building unit materials.
5
Bars
Use bars made in all sizes and materials such as metal such
as steel, aluminum, rust limiting steel and iron bars,
composite materials such as plastic and fiberglass, wood, ETC
Bars for every block and material unit size.
Typical bar size, 6 15/16″ long, for a regular bar for an
eight inch concrete block.
Extended bar sizes 8″ long and up.
Extension bars for high strength attachments. Use to connect
to other walls including 45 degree connectors at corners and
diagonals.
Ledger bars Connecting bar, about 16″ × 2″ Takes the place
of two bars.
Lintel bar - may have smaller drilled holes to put down-
pointing bolts into, to attach wood header to.
2″ wide flat bar lintel. Pairs of holes about every 7 13/16
inches, as necessary for lintel length. Holes go crosswise of
bar. Typical for a regular lintel bar for an eight inch
concrete block. Some smooth bolt holes could have slightly
slotted ends, as the bar spans the opening.
Bars to change from a 12 “block to an 8” block, and to change
from other sizes to other sizes.
Connecting bars and H bars for bottom and starter rows.
Connecting bars and H bar for foundation.
Connecting bars and H bars for spanning across bottom
openings and top openings. For short lintels And for single
horizontal rows.
Turning bars for corners, right and left.
J bars for corners.
T bars for t walls.
Y bars to attach wall ties and angle ties to Bolt-A-Blok
system walls.
Cross configuration or Plus shaped bar for corners.
Recess bars for top row or any plate row.
Extension bars with hinges on them.
Military bars may be full block width but also made with
“seals” 3/16 × 1 × 15⅝, connected with 5/16 square bar
stock, welded into block size trays, 3 cross supports.
Military blast tray mortars, galvanized. Cross supports
also ⅜ diameter rods. Typical for an eight inch concrete
block.
Steel extensions bars to attach vault, prison, or heavy
doors.
Wood bar with nut insert.
Bars of plastic, and can be thicker and/or wider in size.
Galvanize or zinc-chromate plated the bars and shims.
Military bars may be galvanized.
Thicker bars, wider bars, Plastic bars, and Plated bars.
Use a plastic threaded hole in a plastic bar.
Double length bars for side by side walls.
Welded on sleeve nut on bars if smooth bottom bar needed,
such as in starting row.
Use a threaded unit made of stainless steel, steel, brass,
etc. sleeve molded, or cast, into a plastic or pressed into
a wood bar.
Use regular plastic bars, or use combination plastic bars,
or bar, along with the frames, thus combining the bars and
fills together. All in one piece.
Use two or more extra bolts in plastic frames, if desired
Dual or triple or more bolt and bar system for 12″ or larger
blocks, or 8″ blocks needing extra strength.
Smaller size bolts for small units like bricks.
Any threaded rod okay in place of bolts.
Hook bolts.
Expanding rivet bolts.
Moly and toggle bolts.
Very large bolts for use with large material units, small
bolts for small material units.
Steel and plastic bolts.
Bolts for every block and material unit size.
6
Brick ledges. - 12 inch blocks, changing to 8 inch blocks on
the next course up, create an ideal starting ledge for
brick. Extended bars also work well for starting brick
ledges.
7
Aluminum tape, which is weatherproof, can be easily applied
to the spaces. Also, ordinary duct tape could be used under
furring strips if tyvek is not used and an air seal is
desired. Duct tape is typically used on small area wall
sections.
8
Starter plates or boards
Use Anchor Spikes, generally called spikes, to every so
often secure the bottom bars to the ground. Therefore one is
securing the blocks and the entire block wall to the ground.
Spikes can be driven through the smooth hole in the bar
directly into the ground. Spikes are ⅜ diameter rods with
a one inch head on them. These spikes vary in length from 2
to 8 feet. Spikes look like oversize nails. The surface of
Spikes can be smooth or rebar configured. Spikes are useful
for landscaping as well as for securing foundations.
Lightweight channel beams. - In place of a starter board, an
inverted light weight metal channel could be used, tapped
out appropriately so that a one inch hex head cap screw
could attach each of the several bars to the channel beam.
9
Spaces
The spaces are the clear areas between the building units or
blocks. One option is to leave the spaces open. However the
spaces are very useful in attaching anything to the unit
block walls. The spaces may also be closed for decorative
purposes or closure purposes.
10
Fills
Fills are slightly oversize rectangular pieces of wood or
plastic, that, after assembling the wall, is driven into the
spaces that are located between the bars.
There is a slight taper on the long edge of the fill that is
driven into the spaces. This helps start the fill into the
space.
A fill is what most things fasten to, such as furring strips
or anything.
A fill can be any size to accommodate the building unit
sizes, spaces, and the materials to be attached.
11
Soft Fills
Soft Fills are soft materials that, after assembling the
wall, are placed into the spaces, for looks or closure
purposes. Soft fills need no glue or adhesive properties,
only enough adhesion and cohesion to hold itself in place.
Regular mortar, Thin Mortar, Caulk, Rope caulk, Drywall mud
Any trowel, caulk gun, hand, or finger applied paste.
12
Furring strips
Furring strips are strips of wood, plastic, or other kinds
of materials that are attached to the fills, usually with
stainless steel or drywall screws. Furring strips have many
purposes, but mainly decorative, closure, and attachments.
Furring strips can be plastic or wood; can be different
lengths; can be colored, grooved, and decorated with ridges
and designs.
13
Trims
Trims finish the spaces on one side of the wall. Trims are
decorative furring strips that have fills attached to them.
Trims can simply be attached by driving them into the
spaces.
Trims could have half round, oval round, or rectangular
shaped faces.
Trims could be all colors and decorated.
Trims could be different materials, wood, plastic, etc.
Trims for corners
Precut lengths
14
Seals
Seals finish the spaces on both sides of the wall. Seals are
like trims except they do not have attached fills. Seals are
two decorative furring strips that are attached to each
other with long small rods or square shapes. These rods go
through the building units or blocks within the spaces.
Seals by themselves have a ladder like appearance.
Seals can be made of plastic wood, or steel.
Seals made of plastic are for decorative and closure
purposes. Being all in one piece, seals provide for quick
wall assembly and completion.
Seals made of steel provide blast protection, and are often
galvanized.
15
Frames
Frames are bars with fills attached.
Frames are made of steel, plastic, or wood.
16
Shims
Shims are small squares of steel or plastic. Shims are put
under bars to raise and level building units. Shims are used
below the bar ends as needed. They are secured in place when
the bar is tightened.
Use two or more shims for additional thickness.
Wafers
Wafers are thin adhesive sheets placed in vertical joints
for end of block sealing, if desired.
Core materials
Expanding foam, use as insulation, termite protection, etc.
Poured concrete
Poured concrete with rebars
17
Miscellaneous
⅜ rebars, if a Bolt-A-Blok system wall is used with a
poured concrete foundation
Use Joist brackets, Truss brackets, Brick ties bolted
directly to Bolt-A-Blok system walls
18
Apply Tyvek ™, sheet poly, or other sealing membrane.
19
Provide Support stands (out rigging) for wall stands for
military and regular purposes, supporting one side or both
sides with additional buttress structures
20
Use stainless steel bands to attach the trusses to the bars
at the top of the walls. Attach to the bottom chord and/or
to the top chord, or both. Whenever possible, use stainless
steel bands to attach the trusses to the bars at the top of
any of the partition walls. Multiple bands may be used if
desired.
21
Use extended bars to:
safely and securely attach ladders to the inside or
outside of walls.
safely and securely support interior and exterior fire
escapes
safely and securely support interior and exterior
balconies.
attach conduit to walls - all directions and sizes
attach architectural embellishments, such as foam
block, wood, plastic, decorative roof elements, and
other.
attach and support bar joists.
attach lights and lighting.
attach downspouts
22
Use bolted soldier courses when long and shorter lintels are
needed, like over doors, windows, and overhead doors.
23
Use with curved blocks, typical 2 core, based on different
radii, different faces such as split, different colors, and
more. Bay windows, landscaping, turrets, silos, round piers,
decorative bollards, towers, and other structures. Round
towers are now possible with Bolt-A-Blok system. Show curved
block drawings.
24
Use stainless steel and/or fiberglass for food tanks, acid
tanks, breweries, and more.
25
Provide Door and window frames that are installed
immediately to secure the building
FIGS. 12 A through 12 D show sketches of a possible deck structures made by the Bolt-A-Blok system 31 . Simplistically, in FIG. 12 A an illustration of a simple lateral deck 91 is shown supported by some means 92 . In this example illustration the Bolt-A-Blok system 31 is used with a series of blocks 46 in a soldier formation. FIG. 12 B shows the support 92 and highlights the simple bar 44 and bolt 43 components along with the block 46 . FIG. 12 C is an illustration from a side view. FIG. 12 D is an illustration demonstrating a person or load 93 being supported by the deck 91 . One skilled in the art appreciates that a deck like this might be used for bridges, roadways, roofs, and the like. Additionally a skilled masonry or construction person appreciates the soldier layout is an example. Obviously, a staggered pattern offers additional ways to lay out a deck.
FIGS. 13 A through 13 D show illustrations of tools used in the original prototype of Bolt-A-Blok system 31 . They are self explanatory. One skilled in completing prototype build recognizes the original bars 44 having the apertures 50 and 51 being prepared with the means 96 to provide the clear aperture. Likewise a means to provide threads 97 is shown in the illustrations. Finally, various hand drivers 94 and powered drivers are shown. While these are helpful and increase productivity, the Bolt-A-Blok system 31 still only technically needs the wrench 45 to build the system once a person has the blocks 46 , the bars 44 and the fasteners 43 . Other useful tools that may aid are shown in Table C.
TABLE C
TOOLS
ITEM
DESCRIPTION
1
Open Hand wrench
2
Ratchet
3
Power or impact Wrench
4
Grout applicators
5
Tie wire pliers/cutters
6
Levels - simple hand held; Laser; Rotating Laser level that
can be moved up & down on a rod.
7
Grout Bags - Grout Bags are what are used to easily put
mortar in spaces should that be desired for the finished
look. Grout bags hold about 6 to 10 pounds of mortar and
typically have a ⅜ tip on them. Grout Bags are easy to
use. Grout Bags are used in a similar manner as if one were
icing decorations on a cake. Grout Bags cost 5 to 7 dollars
retail. Use regular mortar, post fill the spaces and rake
the spaces if desired.
8
Power caulking gun - Use power caulking gun, typically air
operated, to apply caulk in spaces, should that be desired.
9
FIGS. 14 A through 14 E show sketches of typical hollow core masonry blocks 46 , decorative blocks 99 , bricks 100 , and a chart 98 of various configurations of hollow cavity blocks. All these types of masonry units are complementary and useful when utilized with the Bolt-A-Blok system 31 .
The details mentioned here are exemplary and not limiting. Stated again and well appreciated by one skilled in the art of construction materials, all the examples of the materials may be substituted with other plastics and composite materials that have similar properties and still be within the scope and spirit of this Bolt-A-Blok system 31 . Other components specific to describing a Bolt-A-Blok system 31 may be added as a person having ordinary skill in the field of construction as being obvious from the above described embodiment.
OPERATION OF THE PREFERRED EMBODIMENT
The new Bolt-A-Blok system 31 has been described in the above embodiment. The manner of how the device operates is described below. Note well that the description above and the operation described here must be taken together to fully illustrate the concept of Bolt-A-Blok system 31 .
FIGS. 15 A through 15 D show illustrations of a construction process for a prototype using the Bolt-A-Blok system 31 . In FIG. 15 A the first block 46 is placed on the base 48 and the bars 44 . A non-skilled worker 102 begins the construction process. In FIG. 15 B the build continues as a second block 46 is added. Here the worker 102 uses a power driver 95 but could easily use just a standard wrench 45 (not shown). In FIG. 15 C the worker 102 places a third block in a staggered configuration. The build continues until the desired length and height of the wall is realized. Additional workers could work directly along side and near the first worker 102 since no bracing or cure time is required. Once the structure is completed, occupancy is immediate.
There are many, many examples of how the Bolt-A-Blok system 31 may work in different structures. The following Table D is offered as exemplary and not limiting as to how this unique Bolt-A-Blok system 31 can be used.
TABLE D
EXAMPLES OF USES
ITEM
DESCRIPTION
1
All general construction.
Building Walls, fences, and construction partitions
Foundations
Piers under floors and bridges
Fireplaces and Flues
Retaining Walls
Decorative Panels - straight or curved
Vertical, horizontal, flat and curved wall
Self supporting columns
Use Bolt-A-Blok system for constructing partition walls
Construct segments that can be pre-assembled to any size or
shape. Then set in place with a crane, especially in areas
where it is not safe to lay building units in a regular
manner, such as atop buildings
Use with all standard lintels.
Roof deck
Steps for entry ways and multi-level buildings
Assemble Bolt-A-Blok system walls in any configuration,
silos, piers, boxes, walls, ell-walls, t-walls, u-shape
walls, and square walls
2
Bridge, levy and highway
Levy/Dams Repair broken levies, make new levies, piers. Box
shape, solid shape, U-shape, could nest larger and larger
square piers or rectangle piers. Strengthen existing levies
by putting Bolt-A-Blok system made piers in front of
existing walls. Re-enforcement can be positioned under
water and need not show. Pre make and drop long units in
place for levy control. Pull out with cable.
Bridge Structures Breakwater forms. Ultra strong forms for
pouring concrete into. Bridge forms and piers.
3
Disaster and terrorism prevent/relief
Entrance Barriers - Such as Gates and vehicle control
points
Safe room, Safe or Vault - easy builds in high rise
structures
All structures that require more fire resistant, wind
resistant, and attack resistant buildings.
Military use for blast protection, quick guard houses,
quick prisons
Quick construction in third world countries, disaster
areas, anywhere.
Use Bolt-A-Blok system for rapidly replacing buildings in
disaster areas
Wind and water resistant - Hurricane, Tornado Tsunami
resistant
Anti-terror barricades at public buildings
Earthquake resistant
4
Other
Store and garden commercial display units
Tank walls - such as Swimming pools, fire water tanks,
waste water tanks
Mobile and/or Manufactured home Building skirts
Sound-proof or noise attenuation walls and structures
Paint and hazardous material containment structures
Desert application, below freezing applications, below
water applications, mines. Use in caissons, for underwater
construction.
Surveyor monuments, mail box posts. bases for equipment
such as propane tanks and air conditioning units, wing
walls, retaining walls, motels, fire walls, storage unit
buildings, schools.
With this description of the detailed parts and operation it is to be understood that the Bolt-A-Blok system 31 is not to be limited to the disclosed embodiment. The features of the Bolt-A-Blok system 31 are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the description. | A mortarless masonry structure comprising a plurality of regular masonry blocks and/or bricks connected to each other by a plurality of metal bars and a plurality of standard metal threaded fasteners thereby forming a post tensioned structure. Preferably, the blocks are operatively connected to each other as a structure by simple mechanical tools. Each interconnection results in a unitized post tensioned member that, when interconnected to the adjacent members, forms a comparatively higher strength structure than systems made of mortar and reinforced mortar. The method used to create this structure is a simple, waterless, mortarless interconnection process that is completed by a series of simple individual steps of fastening the blocks and bars into a strong and durable structure. Once connected the structure is strong and durable. If desired, the structure may be disassembled and the components re-used. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The following applications contain subject matter related to the present application and are assigned to the assignee of the present application: co-filed applications with Ser. Nos_______ and_______.
GOVERNMENT CONTRACT
[0002] This invention was made with Government support under Defense Applied Research Projects Agency contract number DABT63-97-C-0018. The Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
[0003] Without limiting the scope of the invention, its background is described in connection with land mine detection, as an example.
[0004] Spectrophotometers analyze the absorption of light through a material to determine the composition of the material. They may be used to measure many different properties of the material. One of the properties that may be measured is the presence of various chemicals within the structure of the material. This technology may be adapted to detect the presence of explosives within an area.
[0005] Anti-personnel mines, commonly called land mines, cause severe injuries and casualties to thousands of civilians and military troops around the world each year. There are over 120 million land mines currently deployed in over 60 countries around the world. Each year, over 2 million new land mines are laid, while only about 100,000 mines are cleared.
[0006] These mines are typically deployed randomly within a strategic area and may be buried or camouflaged so they are invisible to a casual observer. Mines may instantly and indiscriminately claim unsuspecting victims who step or drive on the mine's triggering mechanism. The clandestine and indiscriminate nature of land mines make them a particularly dangerous weapon for anyone in close proximity to the mine.
[0007] Mines contain an explosive, which rapidly accelerates shrapnel or other projectiles when activated. Many mines contain trinitrotolulene (TNT), which is a common explosive compound. TNT and other explosives are polynitroaromatic compounds that emit a vapor. This emitted vapor may be useful to detect mines and other explosives.
[0008] Current detection methods range from high-tech electronic (ground penetrating radar, infra-red, magnetic resonance imaging) to biological detection schemes (dog sniffers and insects or bacteria) to simple brute force detonation methods (flails, rollers and plows) and the use of hand-held mechanical prodders. Most of these methods are very slow and/or expensive and suffer from a high false alarm rate. Mines usually do not possess self-destroying mechanisms and due to their long active time jeopardize the lives of millions of people. Furthermore, mines are difficult to find with commercial metal detectors, because their metal content is very low and in some cases even zero.
SUMMARY OF THE INVENTION
[0009] Therefore, a system that detects mines having little or no metallic content is now needed; providing enhanced design performance and accuracy while overcoming the aforementioned limitations of conventional methods.
[0010] Generally, and in one form of the invention, a spectrophotometer transducer includes a chemically sensitive wave-guiding thin film coupled to a light detector and adapted to respond to light transmitted through the wave-guiding thin film. Vapors reacting with the wave-guiding thin film alter the transmission of light through the wave-guiding thin film. The light detector recognizes changes in the transmitted light to identify the vapor that reacted with the wave-guiding thin film.
[0011] In one embodiment of the present invention, the spectrophotometer transducer has a wave-guiding thin film that is self-supporting.
[0012] In another embodiment of the present invention, the wave-guiding thin film has a reflective region to improve light transmission.
[0013] In yet another embodiment of the present invention, the spectrophotometer transducer has a light source to direct light through the wave-guiding thin film.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
[0015] [0015]FIG. 1 is a schematic of a vapor detector;
[0016] [0016]FIG. 2 is a schematic of a vapor detector having a focused light source;
[0017] [0017]FIG. 3 is a schematic of a multiple vapor detector;
[0018] [0018]FIG. 3 a is a schematic of a multiple vapor detector;
[0019] [0019]FIG. 4 is a schematic of a radiation detector; and
[0020] [0020]FIG. 5 is an illustrative embodiment of a vapor detector being used in a mine field.
DETAILED DESCRIPTION OF THE INVENTION
[0021] While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that may be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention.
[0022] For purposes of illustration, a vapor detector that uses a polymer waveguide sensitive to polynitroaromatic compounds is provided. The principles and applications of the present invention are not limited only to detecting explosives; being applicable to detection of radiation, a variety of vapors from many different substances or both, or contaminants in liquids or solutions.
[0023] Referring now to FIG. 1, a schematic representative of a vapor detector 5 is shown. A waveguide 10 may be formed from a variety of polymer compounds, such as polyvinylchloride (PVC), for example, that are suitable for producing an optically clear structure. The waveguide 10 is impregnated or infused with a chemical, Jeffamine T-403 (developed by TEXACO) for example, that reacts with vapor from the compound to be detected.
[0024] In this specific example, Jeffamine also acts as a plasticizer for the PVC compound. Inherent rigidity in the PVC compound allows the waveguide 10 to be self-supporting. A self-supporting waveguide 10 simplifies production and reduces associated costs of the device. The waveguide 10 , alternatively, may be deposited on a substrate (shown in FIG. 2).
[0025] For example, in operation, the vapor detector 5 may be used as follows. Many land mines contain TNT, which is a polynitroaromatic compound. Jeffamine T-403 reacts with TNT vapor thereby altering the light absorbent properties of the waveguide 10 . Other chemicals may be mixed with the polymer of the waveguide 10 to allow the vapor detector 5 to detect other compounds. The vapor detector 5 may also incorporate several waveguides 10 to detect multiple compounds at a single location.
[0026] A light source 12 may be used to emit light 14 into waveguide 10 . The light source 12 may be an incandescent lamp, an LED, a laser or any other light producing device known in the art. Vapor 16 that has reacted with chemicals within waveguide 10 absorbs some of the light 14 . The remainder of light 14 passes through waveguide 10 into a light detector 18 .
[0027] Light detector 18 analyzes the characteristics of the light 14 that is transmitted through the waveguide 10 , which has been exposed to vapor 16 , to identify the compound that emitted vapor 16 . Light detector 18 may be a semi-conductor photo-detector, a photo-multiplier tube, a bolometer or other heat or light-sensitive detector known in the art.
[0028] Now referring to FIG. 2, an alternative embodiment of the invention is illustrated. Light 14 from light source 12 may be focused with one or more lenses 20 to obtain a more accurate transmission of light 14 through waveguide 10 . A light block 22 may be used to direct light 14 into waveguide 10 and eliminate any stray light from sources other than the intended light source 12 . A reflective region 23 may be included on the waveguide 10 to further enhance the intensity of transmitted light 14 . The reflective region 23 may be made from polished metal or any other suitable reflective material.
[0029] Another embodiment of the invention is illustrated in FIG. 3. A beam splitter 24 may be used to create multiple beams of light 14 from a single light source 12 . These multiple beams of light 14 may be directed into multiple different waveguides 10 by lenses 20 and light blocks 22 . The light 14 is transmitted through the waveguides 10 into multiple light detectors 18 . Each waveguide 10 may be compounded with a different chemical to detect a unique compound. A vapor detector 5 with multiple, individually configured waveguides 10 could detect the presence of several different compounds located in a single area.
[0030] Another embodiment of the invention is illustrated in FIG. 3 a . Multiple beams of light 14 may be directed into multiple different waveguides 10 by multiple light sources 12 . Multiple beams of light 14 are transmitted through the waveguides 10 into multiple light detectors 18 . Each waveguide 10 may be compounded with a different chemical to detect a unique compound. Each light source 12 may emit a different wavelength of light, which is also designed to detect a unique compound. Alternatively, as indicated by the dotted lines, one embodiment of the invention may have a single waveguide 10 .
[0031] Now referring to FIG. 4, a radiation detector 6 may contain waveguide 10 , which may contain a chemical that emits light when exposed to radiation. Radioactive particle 26 impinges waveguide 10 and causes a reaction with a scintillating chemical in the waveguide 10 that produces light 14 . The light 14 is transmitted through waveguide 10 and into light detector 18 . Light detector 18 analyzes the characteristics of the light 14 that is transmitted through the waveguide 10 , and signals the presence of radiation within the area.
[0032] The source radiation must be converted into visible light prior to its detection by light detector 18 . This is accomplished by a scintillation chemical compounded in the waveguide 10 . A scintillation chemical is a material that emits optical photons in response to ionizing radiation. Optical photons are photons with energies corresponding to wavelengths between 3,000 and 8,000 angstroms. Thus, the scintillation compound converts source radiation energy from radioactive particle 26 into visible light energy, which may then be detected by the light detector 18 .
[0033] Examples of scintillation layer material for this application may include: GdO 2 S 2 , Csl, Csl:TI, BaSO 4 , MgSO 4 , SrSO 4 , Na 2 SO 4 CaSO 4 , BeO, LiF, CaF 2 , etc. A more inclusive list of such materials is presented in U.S. Pat. No. 5,418,377, which is incorporated herein by reference. Commercial scintillation layers may contain one or more of these materials.
[0034] Referring now to FIG. 5, the vapor detector 5 is shown in use in an area that contains one or more land mines 28 . The vapor detector 5 is enclosed in a robust housing 30 , which protects the vapor detector 5 from hostile environmental conditions such as rain, snow, sunlight and even wild animals. The housing 30 may be designed to shockproof the vapor detector 5 for deployment by airplane or parachute. The housing 30 may also use a self-righting design that ensures proper vapor detector 5 orientation if the vapor detector 5 is deployed by aircraft.
[0035] Land mine 28 contains an explosive that emits vapor 16 , which emanates into vents 32 in the housing 30 and exposes vapor detector 5 . Vapor 16 reacts with chemicals within waveguide 10 . Light 14 transmitted through waveguide 10 is partially absorbed by the reactants and is detected by light detector 18 . Light detector 18 signals the presence of land mine 28 in the area.
[0036] The housing 30 may also be fitted with a fan 34 . The fan 34 operates to increase air flow from the surrounding area across the waveguide 10 . The fan 34 decreases the time necessary for the vapor detector 5 to detect vapor 16 in an area. The fan 34 also increases the sensitivity and range of the vapor detector 5 by exposing the waveguide 10 to a larger volume of air and vapor 16 within the area.
[0037] The housing 30 also contains a power supply for the circuitry of the vapor detector 5 and the fan 34 . The power supply may be a battery, solar power or a combination of battery and solar power.
[0038] While this invention has been described in reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the appended claims encompass any such modifications or embodiments. | A spectrophotometer transducer is disclosed that includes a chemically sensitive wave-guiding thin film and a light detector coupled to the wave-guiding thin film. The light detector is adapted to respond to light transmitted through the wave-guiding thin film. Vapors reacting with the wave-guiding thin film reflect light transmitted through the wave-guiding thin film. The light detector recognizes changes in the transmitted light to identify the vapor that reacted with the wave-guiding thin film. | 5 |
FIELD OF THE INVENTION
The present invention relates to use of rupatadine in the manufacture of pharmaceutical composition for treating chronic obstructive pulmonary disease.
PRIOR ARTS
Chronic obstructive pulmonary disease (COPD) is a disease characterized by airflow limitation. It is usually in progressive course and cannot be totally converted, which is mostly related to abnormal inflammatory response of lung to harmful particle or gas, with the features like breath airflow decline and lung emptying tardiness. The clinical features of COPD include asthma, cough and expectoration accompanied by chronic airway obstruction and lung over-expansion. During the attack, chronic bronchitis and emphysema happen at the same time. Airway remolding of COPD may cause the functional change of airway, including successive inconvertible narrow of airway and the over-secretion of mucus. Mainly caused by smoking, COPD has relatively high morbidity and lethal rate while the present therapeutic effects are very limited. The statistics of WHO indicates that COPD was the disease with the sixth highest lethal rate in 1990 and will be the third in 2020 in anticipation.
Smoking is a primary factor leading COPD, the majority of COPD patients have long smoking experiences, and age is another important factor leading COPD. The paroxysm of COPD is of a long period and has unobvious signs. Usually, the acute attack of bronchitis is not diagnosed as COPD, and clinical patients will have different features of disease. As a result, it is difficult to make accurate diagnose of COPD in the early phase, and most patients will not seek for medical help until their lung functions decrease or have other symptoms such as breath difficulty and successive cough and expectoration. Thus, the diagnose of COPD is usually made in the middle or severe phase. As COPD is usually accompanied by emphysema and chronic bronchitis, the therapy becomes more difficult. The present clinical medicaments belong to conservative therapy which cannot make pathologic changes fundamentally.
Rupatadine, CAS number 158876-82-5 has a molecular formula as C 26 H 26 ClN 3 , molecular weight as 415.958, a protein combination rate as 98-99%, and a half-life period as 5.9 hours. Its structure is shown as formula I.
Rupatadine is a new anti-allergy medicament produced by Uriach, a Spanish pharmaceutical company, and came into the market in Spain for the first time on Mar. 15, 2003 for treating seasonal and perennial anaphylactic rhinitis. The commercial name is Rupafin and Dupafin and dosage is 10 mg once a day.
Rupatadine has a bi-function of anti-histamine and anti-platelet activating factor (PAF). Researches show that allergy and inflammatory diseases are multi-factor complex process generated by the production and release of various different mediators. Histamine is the most inflammatory mediators found at the early allergy phase and when the symptoms of this kind of diseases appear, existing in mastocyte and basophilic granulocyte. The mastocyte and basophilic granulocyte activated by allergen will produce and release histamine, which can promote the shrink of smooth muscle, the expansion of blood vessel, enhance the permeability of blood capillary as well as the secretion of mucosal glands, and induce type I hypersensitivity. Therein, the symptoms of sneezing, rhinocnesmus, tearing, nasal discharge are mostly induced by histamine H1 receptors. PAF is another important inflammatory mediators of airway inflammation. Similarly to histamine, PAF can cause shrink of bronchus and enhance the permeability of blood vessels, which leads to nasal discharge and nasal congestion. Meanwhile, PAF can also enhance the sensitivity of bronchus, which is the main inducing factor of asthma. It is indicated by researches that 66% of asthma is induced by rhinitis, and nasal diseases are the beginning of weasand diseases such as asthma, chronic obstructive pulmonary disease, and bronchiectasia etc. Latest research of PAF functional mechanism shows that PAF acts on airway indirectly leading to obstruction and high sensitivity hyperfunction and further inducing the release of leukotrienes. PAF is complementary to histamine in general. Histamine is an early response media released by containers of mastocytes, while PAF is de novo synthesized. However, currently, the clinical anti-allergy medicament has only anti-histamine activity rather than anti-PAF activity. It is obvious that a medicament with both anti-histamine and anti-PAF activity will have better clinical performance than that with only one. Rupatadine is the only commercial available anti-allergy medicament with both anti-histamine and anti-PAF activity presently, so it has promising prospective in clinical application.
Rupatadine has good affinity to histamine H1 receptors. Induced by the anti-histamine activity of rupatadine, the ileum of Guinea pig can be shrinked in vitro. According to this, the comparison of rupatadine and the first and second generation of anti-histamine medicaments in the prior art shows: rupatadine has stronger anti-histamine activity than terfenadine, loratadine, cetirizine, hydroxyzine, diphenhydramine. Herein, the anti-histamine activity of rupatadine (IC50=0.0035 μm) is 80 times stronger than that of loratadine (IC50=0.29 μm), and 100 times stronger than that of other anti-histamine medicaments. The anti-histamine activity of rupatadine is the same as desloratadine in vitro. In addition, experiments in vitro show some metabolin of rupatadine also have anti-histamine activity, and the anti-histamine activity of some specific metabolin is at the same level with desloratadine, the metabolin of loratadine.
In prior art, the researches of anti-PAF activity of rupatadine is conducted on models of several animals such as mouse, rabbit, Guinea pig and dog both in vivo and in vitro. In the experiment of platelet aggregation induced by anti-PAF activity, IC50 of rupatadine in platelet rich plasma, serum of rabbits and whole blood of dogs are 2.9, 0.2 and 0.29 μm respectively. This experiment shows that rupatadine has good PAF antagonism. However, the experiment of platelet aggregation induced by PAF antagonism in platelet-rich plasma of rabbits shows that IC50 of the second generation of anti-histamine medicaments, such as loratadine, cetirizine, mizolastine, fexofenadine are 7142, 7200, 7200 and 7200 μm respectively, suggesting little or very weak PAF antagonism. In the model of blister induced by subcutaneous injecting histamine or PAF in dogs, rupatadine can effectively inhibit blister (0.3-10 mg/kg, oral administration), while loratadine and cetirizine can only inhibit the blister induced by histamine. The best potency will appear in 4 hours after intake of rupatadine and the effect will last for 24 hours, suggesting rupatadine is a sustained-release medicament. Rupatadine can inhibit conjunctivitis induced by histamine or PAF of Guinea pig, while loratadine cannot inhibit the conjunctivitis induced by PAF. If rupatadine is applied to eye drops, the therapy effect will be 10 times better than that of loratadine.
In addition, compared to other anti-histamine medicaments, rupaladine shows broader-spectrum pharmacological activity in non-histamine-dependent pharmacological models. It can inhibit the degranulation of mastocytes as well as the chemotaxis of eosinophil. The degranulation of mastocytes plays an important role in allergy process, especially in the early phase, while eosinophil is the key response cell in the later phase of allergy. The oral administration of rupatadine is absorbed fast and with a half-life period of 12 hours, in general, the blood concentration will reach the peak after intaking tablet in 1 hour, while will reach the peak after intaking the capsule in 1.5 hours. Rupatadine metabolizes through liver and gall primarily. Some of the metabolin also have anti-histamine activity, which may make rupatadine have systemic and long-effective anti-allergy activity.
The II and III phases of clinical experiments of rupatadine were done in 10 clinical experiment centers in Spain, France, South Africa, United Kingdom and more than 2900 patients, aged from 12 to 82 and suffering seasonal or perennial allergic rhinitis, took participate into the experiments. The safety and effectiveness of rupatadine have been affirmed through experiments. Experiments evaluating the safety and effectiveness in two weeks with feeding rupatadine 2.5 mg, 5 mg, 10 mg, 20 mg per day were carried out relative to placebo. The results show that rupatadine can alleviate the symptoms more effectively than placebo, among them, feeding 20 mg per day got the highest score in symptom alleviation and 10 mg per day had the best comprehensive therapy effects. Another experiment evaluating the safety and effectiveness of rupatadine with feeding 10 mg and 20 mg per day for patients suffering seasonal allergic rhinitis relative to placebo: the patients are divided into three groups, i.e. 10 mg group. 20 mg group and placebo group, at random. The medicaments were taken every day for two weeks, the results show that nasal and optical symptoms for seasonal allergic rhinitis patients were much more alleviated by intaking of 10 mg and 20 mg per day rupatadine than placebo. Hereinto, intaking 10 mg per day has no significant difference to 20 mg per day, while intaking 20 mg per day will have a better alleviation trend in a week.
Further, comparing rupatadine to other anti-histamine medicaments, it is shown that 10 mg per day rupatadine has similar effects with the same dosage of cetirizine, while the former has little side effects on central nervous system. And rupatadine can alleviate the symptoms of seasonal allergic rhinitis more than loratadine and ebastine under the same dosage.
In a random, double-blind, placebo controlled, multicenter parallelled intake test, comparing intaking 10 mg or 20 mg per day rupatadine, 10 mg per day loratadine or placebo for two weeks for treating patients suffering seasonal allergic rhinitis, the results showed that intaking 10 mg or 20 mg per day rupatadine had better effects than intaking 10 mg per day loratadine and specially in alleviating symptoms of sneezing and rhinocnesmus.
In another random, double-blind, placebo controlled, multicenter parallelled intake test, 250 patients with seasonal allergic rhinitis took 10 mg rupatadine, 10 mg ebastine or placebo daily for 2 weeks. The results showed that rupatadine had better therapeutic effects than ebastine, especially in alleviating sneezing and tearing, the former was far better than the latter.
Rupatadine is highly selective to peripheral nervous receptors H1 and has strong and long-lasting activity, while its affinity to central nervous system is little and has little permeability of blood brain barrier, so there is no side effect of calm. The experiments showed that even if 1000 mg/Kg and 10 mg/Kg of rupatadine were given to a mouse and macaque respectively, the period of QTC and QRS would not be extended, nor would it lead to arrhythmia in rats, Guinea pigs and dogs. Also 3-hydroxy desloratadine, the main metabolin of rupatadine in vivo does not affect cardiomotility, perhaps due to the little concentration of rupatadine in heart and it is usually difficult to be detected. As a result, rupatadine will not cause cardiotoxicity and no accumulation reaction will occur after successive intaking. It also has no effect on alcohol, a wide range of safe dosage and good tolerance.
The latest research shows that rupatadine has good ability against pulmonary fibrosis, and it also can convert the pulmonary fibrosis induced by Bleomycin, declining the lethal rate caused by pulmonary fibrosis induced by Bleomycin of mammals. Rupatadine can decline the inflammation and EMT in tissues of pulmonary fibrosis, and also the deposition of collagen, enhance the lung function.
Distinguished from pulmonary fibrosis, COPD has its own unique causes and process. So the medicaments against pulmonary fibrosis may not be used in treating COPD. Although smoking and aging are the most common causes for COPD, there are still proofs that non-smoking and non-elderly people can also suffer COPD. So the nosogenesis of COPD is so complicated that basic pulmonary inflammation theory or other academic theories in present cannot cover it.
Nowadays, there still lacks effective therapy for chronic obstructive pulmonary disease, as a result, it is urgent to develop a new medicament with good therapeutic effects in alleviating or treating COPD.
CONTENT OF THE PRESENT INVENTION
The technical problem to be solved in the present invention is, regarding the lack of drugs for preventing or treating chronic obstructive pulmonary disease, to provide a new use of rupatadine. Rupatadine can be used for effectively preventing or treating chronic obstructive bronchitis, obstructive emphysema or chronic obstructive pulmonary disease.
The technical solution adopted to solve the technical problem above is that a use of rupatadine in the manufacture of pharmaceutical composition for preventing or treating chronic obstructive bronchitis, obstructive emphysema or chronic obstructive pulmonary disease.
In the present invention, the “chronic obstructive bronchitis” means chronic, non-specific inflammation of tracheal and bronchial mucosa and surrounding tissues thereof, which is clinically characterized by cough, expectoration or a chronic process accompanied by gasp and repeated attacks.
In the present invention, the “obstructive emphysema” is caused by the narrow of bronchiole resulted by chronic bronchitis or other reasons, over-gassing of far-ending air cavity of bronchioli terminales accompanied by expansion or explosion of air cavity wall, and it is usually the complication of chronic bronchitis in clinical.
In the present invention, the “chronic obstructive pulmonary disease” (COPD) is a disease characterized by the limitation of airflow. The clinical symptoms thereof include the decline of breath airflow, the tardiness of lung emptying, asthma, cough, expectoration, accompanying by the chronic obstructive of air passage and the over expansion of lung, as well as experiencing chronic obstructive bronchitis and obstructive emphysema during an attack.
In the present invention, the chronic obstructive pulmonary disease is the COPD of human beings or animals.
In the present invention, the “preventing” is to prevent or decline the occurrence of chronic obstructive bronchitis, obstructive emphysema or COPD in the presence of possible factors of chronic obstructive bronchitis, obstructive emphysema or COPD.
In the present invention, the “treating” is to alleviate the degree of chronic obstructive bronchitis, obstructive emphysema or COPD, or to cure and normalize chronic obstructive bronchitis, obstructive emphysema or COPD, or to decelerate the process of chronic obstructive bronchitis, obstructive emphysema or COPD. Specifically, rupatadine can improve the lung function effectively, recover the basic physiological structure of lung, decline the infiltration and expression of various inflammatory cells, decline the degree of inflammation and infiltration of inflammatory cells. Rupatadine plays a role in adjusting body immune balance in chronic pulmonary diseases, and balances the immune reaction between Th1 and Th2. Rupatadine can convert COPD and treat asthma, improve the lung function and convert emphysema.
In the present invention, the “rupatadine” is rupatadine or the pharmaceutical acceptable derivative thereof, including pharmaceutical acceptable salt, ester and so on.
In the present invention, the pharmaceutical composition preferably comprises rupatadine and pharmaceutical carrier.
Therein, the pharmaceutical composition more preferably comprises 0.1%-99% rupatadine and 0.1%-99% pharmaceutical carrier, the percentage is a mass percentage of each component to the total mass of the pharmaceutical composition.
Therein, rupatadine can be active ingredient individually or together with other compounds. The “active ingredient” is an active ingredient with activity in treating chronic obstructive bronchitis, obstructive emphysema or chronic obstructive pulmonary disease.
Therein, the pharmaceutical composition preferably comprises inhibitors against histamine 1-4 receptors and/or an inhibitor against PAF receptor.
Therein, the pharmaceutical carrier comprises pharmaceutical acceptable excipient, filler and diluent etc.
Therein, there is no special limitation in formulation of the pharmaceutical composition. It can be solid, semisolid or liquid, it can also be an aqueous solution, a non-aqueous solution, or a suspension. It can be a pill, a capsule, particle, an injection, or an infusion agent etc. as well. The pharmaceutical composition can be administrated orally, intravenously, intramuscularly, intradermally or hypodermically.
Dosage of the pharmaceutical composition containing rupatadine in the present invention depends on the age and state of illness of patients. The daily dosage is about 0.0001-1000 mg in general, preferably 0.01-500 mg, more preferably 0.1-200 mg. The pharmaceutical composition is given once or more than once a day.
In the process of preventing or treating COPD, the pharmaceutical composition containing rupatadine can be used alone or together with other medicaments.
Unless otherwise indicated, the reagents and raw materials used in the present invention are all commercially available.
In the present invention, the mentioned optimized conditions can be optionally combined based on the general knowledge in this field to obtain preferred embodiments.
The positive effects of the present invention are as follows: the present invention provides a new medicament-rupatadine for preventing or treating. It has significant therapeutic effects in treating chronic obstructive bronchitis, obstructive emphysema or chronic obstructive pulmonary disease with low toxicity and little side effects, and is safe in use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a contrast figure about the amount of various inflammatory cells in bronchoalveolar lavage fluid of sham-operation group, model group and rupatadine treated group of smoking-induced COPD mice in embodiment 1.
FIG. 2 is a contrast figure about the amount of various inflammatory cytokines in bronchoalveolar lavage fluid of sham-operation group, model group and rupatadine treated group of smoking-induced COPD mice in embodiment 1.
FIG. 3 shows pathological examination photos of lung tissue of sham-operation group, model group and rupatadine treated group of smoking-induced COPD mice in embodiment 1.
FIG. 4 shows pathological examination photos of lung tissue of sham-operation group, model group, positive control group and rupatadine treated group of TLR4-lacked emphysema mice in embodiment 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following examples further illustrate the present invention, but the present invention is not limited thereto.
In the following embodiments, “%” in solutions represents quality volume percent. Results of experiments are expressed in the form of average±standard error (X±SE), and examined by the parameter or non-parameter variance. After comparison, p<0.05 is regarded as having significant difference, p<0.01 is regarded as having extremely significant difference. Chi-square test is used in the statistics of pathology classification information. After comparison, p<0.05 is regarded as having significant difference, and p<0.01 is regarded as having extremely significant difference. PBS (i.e. phosphate buffer solution) used in the embodiments has a concentration of 0.1M and pH value of 7.2.
Embodiment 1
1. The Preparation of COPD Animal Model
Main agents and animals for experiments: Cigarettes used in the experiment, type 3R4F, were purchased from Tobacco Research Center, University of Kentucky, USA. C57BL/6 mice on level SPF used in the experiment (male, aged 6-8 weeks, 16-18 g) were purchased from Institute of Animal, Chinese academy of medical sciences.
Preparation of COPD animal model: C57BL/6 mice were put in a smoke box and 5 cigarettes were inhaled without filter tip each time. The ratio of smoke to air was 1:6, and the whole flow rate of gas was 150 ml/min. Smoking experiment was conducted 4 times a day, 30 minutes for each time and last for 24 weeks.
2. Treating COPD of Smoking Mice by Rupatadine
Main agents: rupatadine, produced by Zhejiang Cifu pharmaceutical limited company. It is the API of rupatadine fumarate. The content of rupatadine is more than 99%.
Therapy: grouping and feeding animal models with medicaments. The groups were as table 1:
TABLE 1
The number
Route of
Number
Group
of animals
Dosage and drug regimen
administration
Solvent
A
Sham
15
Equivalent amount of solvent,
i.g.
PBS
lasting for 4 weeks after modeling,
once a day
B
Model
20
Equivalent amount of solvent,
i.g.
PBS
lasting for 4 weeks after modeling,
once a day
C
Rupa
20
6 mg/kg rupatadine, lasting for 4
i.g.
PBS
weeks after modeling, once a day
Note:
Group A is sham-operation group (Sham). Group B is model group (Model), and group C is rupatadine treated group (Rupa).
3. Test the Amount of Inflammatory Cells in Bronchoalveolar Lavage Fluid of COPD Mice
The mice were dissected at neck and the weasand was exposed for intubation. The lavage amount of PBS was 0.8 ml and the lavage was conducted 3-5 times. The lavage solution was recycled and centrifuged at 1500 r for 10 minutes at 4° C. The supernate was recycled and kept at −20° C. for the test of cytokines.
Cells were reselected and precipitated by 1 ml 1% BSA in PBS. 10 μl resuspension solution was taken for calculating the amount of cells and the hematology analyzer was used for analysis. The results were shown in FIG. 1 , and the detailed data were shown in Table 2. It can be seen from FIG. 1 , compared with the sham-operation group, the total number of hemameba ( FIG. 1A ), monocyte ( FIG. 1B ), neutrophile granulocyte ( FIG. 1C ), lymphocyte ( FIG. 1D ), basophil ( FIG. 1E ), and eosinophils ( FIG. 1F ) in bronchoalveolar lavage fluid of smoking-induced COPD mice increased extremely remarkably. So it indicated that 6 mg/kg rupatadine treated group could remarkably reduce the amount of various inflammatory cells in bronchoalveolar lavage fluid of smoking-induced COPD mice compared to the model group.
TABLE 2
total
Neutrophile
hemameba
Monocyte
granulocyte
Lymphocyte
Basophil
Eosinophils
Group
(number/mL)
(number/mL)
(number/mL)
(number/mL)
(number/mL)
(number/mL)
Sham
3.874 * 10 6
21.731 * 10 5
8.138 * 10 5
3.767 * 10 5
2.082 * 10 4
1.979 * 10 4
Model
21.266 * 10 6
72.086 * 10 5
60.259 * 10 5
51.945 * 10 5
33.791 * 10 4
37.084 * 10 4
Rupa
13.69 * 10 6
49.504 * 10 5
33.864 * 10 5
32.694 * 10 5
24.816 * 10 4
34.692 * 10 4
4. Test the Amount of Inflammatory Cytokines in Bronchoalveolar Lavage Fluid of COPD Mice
The mice were dissected at neck and the weasand was exposed for intubation. The lavage amount of PBS was 0.8 ml and the lavage was conducted 3-5 times. The lavage solution was recycled and centrifuged at 1500 r for 10 minutes at 4° C. The supernate was recycled and kept at −20° C. for the test.
100 μl supernate was taken to conduct ELISA examination, and commercial available ELISA kit was used to test the amount of inflammatory cytokines. The results were shown in FIG. 2 , and the detailed data were shown in Table 3. It can be seen from FIG. 2 , compared with the sham-operation group, the content of IL-2 ( FIG. 2A ), IL-4 ( FIG. 2C ), IL-17 ( FIG. 2D ) increased remarkably in lungs of COPD mice. It indicated that 6 mg/Kg rupatadine treated group could reduce the content of various inflammatory cytokines in lungs of COPD mice, while rupatadine did not affect the content of IFN-γ ( FIG. 2B ), which plays an important role in tissue repair. So it was proved that rupatadine can adjust body immune reactions directionality.
TABLE 3
Group
IL-2
IFN-γ
IL-4
IL-17
Sham
8.85 pg/ml
22.17 pg/ml
18.33 pg/ml
61.63 pg/ml
Model
46.79 pg/ml
19.65 pg/ml
45.2 pg/ml
92.48 pg/ml
Rupa
6.71 pg/ml
26.28 pg/ml
6.54 pg/ml
35.53 pg/ml
5. Pathological Evaluation of Smoking-Induced COPD Mice
HE staining method is also named Hematoxylin-Eosin staining method. Hematoxylin dye liquor is alkaline, and mainly colors intranuclear chromatin and intracytoplasmic ribosome into bluish violet. Eosin is acidic dye, and mainly colors the components in cytoplasm and extracellular matrix.
The lung tissues on the right lower lobe was cut, fixed by 4 wt % paraformaldehyde and then embedded by paraffin. The largest cross-section of the paraffin embedding lung tissue was stained by HE staining method, and the result was shown in FIG. 3 . FIG. 3 showed that the area of alveoli increased remarkably in the lungs of COPD mice ( FIG. 3B ), and the far-end air cavity of terminal bronchiole was expanded, the normal lung tissue was destroyed with the occurrence of emphysema, while rupatadine could effectively recover normal structure of alveoli ( FIG. 3C ), and decrease the expansion of far-end air cavity of terminal bronchiole.
Embodiment 2
1. The Preparation of a Model with Emphysema Induced by TLR4 Mutant
Animals for experiment: C3H/HeN wild type mice on SPF level were purchased from Beijing Vitalriver Experimental Animals Limited Company. TLR4 mutant C3H/HeJ mice were purchased from Institute of model animals, Nanjing University.
Method: Fed the SPF mice and the TLR4 mutant mice in experimental animal center of Institute of pharmaceutics research, Chinese academy of medical sciences. Provide free diet under constant temperature and humidity. The mice were killed until they were 3 months old.
2. Treat Emphysema Induced by TLR4 Mutant in Mice by Rupatadine
Main agents and experimental animals: rupatadine, produced by Zhejiang Cifu pharmaceutical limited company. It was the API of rupatadine fumarate. The content of rupatadine was more than 99%. IL-17A used in positive control group was purchased from R&D Company.
Therapy: Grouping and feeding animal models with medicaments. The groups were shown in table 4:
TABLE 4
The number
Route of
Number
Group
of animals
Dosage and drug regimen
administration
Solvent
A
Sham
15
Equivalent amount of solvent,
i.g.
PBS
lasting for 4 weeks after
modeling, once a day
B
Model
20
Equivalent amount of solvent,
i.g.
PBS
lasting for 4 weeks after
modeling, once a day
C
IL-17A
20
1 g/kg IL-17A, lasting for 4 weeks
i.g.
PBS
after modeling, once a day
D
Rupa
20
6 mg/kg rupatadine, lasting for 4
i.g.
PBS
weeks after modeling, once a day
Note:
Group A is sham-operation group (Sham). Group B is model group (Model). Group C is IL-17A treated group (IL-17A), and group D is rupatadine treated group (Rupa).
3. Pathological Evaluation of Mice with Emphysema Induced by TLR4 Mutant
HE staining method is also named Hematoxylin-Eosin staining Hematoxylin dye liquor is alkaline, and mainly colors intranuclear chromatin and intracytoplasmic ribosome into bluish violet; Eosin is acidic dye, and mainly colors the components in cytoplasm and extracellular matrix.
The lung tissues on the right lower lobe was cut, fixed by 4 wt % paraformaldehyde and then embedded by paraffin. The largest cross-section of the paraffin embedding the lung tissue was stained by HE staining method, and the result was shown in FIG. 4 . FIG. 4 showed that the area of alveoli increased remarkably in mice with emphysema ( FIG. 4B ), and the far-end air cavity of terminal bronchiole was expanded, the normal lung tissue was destroyed, while positive control IL-17A ( FIG. 4C ) could effectively inhibit the further development of emphysema in mice. Rupatadine could effectively recover normal structure of alveoli ( FIG. 4D ), and decrease the expansion of far-end air cavity of terminal bronchiole.
Based on the analysis of embodiment 1 and 2, it can be concluded that rupatadine can effectively improve the pulmonary function and recover the basic physiological structure of lung in mice suffering COPD, and it can also alleviate the infiltration and expression of various inflammatory cells, and plays a role in adjusting body immune balance in chronic inflammatory pulmonary diseases, i.e. balancing immune reaction between Th1 and Th2.
Generally speaking, COPD patients in a stable phase have hyperfunctions of Th1 lymphocyte, while the balance between Th1/Th2 will shift to Th2 in an acute aggressive phase. Based on the above experiment results, it is reasonable to consider that rupatadine can resist inflammation and asthma, and adjust immune balance as well as convert COPD. As a result, rupatadine used in treating COPD will improve lung function, convert emphysema as well as alleviate the degree of inflammation and infiltration of various inflammatory cells. | Disclosed is the use of rupatadine in the manufacture of pharmaceutical composition for preventing or treating chronic obstructive bronchitis, obstructive emphysema or chronic obstructive pulmonary disease. The new medicament, i.e. rupatadine, for treating chronic obstructive pulmonary disease is obvious in therapeutic effects, and low in toxic and side effects, and safe in use in the aspects of treating chronic obstructive bronchitis, obstructive emphysema or chronic obstructive pulmonary disease. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to a poly(3-hydroxyalkanoate) block copolymer having shape memory effects. More specifically, the present invention relates to a block copolymer comprising a 3-hydroxybutyrate block as a repeating unit and a 3-hydroxyvalerate block as a repeating unit, and optionally comprising a hydroxy acid repeating group containing 6 or more carbon atoms, whereby the copolymer has orientation-induced rubber-elasticity and temperature-sensitive shape memory effects.
BACKGROUND OF THE INVENTION
[0002] Poly(3-hydroxyalkanoates) (hereinafter, often referred to as “PHAs”) are polymers having superior mechanical properties as well as unique properties such as biodegradability and biocompatibility, and therefore a great deal of research and study has been made thereon. PHAs are generally classified into short-chain-length PHAs (SCL-PHAs), medium-chain-length PHAs (MCL-PHAs) and long-chain-length PHAs (LCL-PHAs), depending upon the number of carbon atoms of the constituting monomers thereof.
[0003] SCL-PHAs are PHAs in which the number of carbon atoms of the monomers constituting PHAs, such as 3 -hydroxybutyrate (hereinafter, often referred to as “3HB”), 3-hydroxyvalerate (hereinafter, often referred to as “3HV”) and 4-hydroxybutyrate, is not more than 5, and include, for example a poly(3-hydroxybutyrate) (PHB) homopolymer and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (hereinafter, referred to as poly(3HB-co-3HV)) copolymer. MCL-PHAs are PHAs consisting of monomers containing 6 to 12 carbon atoms such as 3-hydroxyhexanoate (3HHx), 3-hydroxyheptanoate (3HHp) and 3-hydroxyoctanoate (3HO), and include, for example homopolymers or copolymers of such monomers. Finally, LCL-PHAs are PHAs consisting of monomers containing 13 or more carbon atoms, and include, for example homopolymers or copolymers of such monomers.
[0004] These PHAs may be synthesized by chemical synthesis or biosynthesis. In particular, methods for preparing PHAs via biosynthesis using microorganisms are well known in the art. Hitherto, microorganisms including more than 90 genera are known to biosynthesize PHAs. In addition, it is also known that there are more than 150 kinds of monomers of PHAs that are prepared via biosynthesis.
[0005] PHAs exhibit various physical properties depending upon kinds and compositions of monomers. Further, due to their diversity, it is believed that there are numerous physical properties that have yet to be identified.
SUMMARY OF THE INVENTION
[0006] Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide novel physical properties of a PHA block copolymer, a method for preparing such a PHA block copolymer and use thereof.
[0007] As a result of a variety of extensive and intensive studies and experiments, the inventors of the present invention have surprisingly discovered that a PHA block copolymer having a specific composition exhibits shape memory effects. Shape memory effects are physical properties that were partially confirmed in metals and general polymers, but were not confirmed hitherto in PHAs primarily prepared via biosynthesis. In particular, it was confirmed that a certain PHA block copolymer provided herein exhibits orientation-induced rubber-elasticity in conjunction with temperature-sensitive shape memory effects and has fast shape-recovery ability. Such characteristics in conjunction with physical properties such as biodegradability and biocompatibility intrinsic to PHAs offer opportunities that enable PHAs to be utilized in a variety of applications. The present invention has been completed based on these findings. In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a PHB block copolymer having orientation-induced rubber-elasticity and temperature-sensitive shape memory effects, comprising:
[0008] a plurality of 3-hydroxybutyrate (3HB) blocks represented by Formula 1 as shown below as a repeating unit:
[0000]
[0009] wherein m is not less than 2; and
[0010] a plurality of 3-hydroxyvalerate (3HV) blocks represented by Formula 2 as shown below as a repeating unit:
[0000]
[0011] wherein n is not less than 2; and
[0012] optionally a plurality of hydroxy acid blocks containing 6 or more carbon atoms, represented by Formula 3 as shown below:
[0000]
[0013] wherein p and q are independently not less than 2.
[0014] That is, the poly(3HB-co-3HV) block copolymer in accordance with the present invention can impart a temporary shape with rubber-elasticity and exerts temperature-sensitive shape memory effects. Herein, although the block copolymer in accordance with the present invention also encompasses a block copolymer in the form of poly(3HB-co-3HV-co-HA), poly(3HB-co-3HV) will be representatively illustrated hereinafter. It is speculated that action mechanisms for such characteristics are caused by induced orientation of soft segments and hard segments, which are formed by a plurality of 3HB blocks and 3HV blocks contained in one polymer molecule, resulting from application of external force and changes in temperatures. Hard segments prevent permanent deformation of the shaped materials. Chain entanglement and physical crosslinkers such as blocks of molecules exhibiting higher glass transition temperatures and melting points serve as hard segments. Soft segments are blocks of molecules having lower glass transition temperatures, and can induce deformation, thus making it possible to provide reversible setting and releasing properties.
[0015] Based on such unique physical properties, the poly(3HB-co-3HV) block copolymer in accordance with the present invention can be heated to a temperature ranging from a melting point to thermal decomposition temperature thereof, thus making it possible to prepare a permanently deformed particular shape. In addition, it is possible to obtain a shaped material having a temporary shape by applying constant external force to the permanently shaped material, for example at room temperature for a predetermined period of time. Such a temporarily shaped material is rapidly recovered to its original state of the permanently shaped material when it is heated to a temperature ranging from a glass transition temperature to melting point thereof.
[0016] In particular, shape memory effects are completely novel physical properties which were not known hitherto in PHAs and thus are highly significant in that applicability of PHAs to various fields can be greatly extended. Further, according to experiments of the present inventors, it was confirmed that a recovery rate in terms of shape memory effects is very fast, and such a shape recovery rate is higher than those of other general synthetic polymers.
[0017] Further, in most cases of conventional shape memory polymers, in order to set shapes thereof, a sample is heated to a temperature above a glass transition temperature of the soft segment, followed by deformation, and the temperature of the sample is then lowered below the glass transition temperature while keeping a deformed state, thereby maintaining a temporary shape thereof. Whereas, even when it is stretched at a temperature below the glass transition temperature, the shape memory polymer in accordance with the present invention can maintain a deformed shape by means of orientation induced crystallization and thereby can provide convenience in terms of processing.
[0018] The numbers of 3HB blocks and 3HV blocks present in one polymer molecule are not particularly limited so long as the numbers of blocks are within the range such that orientation-induced rubber-elasticity and shape memory effects are exerted while permitting to take a form of a block copolymer. For example, a content of 3HV in the total monomers of the copolymer is preferably within a range of 10 to 90 mol %, more preferably 20 to 80 mol %, and particularly preferably 30 to 70 mol %.
[0019] A molecular weight of the poly(3HB-co-3HV) block copolymer in accordance with the present invention is approximately in a range of several tens of thousands to several millions, preferably several hundreds of thousands, and more specifically in a range of 300,000 to 600,000.
[0020] If necessary, the PHA block copolymer in accordance with the present invention, as described above, may further comprise not more than 70 mol %, preferably not more than 50 mol %, and more preferably not more than 30 mol % of the hydroxy alkanoate (HA) block of Formula 3 as shown below, based on the total polymer:
[0000]
[0021] wherein p and q are independently not less than 2.
[0022] In accordance with another aspect of the present invention, there is provided a method for preparing the above-mentioned poly(3HB-co-3HV) block copolymer having shape memory effects. The poly(3HB-co-3HV) block copolymer can be prepared chemical synthesis, or biosynthesis using microorganisms. The latter is particularly preferred. As to biosynthesis of the poly(3HB-co-3HV) block copolymer using microorganisms, the inventors of the present invention have provided a Pseudomonas sp. HJ-2 strain (hereinafter, referred to as “HJ-2”) in Korean Patent Publication Laid-open No. 1999-0080695, which was deposited with the Korean Collection for Type Cultures (KCTC) affiliated with the Korean Research Institute of Bioscience and Biotechnology (KRIBB, Korea), under Accession Number KCTC 0406 BP. When it is cultured in a culture medium containing saturated and/or unsaturated carboxylic acids and/or carbohydrates such as glucose, starch or the like, the HJ-2 strain produces PHA copolymers containing various monomers. Therefore, although the disclosure of Korean Patent Publication Laid-open No. 1999-0080695 is incorporated by reference herein in its entirety, it should be construed that utilization of any other strains capable of synthesizing the shape-memory poly(3HB-co-3HV) block copolymer in accordance with the present invention other than the HJ-2 strain falls within the scope of the present invention.
[0023] In one preferred embodiment, it is possible to prepare the shape-memory poly(3HB-co-3HV) block copolymer in accordance with the present invention in a relatively high concentration by culturing the HJ-2 strain with supply of heptanoic acid as a sole carbon source.
[0024] The HJ-2 strain harbors both a short-chain-length PHA synthetic gene and a long-chain-length PHA synthetic gene, and the shape-memory poly(3HB-co-3HV) block copolymer can be biosynthesized by the short-chain-length PHA synthetic gene. Therefore, the present invention provides the short-chain-length PHA synthetic gene of the HJ-2 strain that is capable of biosynthesizing the poly(3HB-co-3HV) block copolymer having shape-memory effects.
[0025] Preferably, the above short-chain-length PHA synthetic gene is a gene including a gene having a sequence as set forth in SEQ. ID. NO: 12, a gene having a sequence as set forth in SEQ. ID. NO: 13, and/or a gene having a sequence as set forth in SEQ. ID. NO: 14.
[0026] Further, the shape-memory poly(3HB-co-3HV) block copolymer in accordance with the present invention may be synthesized by culturing a microorganism transformed with the short-chain-length PHA synthetic gene of the HJ-2 strain or by cell-free protein synthesis using the above-mentioned gene.
[0027] In accordance with a further aspect of the present invention, there is provided a method for application of a shape-memory poly(3HB-co-3HV) block copolymer to various uses.
[0028] In accordance with yet another aspect of the present invention, there is provided a blending or composite comprising a shape-memory poly(3HB-co-3HV) or poly(3HB-co-3HV-co-HA) block copolymer and a method for application thereof to various uses.
[0029] Surprisingly, it was further confirmed that a blending or composite, in which the shape-memory poly(3HB-co-3HV) or poly(3HB-co-3HV-co-HA) block copolymer is mixed with a general-purpose polymer resin such as polyvinylchloride (PVC), also exhibits shape memory effects. Therefore, in the case of PVC essentially requiring addition of a plasticizer in terms of manufacturing processes or uses thereof, it is possible to avoid use of the plasticizer which has recently become susceptible to control and regulation associated with use thereof due to possible generation of carcinogenic substances, by preparing PVC in the form of the above blending or composite material. However, application examples as mentioned above are only illustrative and therefore it should be understood that more and broader application examples are possible and are all encompassed within the scope of the present invention.
[0030] Representative examples of uses to which the shape-memory poly(3HB-co-3HV) block copolymer can be applied may include medical materials, materials for living necessaries, fiber/fabric materials, industrial materials and the like. In addition to shape-memory effects, the poly(3HB-co-3HV) block copolymer also possesses biodegradability, biocompatibility and superior mechanical properties, and can thus be particularly preferably used as medical materials.
[0031] The medical materials may include, but are not limited to, for example angioplasty stents, implant tubes for the urethrae and the esophagi, devices for vascular anastomosis, dental implants, and orthodontic springs or wires.
[0032] The materials for living necessaries may include, but are not limited to, for example cosmetics, massage packs, shape memory matrices, packaging materials or packaging films, and contraceptive devices.
[0033] The fiber/fabric materials may include, but are not limited to, for example brassiere wires, and functional garments having water repellent or waterproof properties.
[0034] The industrial materials may include, but are not limited to, for example fastening members, automatic switching devices, temperature-sensitive sensors, and power conversion equipment.
[0035] However, the above-mentioned examples of application are only illustrative, and therefore a variety of other uses can be considered. In addition, such uses are not particularly limited so long as shape memory effects of PHA are utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0037] FIG. 1 is a view of morphological changes showing rubber-elasticity and shape-memory effects of a PHBV film prepared in Example 2 of the present invention;
[0038] FIGS. 2 a to 2 d are photographs showing a shape (b) in which a PHBV strip (a) prepared in Example 2 of the present invention is permanently deformed into a coil-shape, a shape (c) in which the coil-shape of the PHBV strip is stretched and temporarily shaped, and a shape (d) in which the PHBV strip having a temporarily shape is heated and recovered to its original coil-shape, respectively;
[0039] FIG. 3 is a view showing construction of a plasmid in Example 3 of the present invention;
[0040] FIG. 4 is a restriction map of a phb locus (gene for biosynthesis of a short-chain-length PHA) in Pseudomonas sp. HJ-2 in Example 3 of the present invention; and
[0041] FIGS. 5 and 6 are amino acid sequences of a phb locus (gene for biosynthesis of short-chain-length PHA) in Pseudomonas sp. HJ-2.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0042] Now, the present invention will be described in more detail with reference to the following examples. These examples are provided only for illustrating the present invention and should not be construed as limiting the scope and sprit of the present invention.
EXAMPLES
Example 1
Preparation of poly(3HB-co-3HV) Block Copolymer Film Having Shape Memory Effects
[0043] Poly(3HB-co-3HV) block copolymers were biosynthesized by culturing Pseudomonas sp. HJ-2 at pH 7 using heptanoic acid as a sole carbon source. The culture was crushed to extract the poly(3HB-co-3HV) block copolymers, and the crude extracts were purified with methanol and hexane. Upon analyzing the purified poly(3HB-co-3HV) block copolymers, a variety of block copolymers were obtained which contained 20 to 70 mol % of 3-hydroxyvalerate (3HV) depending upon experimental conditions such as culturing conditions and the like. In addition, it was confirmed that all of the thus-obtained block copolymers exhibit similar degrees of shape memory effects.
[0044] For reference, blending between the above-mentioned block copolymers and third PHAs or polymers was also prepared. In this case, the blending also exhibited shape memory effects, although there were differences from one another to a certain degree.
[0045] 20% by weight of the thus-obtained poly(3HB-co-3HV) block copolymer (containing 35 mol % of 3-hydroxyvalerate (3HV)) was added to chloroform and poured into a Teflon dish, thereby preparing a poly(3HB-co-3HV) block copolymer film (a PHBV film) having a thickness of about 0.2 mm.
Example 2
Physical Properties of poly(3HB-co-3HV) Block Copolymer Film
[0046] In order to confirm the lowest temperature at which an existing hard segment is removed, a PHBV film obtained in Example 1 was stretched at different temperatures and held at the stretched state for about 30 seconds, followed by exposure to 90° C. For example, two water baths at 60° C. and 90° C. are consecutively prepared, and the PHBV film was stretched in the water bath at 60° C. and held for about one minute. Immediately thereafter, the stretched PHBV film was transferred to the water bath at 90° C. so as to confirm on whether the film is contracted or not. The lowest temperature at which the stretched PHBV film is not contracted upon exposure thereof to 90° C. can be determined as the lowest temperature at which the existing hard segment is removed. In repeated experiments, the PHBV films were subjected to uniaxial orientation at an elongation percentage of 600% and were held at room temperature for about one minute, thereby preparing deformed samples. The deformed samples were exposed to vapor having different temperatures and were cooled to room temperature to determine lengths thereof. The recovered samples were annealed at room temperature for about 3 minutes before they were used in subsequent repetitive experiments. 5 repeated experiments were carried out for three films, and the results thus obtained were averaged.
[0047] The experimental results showed that the PHBV films have leathery properties and returns to the form of film under various conditions, as shown in FIG. 1 . When the leathery film (I) is stretched for a short period of time, a rubber-elastic film (II) having a maximum elongation percentage of about 700% is obtained. The film (II) turns into a leathery film (III) when it is annealed at room temperature for several hours, and the leathery film (III) becomes about 10% longer than the film (I). When it is stretched again, the leathery film (III) becomes a rubber-elastic film (II). When the film (II) is subjected to repetitive stretching and releasing processes, or the film (IIA) is held in the stretched state for more than 30 seconds, an oriented leathery film (IV) is obtained. Surprisingly, upon heating the film (IV), it contracts and returns to its original state.
[0048] A permanent shape is made by melting crystallites of the polymers to a temperature higher than 95° C. and annealing the melted polymers at room temperature, thereby inducing crystallization thereof into a permanent shape. The PHBV polymers are significantly decomposed above 150° C. The polymer sample having the permanent shape corresponds to the film (I) as shown in FIG. 1 . A temporary shape is made by stretching the polymer sample to 600% and holding it at that state for more than 30 seconds. It is surmised that, during stretching and holding the sample, domains having new arrangement are formed, thereby leading to a temporary shape. The sample having the temporary shape corresponds to a film (IV) in FIG. 1 . The sample having the temporary shape recovers its original shape upon heating (see V, VI and VII of FIG. 1 ). Initial shrinkage was observed at 45° C., and shrinkage substantially stopped at about 75° C.
[0049] Referring to FIG. 2 , a sample (b) having a permanent coil-shape was prepared by winding a strip (a) into a coil-shape, heating it at 110° C. for 10 minutes, and annealing the heated coil strip at room temperature for 10 minutes. A strip (c) having a temporary shape was prepared by stretching the coil strip (b) at room temperature by hands. When the deformed strip (c) was exposed to vapor at 80° C., the temporary shape has returned to its original coil-shaped sample (d).
Example 3
Cloning of Short-Chain-Length PHA Synthetic (phb) Locus
[0050] In order to clone a short-chain-length PHA synthetic gene of Pseudomonas sp. HJ-2, short-chain-length PHA synthetic genes of strains capable of synthesizing other short-chain-length PHAs were aligned to thereby prepare primers choi3 and choi4 on the basis of conserved regions. Upon performing PCR using these primers, a 0.6-kb PCR product was obtained and then cloned into a T-vector (pGEM-SCL). A base sequence of pGEM-SCL was sequenced, and Blast X search was performed. As a result, pGEM-SCL showed 75% amino acid sequence homology with PHB synthase of Pseudomonas sp. 61-3. The 0.6-kb PCR product was DIG-labeled to use as a probe for cloning short-chain-length PHA synthase. The total genomic DNA of Pseudomonas sp. HJ-2 was extracted and cleaved with various restriction enzymes, and Southern hybridization was carried out with a DIG-labeled probe using a DIG diction kit. As a result, positive signals were respectively appeared at about 4 kb, 1.5 kb, 1.2 kb, 3.5 kb and 1.6 kb, and 0.6 kb fragments, when the genomic DNA was cleaved with respective restriction enzymes Sac I, EcoR I, Nco I, Sma I and Pst I. Among restriction enzymes used herein, Nco I and Sma I are also present in DNA which was used as the probe, and based on this fact, it was possible to plot an approximate restriction map. On the basis of the restriction map, a partial genomic library was constructed using 4-kb DNA, which was obtained by cleaving the total genomic DNA of Pseudomonas sp. HJ-2 with Sac I, and a pBluescript II KS + vector. Using colony hybridization, the partial genomic library containing a 4-kb Sac I fragment was subjected to clone screening (pBS-S53). Using restriction enzymes and PCR, it was re-confirmed that pBS-S53 is a desired positive clone. Upon analyzing base sequences of these clones, it could be seen that about 100 bp, corresponding to a C-terminal part of a synthase gene, was lacking. For the remaining parts, other synthase genes were aligned to construct primers HJ-2-PHB-N and HJ-2-PHB-C which were then subjected to PCR, thereby obtaining a 0.8-kb PCR product. The thus-obtained 0.8-kb PCR product was cloned into pDrive vector (pD-SCL). From the results of DNA sequencing of the pD-SCL clone thus obtained, it could be seen that the thus-obtained construct is a C-terminal of the PHB synthase. A restriction map of a phb locus is disclosed in FIG. 3 .
[0051] From complete interpretation of base sequences of both pBS-S53 and pD-SCL and analysis using vector NT1 (InforMax, Inc.), it could be seen that the resulting construct is a phb locus and there are three open reading frames (ORFs) (see FIG. 4 ). ORF1 is NADPH-dependent acetoacetyl-CoA reductase (PhbB HJ-2 ), and consists of 765 bp, 255 amino acids (see SEQ ID NO: 12) and exhibits 69% amino acid sequence homology with PhbB of Pseudomonas sp. 61-3. ORF2 is β-ketothiolase (PhbA HJ-2 ), and consists of 1179 bp, 393 amino acids (see SEQ ID NO: 12) and exhibits 72% amino acid sequence homology with PhbA of Pseudomonas aeruginosa. ORF3 encodes PHB synthase (PhbC HJ-2 ), and consists of 1701 bp, 567 amino acids (see SEQ ID NO: 12) and exhibits 69% amino acid sequence homology with Pseudomonas sp. 61-3. Similar to strains synthesizing other short-chain-length PHAs, genes involved in biosynthesis of the short-chain-length PHA of HJ-2 forms 1 operon (phbBAC HJ-2 ). However, this operon has a different composition than that of a representative strain containing a short-chain-length PHA synthase, Wautersia eutropha (formerly known as Ralstonia eutropha ), and has the same composition as that of Pseudomonas sp. 61-3, known to contain both short-chain-length PHA and medium-chain-length PHA synthase genes. For the amino acid sequence of the short-chain-length PHA synthetic (phb) locus of Pseudomonas sp. HJ-2, reference is made to FIGS. 5 and 6 .
[0052] Lipase box-like sequence is a highly conservative sequence of polyester synthase, and the active site residue, cysteine, located within the lipase box-like sequence, is known as the region where transesterification reaction occurs. In PhbCRe of a representative strain, W. eutropha, it was reported that cysteine, an amino acid at position 319, is known to be responsible for transesterification. In PhbC of Pseudomonas sp. HJ-2, it is believed that the 300 th amino acid residue, cysteine is a site where the transesterification reaction take places. In other PHA synthases, cysteine, aspartic acid and histidine, which form a catalytic triad, are all present as amino acids at positions 300, 459 and 489. Shine-Dalgarno (SD) sequence (AGGA box), known as the ribosome-binding site (RBS), could be found in 10-bp upstream of ATG which is an initiation codon of phbB, phbA and phbC genes.
[0053] Plasmids and PCR primers utilized in this example are summarized in Tables 1 and 2 as shown below.
[0000]
TABLE 1
Plasmids
Characteristics
pBluescript II KS +
Ap r lacPOZT7 and T3 promoter
pGEM T-easy vector
Ap r lacPOZ T7 and SP6 promoter
pDrive vector
Ap r Km r lacPOZ T7 and SP6 promoter
pGEM-SCL
0.6 kb PCR product of phbC HJ-2 in pGEM T-easy
vector
pBS-S53
3.8 kb Sac I fragment of phbC HJ-2 in pBluescript
II KS(+)
pD-SCL
0.8 kb PCR product of phbC HJ-2 in pDrive vector
pBS-SCL
pBluescript II KS(+) derivative: phbBAC HJ-2
pD-SCL
pDrive vector derivative phbC HJ-2
pBS-SD-C1
pBluescript II KS(+) derivative: phaC1 HJ-2
pBS-SD-C2
pBluescript II KS(+) derivative; phaC2 HJ-2
[0000]
TABLE 2
Oligonucleotide
Sequences
Choi3
5′-CCGCCSTGSATCAAGTAC-3′
Choi4
5′-GYTSGTGSYGTCYYCGTTCC-3′
HJ-PHB-N
5′-CACCATGCTGAGTTGCGCTCTAGC-3′
HJ-PHB-C
5′-TCADMSYTTYACRTARCGKCCTGGYGC-3′
SCL-1
5′-GATCGATACCAATCTCACCG-3′
SCL-2
5′-CAAAGCCAGTGGTTCGACGTA-3′
SCL-3
5′-CTGCTGAAACTGTTGGAGC-3′
SD-BA-N
5′-GGGGGTACCAATAAGGAGATATACATATGG
GTACTGCGAGCAATGCG-3′
BA-C
5′-CCCACTAGTTCAGCGCTCGATGGCCAGC-
3′
SD-phbC-N
5′-GGGCATATGACCCAGAAGAACAACAGCG-
3′
phbC-C
5′-CCCACTAGTTCADMSCTTYACRTAACGTCC
TGGCGCYGC-3′
INDUSTRIAL APPLICABILITY
[0054] As apparent from the above description, a PHA block copolymer having a particular composition in accordance with the present invention exhibits orientation-induced rubber-elasticity and shape memory effects with a fast shape-recovery rate, and therefore such characteristics in combination with physical properties such as biodegradability and biocompatibility unique to PHA enable application thereof to a variety of uses.
[0055] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. | Provided is a PHB block copolymer having orientation-induced rubber-elasticity and temperature-sensitive shape memory effects, comprising a plurality of 3-hydroxybutyrate (3HB) blocks as a repeating unit and a plurality of 3-hydroxyvalerate (3HV) blocks as a repeating unit, and optionally a hydroxy acid repeating group containing 6 or more carbon atoms.
The PHA block copolymer exhibits orientation-induced rubber-elasticity and shape memory effects with a fast shape-recovery rate, and therefore such characteristics in conjunction with physical properties such as biodegradability and biocompatibility unique to PHA enable application thereof to a variety of uses. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 37 U.S.C. §119(e) to U.S. Provisional Application Serial No. 60/190,640, filed Mar. 20, 2000 (Attorney Docket No.7987P).
FIELD OF THE INVENTION
[0002] The present invention relates to fabric bag-type containers for use in a non-immersion fabric care process for dry clean only fabrics. The outer shell of the bags are made from fabric such that the bags resist melting at higher temperatures than conventional non-fabric plastic bags and/or the bags are more pliable and/or supple than conventional non-fabric plastic bags and/or the bags retain more of their pliability and/or suppleness than conventional non-fabric plastic bags after being subjected to beat and/or the bags produce less noise during use than the conventional non-fabric plastic bags and/or the bags retain their shape and/or resist wrinkling during use better than the conventional non-fabric plastic bags. The bags of this invention are used in fabric care or “refreshment” processes are conducted in a hot air environment, preferably dryers, in the presence of a cleaning/refreshment composition.
BACKGROUND OF THE INVENTION
[0003] Certain delicate fabrics are not suitable for conventional in-home immersion cleaning processes. Home washing machines, which provide excellent cleaning results for the majority of fabrics used in today's society, can, under certain conditions, shrink or otherwise damage silk, linen, wool and other delicate fabrics. Consumers typically have their delicate fabric items “dry-cleaned”. Unfortunately, dry-cleaning usually involves immersing the fabrics in various hydrocarbon and halocarbon solvents that require special handling and must be reclaimed, making the process unsuitable for in-home use. Hence, dry-cleaning has traditionally been restricted to commercial establishments making it less convenient and more costly than in-home laundering processes. But, excluding cost and convenience, dry-cleaning processes remain generally superior to in-home, immersion laundering processes for the care of fine fabrics.
[0004] Attempts have been made to provide in-home dry-cleaning systems that combine the fabric cleaning and refreshing of in-home, immersion laundering processes with the fabric care benefits of dry-cleaning processes. One such in-home system for cleaning and refreshing garments comprises a substrate sheet containing various liquid or gelled cleaning agents, and a non-fabric plastic bag. The garments are placed in the bag together with the sheet, and then tumbled in a conventional clothes dryer. However, due to the properties of the non-fabric plastic bag, this in-home system is not suitable for hot or high heat dryers nor is it suitable for most conventional laundromat dryers which operate at higher temperatures than most in-home conventional dryers.
[0005] Further, conventional non-fabric plastic bags tend to lose their shape and/or become wrinkled during use in dryers.
[0006] Further yet, conventional non-fabric plastic bags are relatively rigid and/or tend to lose their pliability during use in dryers.
[0007] Still further yet, conventional non-fabric plastic bags tend to be relatively noisy during filling of the bag with garment(s) and/or during use in dryers and/or after being subjected to heat.
[0008] Accordingly, there is a need for a fabric care containment bag that is suitable for use in in-home dry-cleaning processes and/or laundromat dry-cleaning processes which resists melting at higher temperatures than conventional fabric care containment bags; namely, non-fabric plastic fabric care containment bags; a fabric care containment bag that is more pliable and/or supple than conventional non-fabric plastic fabric care containment bags; a fabric care containment bag that retains more of its pliability and/or suppleness than conventional non-fabric plastic fabric care containment bags after being subjected to heat; a fabric care containment bag that produces less noise during use than the conventional non-fabric plastic fabric care containment bags; a fabric care containment bag that retains its shape and/or resists wrinkling during use better than the conventional non-fabric plastic fabric care containment bags; and a fabric care kit comprising such a fabric care containment bag.
SUMMARY OF THE INVENTION
[0009] The present invention fulfills the needs identified above by providing a fabric bag that can be used in in-home and laundromat (commercial) dry-cleaning processes, especially when a hot or high heat dryer is used.
[0010] It has been surprisingly found that fabric bags, especially polyester bags, more preferably woven polyethylene terephthalate fabric bags provide improved performance over non-fabric plastic bags, as detailed below.
[0011] In one aspect of the present invention, a fabric containment bag that is heat resistant up to at least 230° C., preferably 240° C., more preferably 250° C. is provided.
[0012] In another aspect of the present invention, a fabric containment bag that is more pliable and/or supple than conventional non-fabric plastic fabric care containment bags is provided.
[0013] In yet another aspect of the present invention, a fabric containment bag that retains more of its pliability and/or suppleness than conventional non-fabric plastic fabric care containment bags after being subjected to heat is provided.
[0014] In still yet another aspect of the present invention, a fabric containment bag that produces less noise during use than the conventional non-fabric plastic fabric care containment bags is provided.
[0015] In still yet another aspect of the present invention, a fabric containment bag that retains its shape and/or resists wrinkling during use better than the conventional non-fabric plastic fabric care containment bags is provided.
[0016] In still yet another aspect of the present invention, a fabric care containment bag that substantially resists degradation (i.e., closure failure, fabric damage, damage to bag, such as holes, tears, seam damage, etc.) for at least 50 uses, preferably at least 75 uses, more preferably at least 100 uses.
[0017] In still yet another aspect of the present invention, a kit for cleaning and/or refreshing fabrics comprising a fabric containment bag in accordance with the present invention and a stain removing system comprising an absorbent stain receiving article and/or a stain removing composition in accordance with the present invention, and optionally instructions for using the fabric containment bag and stain removing system to clean and/or refresh a fabric article, is provided.
[0018] In still yet another aspect of the present invention, a kit for cleaning and/or refreshing fabrics comprising a fabric containment bag in accordance with the present invention and a cleaning and/or refreshing composition in accordance with the present invention and optionally instructions for using the fabric containment bag and cleaning and/or refreshing composition to clean and/or refresh a fabric article, is provided.
[0019] In still yet another aspect of the present invention, a kit for cleaning and/or refreshing a fabric article in need of cleaning and/or refreshing comprising a fabric containment bag in accordance with the present invention, and one or more absorbent articles comprising a carrier which releasably contains water and optionally non-water fabric cleaning/refreshment ingredients and instructions for using the fabric bag and one or more absorbent articles to clean and/or refresh a fabric article, the instructions comprising the following steps:
[0020] (a) place the fabric article to be cleaned and/or refreshed into the fabric bag;
[0021] (b) place one or more absorbent articles into the fabric bag;
[0022] (c) place the fabric containment bag containing the fabric article and one or more absorbent articles into an automatic clothes dryer; and
[0023] (d) operating the automatic clothes dryer such that the fabric article is cleaned and/or refreshed.
[0024] It has also now been unexpectedly discovered that certain fabric bags, specifically, those with more than two side walls, form a three dimensional interior void space when they are closed. This three dimensional void space allows the fabric bag to resist collapsing on the fabric articles that are treated within the bag. That is, the fabric bag retains its “billowed” configuration better than conventional envelope style non-fabric plastic bags. Even more surprisingly, the fabric bags of this invention, by virtue of their enhanced three dimensional configuration, tumble more efficiently in a conventional clothes dryer. Specifically, the fabric bags tend to maintain a position in the center of the tumbling drum of a clothes dryer resisting the centrifugal forces that tend to pull common envelope style non-fabric bags to the side walls of the drum where they collapse. By virtue of their design, the fabric bags of this invention tend to maintain their three dimensional shape such that the fabric articles inside the bag are free to tumble, while at the same time being in the controlled environment of a vapor venting fabric bag.
[0025] In still yet another aspect of the present invention, a vapor-venting fabric containment bag comprising:
[0026] i) an open configuration and a closed configuration;
[0027] ii) a VVE rating of at least about 40, preferably at least about 60 and less than about 90, preferably less than about 80, as measured in the Vapor Venting Ev Evaluation Test is provided.
[0028] When the bag is in its closed configuration the bag comprises at least three flexible side walls. Further, when the bag is in its closed configuration a three dimensional interior void space is formed whereby the bag resists collapsing. Preferably, the bag comprises at least four side walls configured in the form of a tetrahedron. In another aspect, the bag comprises at least six side walls configured in the form of a cube.
[0029] In still yet another aspect of this invention there is provided a process for cleaning or refreshing fabrics by contacting the fabrics with a fabric cleaning/refreshment composition comprising water in a vapor-venting fabric containment bag as described above. In one preferred embodiment, the process is carried out in a hot air clothes dryer at a temperature from about 40° C. to about 240° C., whereby malodors present on the fabrics are vented from the bag by means of the vapor-venting closure.
[0030] There is also provided herein a kit for cleaning and/or refreshing fabrics, comprising a package that contains one or more absorbent articles comprising a carrier which releasably contains water and optional non-water fabric cleaning/refreshment ingredients, and a vapor-venting fabric containment bag, and optionally a stain removing system, as described above. In a preferred embodiment, the kit further comprises from one to about ten of the absorbent articles which are disposable after a single use.
[0031] All percentages, ratios and proportions herein are by weight, unless otherwise specified. All documents cited are, in relevant part, incorporated herein by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] While this specification concludes with claims that distinctly define the present invention, it is believed that these claims can be better understood by reference to the Detailed Description Of The Invention and the drawings, wherein:
[0033] [0033]FIG. 1 is a schematic representation of a two sided envelope style fabric bag in accordance with the present invention; the bag is also shown with fold lines for optionally configuring the bag such that a six sided cube is formed as shown in FIG. 2;
[0034] [0034]FIG. 2 is a schematic representation of the fabric bag of FIG. 1 after it has been folded along the marked fold lines to form a six sided cube;
[0035] [0035]FIG. 3 is a schematic representation of the bag of FIG. 2 inside a rotating drum of a conventional clothes dryer;
[0036] [0036]FIG. 4 is a schematic representation of a two sided envelope style fabric bag in accordance with the present invention; the bag is also shown with fold lines for optionally configuring the bag such that a five sided three dimensional bag is formed as shown in FIG. 5;
[0037] [0037]FIG. 5 is a schematic representation of the bag of FIG. 4 after it has been folded along the marked fold lines to form a five sided three dimensional bag;
[0038] [0038]FIG. 6 is a schematic representation of a fabric sheet of bag material in accordance with the present invention; the fabric sheet of bag material is shown with fold lines for optionally configuring the fabric sheet of bag material such that a four sided three dimensional bag is formed as shown in FIG. 7;
[0039] [0039]FIG. 7 is a schematic representation of the sheet of FIG. 6 after it has been folded along the marked fold lines to form a four sided three dimensional bag;
[0040] [0040]FIG. 8 is a schematic representation of a two sided envelope style fabric bag in accordance with the present invention; the bag is shown with fold lines for optionally configuring the bag such that a four sided three dimensional bag is formed as shown in FIG. 9;
[0041] [0041]FIG. 9 is a schematic representation of the bag of FIG. 8 after it has been folded along the marked fold lines to form a four sided three dimensional bag;
[0042] [0042]FIG. 10 is a schematic representation of a fabric sheet of bag material in accordance with the present invention; the fabric sheet of bag material is shown with fold lines for optionally configuring the fabric sheet of bag material such that a cylinder is formed as shown in FIG. 11;
[0043] [0043]FIG. 11 is a schematic representation of the fabric sheet of FIG. 10 after it has been formed into a cylinder; and
[0044] [0044]FIG. 12 is a schematic representation of the cylinder of FIG. 11 and ultimately the fabric sheet of FIG. 10 after it has been folded along the marked fold lines to form a four sided three dimensional bag.
[0045] [0045]FIG. 13 is a schematic representation of a two sided envelope style fabric bag in accordance with the present invention; the bag is shown with fold lines for optionally configuring the fabric bag such that a four sided three dimensional bag is formed as shown in FIG. 14;
[0046] [0046]FIG. 14 is a schematic representation of the bag of FIG. 13 after it has been folded along the marked fold lines to form a four sided three dimensional bag.
DETAILED DESCRIPTION OF THE INVENTION
[0047] It will be appreciated from the disclosures herein that the present invention provides the user with a fabric bag, preferably a woven fabric bag, more preferably a woven polyester fabric bag, most preferably a vapor venting fabric containment bag and/or a three dimensional fabric bag, that can be used for cleaning and refreshing fabrics, especially garments, in a simple, readily available apparatus such as a conventional hot air clothes dryer. The fabric bags and processes of the invention can be used with any type of fabric/garment, including “Dry Clean Only” (DCO) garments. In a preferred embodiment, the user is provided with an article which comprises an absorbent core which releasably contains a cleaning/refreshment composition. In one embodiment, this core with its load of liquid composition is substantially enrobed in an outer cover sheet, which has openings through which the composition is permeable in the vapor state, but which constitutes a barrier through which liquid can flow in, but would be somewhat restrained in the core against flow outward. The liquid-loaded core can also be enrobed in low-density non-water absorbent fabric or non-fabric sheet comprising fibers such as nylon, polyester, polypropylene and the like. In addition, the user can, optionally, also be provided with a separate portion of a spot removal (“pre-spotting”) composition.
[0048] When treating a fabric (such as a soiled, wrinkled or malodorous garment) in the present manner, the item is first inspected for heavily spotted areas. If none are found, the item being treated is placed in the fabric bag of this invention together with the cleaning/refreshment article herein and tumbled in a hot air clothes dryer in the manner disclosed, i.e., the “in-dryer” step.
[0049] If heavily spotted areas are found, it is preferred to treat them individually before the in-dryer step. The pre-spotting steps of this invention are discussed in detail below.
[0050] Containment Bag
[0051] It has now been discovered that high water content compositions can be loaded onto a carrier substrate such as a cloth or fabric or non-fabric towelette and placed in a bag environment in a heated operating clothes dryer, or the like, to remove malodors from fabrics as a dry cleaning alternative or “fabric refreshment” process. The warm, humid environment created inside this bag volatilizes malodor components in the manner of a “steam distillation” process, and moistens fabrics and the soils thereon. This moistening of fabrics can loosen pre-set wrinkles, but overly wet fabrics can experience setting of new wrinkles during the drying stage toward the end of the dryer cycle. Proper selection of the amount of water used in the process and, importantly and preferably, proper venting of the bag in the present manner can minimize wrinkling. Moreover, venting of the bag permits any volatilized malodorous materials removed from the fabrics to be removed from the bag thus preventing undesirable re-depositing onto the fabrics.
[0052] The preferred design of the venting ability of the bag achieves a proper balance of the above effects. A tightly-sealed, vapor impermeable “closed” bag will not purge malodors and will overly moisten the fabrics, resulting in wrinkling. An overly “open” bag design will not sufficiently moisten the fabrics or soils to mobilize heavier matodors or to remove pre-existing fabric wrinkles. Further, the bag must be “closed” enough to billow and create a void volume under water vapor pressure, wherein the fabrics can tumble freely within the bag and be exposed to the vapors. By allowing the fabric articles to tumble freely, wrinkle removal is improved and wrinkle resistance/prevention is enhanced.
[0053] Preferably the bag must be designed with sufficient venting to trap a portion of water vapors (especially early in the dryer cycle) but to allow most of the water to escape by the end of the cycle. Said another way, the rate of vapor release is, preferably, optimized to secure a balance of vapor venting and vapor trapping. A preferred bag design employs a water vapor impermeable fabric, preferably a fabric plastic fabric, more preferably a fabric polyethylene terephthalate fabric, with a closure, preferably a zipper, but other closures such as a closure flap like that of a large envelope that employs a hook-and-loop VELCRO®-type fastener can be used.
[0054] The fabrics, when removed from the bag, will usually contain a certain amount of moisture. This will vary by fabric type. For example, silk treated in the optimal range shown on the graph may contain from about 0.5% to about 2.5%, by weight, of moisture. Wool may contain from up to about 4%, by weight, of moisture. Rayon also may contain up to about 4% moisture. This is not to say that the fabrics are, necessarily, frankly “damp” to the touch. Rather, the fabrics may feel cool, or cool-damp due to evaporative water losses. The fabrics thus secured may be hung to further air dry, thereby preventing wrinkles from being re-established. The fabrics can be ironed or subjected to other finishing processes, according to the desires of the user.
[0055] The present invention thus provides fabric bags, and in a preferred embodiment three dimensional vapor-venting fabric containment bags which are intended for use in fabric cleaning/refreshment operations. The bags are preferably designed for multiple uses and reuses, preferably at least 50 uses, more preferably at least 75 uses and most preferably at least 100 uses, and are especially adapted for use by the consumer in any conventional hot air clothes dryer apparatus, such as those found in the home or in commercial laundry/cleaning establishments. The bags herein are preferably designed to vent water and other vapors which emanate from within the bag when used in the manner described herein. The vapors released from the bag are exhausted through the air vent of the dryer apparatus.
[0056] The bag herein is most preferably formed from fabric which is heat resistant up to at least about 204° C.-260° C., preferably up to about 230° C., more preferably up to about 240° C. and most preferably up to about 250° C. Polyethylene terephthalate is a preferred fabric for forming the bag. Other suitable materials known to those of ordinary skill in the art can also be used for the fabric, such as fabric nylon.
[0057] As described more fully below, the preferred fabric bags are provided with a vapor-venting closure which provides one or more gaps through which vapors are released from the bag, in-use. For example, if the closure is a zipper, preferably the material, such as fabric attached to the teeth of the zipper allows for sufficient vapor venting of the bag. In a preferred embodiment, the type of closure and material comprising the closure preferably is chosen to permit sufficient vapor venting of the bag in accordance with the present invention. The closure preferably is selected to provide controlled vapor release from the bag under the indicated operating conditions.
[0058] Alternatively, the bag can be provided with a series of holes or other fenestrations which provide vapor venting. However, such venting is not as effective as the vapor-venting closure.
[0059] In another embodiment, the edge of one wall of the bag is notched along a substantial portion of its width to facilitate and optimize vapor venting.
[0060] In one embodiment, the present invention comprises a fabric bag, preferably a vapor-venting fabric containment bag comprising an open end, a closed end and at least three flexible side walls having inner and outer surfaces, the open end of the bag having a closure, preferably a zipper-like closure.
[0061] In yet another embodiment, the present invention encompasses a fabric bag, preferably a vapor-venting fabric containment bag comprising an open end, a closed end and at least three flexible side walls having inner and outer surfaces, the open end of the bag having a section of one side wall extending beyond the open end to provide a flexible flap, the flap having first fastening device affixed thereto, the flap being foldable to extend over a portion of the outside surface of the opposing side wall, the flap being affixable to the outer surface of the opposing wall of the bag by engaging the first fastening device on the inside face of the flap with a second fastening device present on the outside face of the opposing side wall, the first and second fastening devices, when thus engaged, forming a fastener, thereby providing a closure for the open end of the bag. The first and second fastening devices are disposed so as, when engaged, to provide vapor-venting along the closure, especially at the lateral edges of the closure. The first and second fastening devices can form a mechanical fastener or an adhesive fastener.
[0062] In an alternate mode, the flap can be folded to provide the closure, tucked inside the opposing side wall, and secured there by a fastener. In this mode, vapors are vented along the closure and especially at the lateral edges of the closure. In yet another mode, the side walls are of the same size and no flap is provided. Fastening devices placed intermittently along portions of the inner surfaces of the side walls are engaged when the lips of the side walls are pressed together to provide closure. One or more vapor-venting gaps are formed in those regions of the closure where no fastening device is present.
[0063] While the fastening devices herein can comprise chemical adhesives, the bag is preferably designed for multiple uses. Accordingly, reusable mechanical fasteners are preferred for use herein. Any reusable mechanical fastener or fastening means can be used, as long as the elements of the fastener can be arranged so that, when the bag is closed and the fastener is engaged, a vapor-venting closure is provided. Non-limiting examples include: bags wherein the first and second fastening devices, together, comprise a hook and loop (VELCRO®-type) fastener; hook fasteners such as described in U.S. Pat. No. 5,058,247 to Thomas & Blaney issued Oct. 22, 1991; bags wherein the first and second fastening devices, together, comprise a hook and string type fastener; bags wherein the first and second fastener devices, together, comprise an adhesive fastener; bags wherein the first and second fastening devices, together, comprise a toggle-type fastener; bags wherein the first and second fastening devices, together, form a snap-type fastener; as well as hook and eye fasteners, ZIP LOK®-style fasteners, zipper-type fasteners, and the like, so long as the fasteners are situated so that vapor venting is achieved. Other fasteners can be employed, so long as the vapor-venting is maintained when the bag is closed, and the fastener is sufficiently robust that the flap does not open as the bag and its contents are being tumbled in the clothes dryer. The fastening devices can be situated that the multiple vapor-venting gaps are formed along the closure, or at the lateral edges, or so that the gap is offset to one end of the closure.
[0064] Turning now to the drawings wherein FIG. 1 is a schematic representation of a two sided envelope style fabric bag 10 . The bag 10 is shown with fold lines inscribed thereon for optionally configuring the bag 10 such that a six sided cube is formed as described below and as shown in FIG. 2. Letters A-P have been used to indicate fold lines and intersection points on side wall 12 of bag 10 . The points on the opposite side wall 14 of envelope bag 10 , which correspond to the interior points M, N, O and P are labeled M′, N′, O′ and P′, respectively. Envelope bag 10 is sealed and/or sewn along edges ALKJ, ABCD and DEFG. Edges JIHG and JI′H′G are a part of side walls 12 and 14 , respectively, and these edges define bag opening 13 .
[0065] When bag 10 is folded along the lines shown (for example, lines LMNE, AM, and CNOH) a six sided cube is formed as shown in FIG. 2 as bag 11 . It is highly preferred that the edge lines MM′, NN′, OO′ and PP′ be sealed and/or sewn, for example either mechanically or adhesively so that the bag maintains its cube-like configuration. The triangular shaped tips (for example, AMM′ and JPP′) can be removed or they can be folded against one of the side walls. Alternatively, the triangular shaped tips can be left sticking out to help bag 11 align within the rotary drum of a conventional dryer as shown in FIG. 3.
[0066] Specifically, FIG. 3 shows a six sided bag 11 according to this invention inside of a rotary drum 20 of a conventional clothes dryer (not shown). While not wanting to be bound by any one theory, it is believed that bag 11 and rotary drum 20 both rotate about axis 22 as illustrated by arrow 24 . This is in sharp contrast to a conventional envelope style bag which is believed to by drawn to the side walls of the rotary drum by centrifugal forces created as the drum spins about its axis. Once pressed against the side of the drum, an envelope style bag is prone to collapsing. This in turn restricts the interior space of the bag within which the fabric articles have to tumble. As discussed above, a collapsed bag provides sub-optimal cleaning and refreshing for fabric articles.
[0067] [0067]FIG. 4 is a schematic representation of a two sided envelope style fabric bag 30 . The bag 30 is shown with fold lines inscribed thereon for optionally configuring the bag 30 such that a five sided three dimensional bag if formed and described below and as shown in FIG. 5. Letters A-J have been used to indicate fold lines and intersection points on side wall 32 of bag 30 . The points on the opposite side wall 34 of envelope bag 30 , which correspond to the interior points I and J are labeled I′ and J′, respectively. Envelope bag 30 is sealed and/or sewn along edges ABC, CDEF and FGH. There are two edges AH, which are part of side walls 32 and 34 , respectively, and these edges define bag opening 33 .
[0068] When bag 30 is folded along the lines shown (for example, lines AID and Cl) a five sided bag 31 is formed as shown in FIG. 5. It is highly preferred that the edge lines II′ and JJ′ be sealed and/or sewn, for example, either mechanically or adhesively, so that the bag maintains its three dimensional configuration. The triangular shaped tips (CII′ and FJJ′) can be removed as shown or they can be folded against one of the side walls. Alternatively, the triangular shaped tips can be left sticking out to help the bag align within the rotary drum of a conventional dryer.
[0069] [0069]FIG. 6 is a schematic representation of a fabric sheet 40 of bag material. The fabric sheet 40 of bag material is shown with fold lines inscribed thereon for optionally configuring the fabric sheet 40 such that a four sided three dimensional bag is formed as described below and as shown in FIG. 7. Letters A-F have been used to indicate fold lines and intersection points on sheet 40 . Sheet 40 is folded along lines DB, BE and EC, then edges ED and EF are sealed and/or sewn together, and edges AD and CF are sealed and/or sewn together to form a tetrahedral bag 42 , as shown in FIG. 7. Edges BC and BA define bag opening 43 , as shown in FIG. 7.
[0070] [0070]FIG. 8 is a schematic representation of a two sided envelope style fabric bag 50 . The fabric bag 50 is shown with fold lines inscribed thereon for optionally configuring the fabric bag 50 such that a four sided three dimensional bag is formed as described below and as shown in FIG. 9. Letters A-F have been used to indicate fold lines and intersection points on side walls 52 and 54 of bag 50 . The fold lines present on side wall 52 are EC and ED. Analogous fold lines are present on side wall 54 ; namely, F-C and F-D. Bag 50 is sealed and/or sewn along edges AD, DC and BC. There are two edges AEB and AFB, which are part of side walls 52 and 54 , respectively, and these edges define bag opening 53 . When bag 50 is folded along the lines shown (for example, lines ED and EF) a tetrahedral bag 51 is formed as shown in FIG. 9.
[0071] [0071]FIG. 10 is a schematic representation of a fabric sheet 60 of bag material. The fabric sheet 60 of bag material is shown with fold lines inscribed thereon for optionally configuring the fabric sheet 60 such that a cylinder is formed as described below and as shown in FIG. 11. Letters A-G, C′, E′, F′, and G′ have been used to indicate fold lines and intersection points on sheet 60 . Letter D′ has been used to indicate a mid-point on edge F′G′.
[0072] As shown in FIG. 11, the fabric sheet 60 can be formed into a cylinder shape 61 by contacting and preferably sealing and/or sewing fold line EE′ to fold line CC′ such that a fold line between point CE and C′E′ is formed.
[0073] An example of one method for forming the tetrahedral fabric bag 62 , as shown in FIG. 12, is by forming the cylinder 61 , as shown in FIG. 11. The cylinder 61 comprises a first opening 63 and a second opening 64 . The second opening 64 is closed by sealing and/or sewing along seal line DC-E. After forming seal DC-E, the cylinder 61 is stretched along stretch line BA such that point D′ and C′-E′ about come in contact with each other, such that the bag opening 63 ′ of the tetrahedral fabric bag 62 is formed by edges BC′-E′A and BD′A. This method substantially produces the tetrahedral fabric bag 62 , as shown in FIG. 12.
[0074] Another example of a method for forming the tetrahedral fabric bag 62 , as shown in FIG. 12, is by folding the fabric sheet 60 along fold lines CA, AD, DB, BE, then fold lines CC′ and EE′ are sealed and/or sewn together and fold lines CD and DE are sealed and/or sewn together to form the tetrahedral fabric bag 62 . Edges BC′-E′A and BD′A define bag opening 63 ′, as shown in FIG. 12.
[0075] [0075]FIG. 13 is a schematic representation of a two sided envelope style fabric bag 70 . The fabric bag 70 is shown with fold lines inscribed thereon for optionally configuring the fabric bag 70 such that a four sided three dimensional bag is formed as described below and as shown in FIG. 14. Letters A-F have been used to indicate fold lines and intersection points on side walls 72 and 74 of bag 70 . The fold lines present on side wall 72 are EC and ED. Analogous fold lines are present on side wall 74 ; namely, FC and FD. Bag 70 is sealed and/or sewn along edges AD, DC and BC. There are two edges AEB and AFB, which are part of side walls 72 and 74 , respectively, and these edges define bag opening 73 . When bag 70 is folded along the lines shown (for example, lines ED and EC) a tetrahedral fabric bag 71 is formed as shown in FIG. 14. Another method for forming the tetrahedral fabric bag 71 shown in FIG. 14 is closing a closure, such as a zipper, from E to F or F to E. By closing such a closure between EF, the fabric bag 70 automatic configures itself into the tetrahedral fabric bag 71 as shown in FIG. 14.
[0076] The construction of the preferred, heat-resistant vapor-venting bags used herein to contain the fabrics in a hot air laundry dryer or similar device preferably employs thermal resistant films to provide the needed temperature resistance to internal self-sealing and external surface deformation sometimes caused by overheated clothes dryers. In addition, the bags are resistant to the chemical agents used in the cleaning or refreshment compositions herein. By proper selection of bag material, unacceptable results such as bag melting, melted holes in bags, and sealing of bag wall-to-wall are avoided. In a preferred mode, the fastener is also constructed of a thermal resistant material. The method of assembling the bags can be varied, depending on the equipment available to the manufacturer and is not critical to the practice of the invention.
[0077] The dimensions of the containment bag can vary, depending on the intended end-use. For example, a relatively smaller bag can be provided which is sufficient to contain one or two silk blouses. Alternatively, a larger bag suitable for handling a man's suit can be provided. Typically, the bags herein will have an internal volume of from about 10,000 cm 3 to about 25,000 cm 3 . Bags in this size range are sufficient to accommodate a reasonable load of fabrics (e.g., 0.2-5 kg) without being so large as to block dryer vents in most U.S.-style home dryers. Somewhat smaller bags may be used in relatively smaller European and Japanese dryers.
[0078] The bags herein are preferably flexible, yet are preferably durable enough to withstand multiple uses. The bags also preferably have sufficient stiffness that they can billow, in-use, thereby allowing its contents to tumble freely within the bag during use.
[0079] The inner surface or parts thereof of the fabric bag of the present invention preferably comprises a moisture barrier that inhibits the drying of the fabrics such that the fabrics do not become too dry before the operation is complete. Preferred moisture barriers include inner coating layers, preferably made of plastic, more preferably selected from the group consisting of polybutylene terephthalate, polypropylene, nylon and mixtures thereof. The moisture barrier is preferably made from a material that resists melting up to at least about 155° C., more preferably up to about 180° C., even more preferably up to about 195° C., most preferably up to about 209° C. This inner coating layer is preferably extruded onto the inner surface or parts thereof of the fabric bag. Nonlimiting examples of coating processes include extrusion coating of the fabric components of the fabric bag; knife-coating of the fabric components of the fabric bag; adhesive-laminating of the coating to the fabric components of the fabric bag. Without being bound by theory, it is believed that this inner coating layer functions as a moisture barrier to prevent the fabrics contained within the fabric bag from over-drying during use.
[0080] Process for Making Bag
[0081] The fabric bags and/or fabrics making up the fabric bags of the present invention can be made by any suitable process, especially textile processes such as conducted in textile mills, known to those of ordinary skill in the art. Preferably, the fabrics are woven from polyester fibers, preferably 150 denier plain weave fibers. Nonliminiting examples of such fibers are commercially available from DUPONT under the trade name DACRON®.
[0082] Vapor Venting Evaluation
[0083] A preferred containment bag in accordance with the present invention is a vapor-venting containment bag. In its broadest sense, the preferred vapor-venting containment bag used in this invention is designed to be able to vent at least about 40%, preferably at least about 60%, up to about 90%, preferably no more than about 80%, by weight, of the total moisture introduced into the bag within the operating cycle of the clothes dryer or other hot air apparatus as measured according to the Vapor-Venting Evaluation Test described herein. (Of course most, if not all, of organic cleaning solvents, if any, will also be vented during use together with the water. However, since water comprises by far the major portion of the cleaning/refreshment compositions herein, it is more convenient to measure and report the venting as water vapor venting.)
[0084] It will be appreciated by those knowledgeable about the operation of hot air clothes dryers and similar apparatus that the rate of venting will usually not be constant over the entire operating cycle. All dryers have a warm-up period at the beginning of the operating cycle, and this can vary according to the specifications of the manufacturer. Most dryers have a cool-down period at the end of the operating cycle. Some venting from the containment bag can occur during these warm-up and cool-down periods, but its rate is generally less than the venting rate over the main period of the drying cycle. Moreover, even during the main period of the cycle, many modern dryers are constructed with thermostat settings which cause the air temperature in the dryer to be increased and decreased periodically, thereby preventing overheating. Thus, an average, rather than constant, dryer operating temperature in the target range of from about 50° C. to about 85° C. is typically achieved.
[0085] Moreover, the user of the present containment bag may choose to stop the operation of the drying apparatus before the cycle has been completed. Some users may wish to secure fabrics which are still slightly damp so that they can be readily ironed, hung up to dry, or subjected to other finishing operations.
[0086] Apart from the time period employed, the Vapor-Venting Equilibrium (“VVE”) for any given type of vapor-venting closure will depend mainly on the temperature achieved within the dryer—which, as noted above, is typically reported as an average “dryer air temperature”. In point of fact, the temperature reached within the containment bag is more significant in this respect, but can be difficult to measure with accuracy. Since the heat transmittal through the walls of the bag is rather efficient due to the thinness of the walls and the tumbling action afforded by conventional clothes dryers, it is a reasonable approximation to measure the VVE with reference to the average dryer air temperature.
[0087] Moreover, it will be appreciated that the vapor-venting from the containment bag should not be so rapid that the aqueous cleaning/refreshment composition does not have the opportunity to moisten the fabrics being treated and to mobilize and remove the soils/malodors therefrom. However, this is not of practical concern herein, inasmuch as the delivery of the composition from its carrier substrate onto the fabrics afforded by the tumbling action of the apparatus occurs at such a rate that premature loss of the composition by premature vaporization and venting is not a significant factor. Indeed, the preferred bag herein is designed to prevent such premature venting, thereby allowing the liquid and vapors of the cleaning/refreshment composition to remain within the bag for a period which is sufficiently long to perform its intended functions on the fabrics being treated.
[0088] One embodiment of a vapor-venting containment bag comprises an open end, a closed end and flexible side walls having inner and outer surfaces, the open end of said bag having a section of one side wall extending beyond said open end to provide a flexible flap, said flap having first fastening device, said flap being foldable to extend over a portion of the outside surface of the opposing side wall, said flap being affixable to the outer surface of the opposing side wall of the bag by engaging said first fastening device with a second fastening device present on said opposing side wall, thereby providing a closure for the open end of the bag, said first and second fastening devices being disposed so as, when engaged, to provide at least one vapor-venting gap along said closure.
[0089] Another such vapor-venting containment bag comprises an open end, a closed end and flexible side walls having inner and outer surfaces, the side walls being of equal length, wherein the first side wall is notched over part of its width, whereby said opposing side wall thereby extends beyond said notched portion of said first side wall, thereby providing a flexible flap, said flap being foldable over said notched portion to provide a vapor-venting gap when said bag is closed.
[0090] In another mode, there is provided a vapor-venting bag with the aforesaid VVE ratings whose side walls are fenestrated. A combination of vapor-venting closure and fenestrations can also be used to achieve the desired VVE.
[0091] In yet another embodiment, such a vapor-venting containment bag comprises open end, a closed end and flexible side walls having inner and outer surfaces, the side walls being of equal length, and a closure that substantially closes the open end, but does not completely close the open end such that sufficient vapor-venting from the bag is achieved.
[0092] In still another embodiment, such a vapor-venting containment bag comprises open end, a closed end and flexible side walls having inner and outer surfaces, the side walls being of equal length, and a closure that completely closes the open end of the bag, but the closure permits sufficient vapor-venting in accordance with the present invention.
[0093] The vapor-venting containment bag facilitates venting of malodors from the bag via the vapor-venting feature and/or providing any fabrics within the vapor-venting containment bag, wrinkle removal and/or wrinkle resistance benefits.
[0094] Thus, different from art-disclosed processes, the vapor-venting containment bag of the present invention provides, in a process for cleaning/refreshing fabrics in a mechanical apparatus by placing said fabrics in a fabric vapor-venting containment bag together with a cleaning/refreshment composition and operating said apparatus with heating, such that during venting of water vapors from said bag during said process malodors are released from the bag and fabric wrinkling is minimized. These benefits are optimally secured when the VVE rating of said bag is at least about 40. The process can be conducted in any apparatus, but is conveniently conducted with heating and tumbling in a hot air clothes dryer.
[0095] The following Vapor-Venting Evaluation Test (VVET) illustrates the foregoing points in more detail. Larger or smaller containment bags can be used, depending on the volume of the dryer drum, the size of the fabric load, and the like. As noted above, however, in each instance the containment bag is designed to achieve a degree of venting, or VVE “score”, of at least about 40% (40 VVE), preferably at least about 60% (60 VVE), up to about 90% (90 VVE).
Vapor-Venting Evaluation Test
[0096] Materials:
[0097] Fabric Bag to be evaluated for VVE.
[0098] Carrier Substrate (15″×11″; 38.1 cm×27.9 cm) HYDRASPUN® carrier substrate sheet from Dexter with (10444) or without (10244) Binder
[0099] Wool Blouse: RN77390, Style 12288, Weight approx. 224 grams
[0100] Silk Blouse: RN40787, Style 0161, Weight approx. 81 grams
[0101] Rayon Swatch: 45″×17″ (114.3 cm×43.2 cm), Weight approx. 60 grams
[0102] Pouch: 5″×6.375″ (12.7 cm×16.2 cm) to contain the Carrier Substrate and water
[0103] De-ionized Water; Weight is variable to establish VVE.
[0104] Pretreatment of Fabrics:
[0105] 1. The wool, silk, and rayon materials are placed in a Whirlpool dryer (Model LEC7646DQO) for 10 minutes at high heat setting, with the heating cycle ranging from about 140° F.-165° F. to remove moisture picked up at ambient condition.
[0106] 2. The fabrics are then removed from the dryer and placed in sealed nylon or plastic bags (minimum 3 mil. thickness) to minimize moisture pick up from the atmosphere.
[0107] Test Procedure:
[0108] 1. Water of various measured weights from 0 to about 40 grams is applied to the carrier substrate a minimum of 30 minutes before running a vented bag test. The substrate is folded, placed in a pouch and sealed.
[0109] 2. Each fabric is weighed separately and the dry weights are recorded. Weights are also recorded for the dry carrier substrate, the dry pouch containing the substrate, and the dry containment bag being evaluated.
[0110] 3. Each garment is placed in the bag being evaluated for vapor venting along with the water-containing substrate (removed from its pouch and unfolded).
[0111] 4. The bag is closed without expressing the air and placed in the Whirlpool Dryer for 30 minutes at the high heat setting, with tumbling per the standard mode of operation of the dryer.
[0112] 5. At the end of 30 minutes the bag is removed from the dryer and each fabric, the carrier substrate, the bag and the pouch are weighed for water weight gain relative to the dry state. (A possible minor loss in weight for the containment bag due to dryer heat is ignored in the calculations.)
[0113] 6. The weight gain of each garment is recorded as a percent of the total moisture applied to the carrier substrate.
[0114] 7. The remaining unmeasured moisture divided by the total moisture is recorded as percent vented from the dryer bag.
[0115] 8. When a series of total applied moisture levels are evaluated, it is seen that above about 15-20 grams of water the % vented becomes essentially constant, and this is the Vapor-Venting Equilibrium value, or VVE, for the particular bag venting design.
[0116] It can be seen from examining a series of VVET results at various initial moisture levels that the water at lower initial levels is being disproportionately captured by the garment load, the headspace, and the nylon bag, such that venting of water and volatile malodors begins in earnest only after the VVE value is achieved. Since this occurs only when about 15-20 grams or more of water is initially charged, it is seen that a VVE of greater than about 40 is needed to avoid excessive wetting of garments, leading to unacceptable wet-setting of wrinkles, as discussed herein.
[0117] Malodor and/or Wrinkle Removal
[0118] The overall process herein optionally comprises a spot removal step on isolated, heavily stained areas of the fabric. Following this localized stain removal step, the entire fabric can be cleaned/refreshed in the fabric containment bag, preferably the vapor-venting containment bag. This latter step provides a marked improvement in the overall appearance and refreshment of fabrics, especially with respect to the near absence of malodors and wrinkles, as compared with untreated fabrics.
[0119] One assessment of this step of the process using the vapor-venting fabric containment bag herein with respect to malodors comprises exposing the fabrics to be tested to an atmosphere which contains substantial amounts of cigarette smoke. In an alternate mode, or in conjunction with the smoke, the fabrics can be exposed to the chemical components of synthetic perspiration, such as the composition available from IFF, Inc. Expert olfactory panelists are then used to judge odor on any convenient scale. For example, a scale of 0 (no detectable odor) to 10 (heavy malodor) can be established and used for grading purposes. The establishment of such tests is a matter of routine, and various other protocols can be devised according to the desires of the formulator.
[0120] For example, garments to be “smoked” are hung on clothing hangers in a fume hood where air flow has been turned off and vents blocked. Six cigarettes with filters removed are lighted and set in ashtrays below the garments. The hood is closed and left until the cigarettes have about half burned. The garments are then turned 180.degree. to get even distribution of smoke on all surfaces.
[0121] Smoking is then continued until all cigarettes are consumed. The garments are then enclosed in sealed plastic bags and allowed to sit overnight.
[0122] After aging for about one day, the garments are treated in the cleaning/refreshment process using the venting bag. The garments are removed promptly from the containment bag when the dryer cycle is finished, and are graded for malodor intensity. The grading is done by an expert panel, usually two, of trained odor and perfume graders. The malodor intensity is given a grade of 0 to 10, where 10 is full initial intensity and 0 is no malodor detected. A grade of I is a trace detection of malodor, and this grade is regarded as acceptably low malodor to most users.
[0123] In the absence of perfume ingredients in the cleaning cloth composition, the grading of residual malodor intensity is a direct indication of degree of cleaning or removal of malodorous chemicals. When perfumed compositions are used, the grading panelists can also determine a score for perfume intensity and character (again on a 0 to 10 scale), and the malodor intensity grading in this case would indicate the ability of the residual perfume to cover any remaining malodorous chemicals, as well as their reduction or removal.
[0124] After the garment odor grading taken promptly after the cleaning/refreshment process, the garments are hung in an open room for one hour and graded again. This one-hour reading allows for an end-effect evaluation that would follow cool-down by the garments and drying of the moisture gained in the dryer cycle treatment. The initial out-of-bag grading does reflect damp-cloth odors and a higher intensity of warm volatiles from the bag, and these are not factors in the one-hour grades. Further garment grading can be done at 24 hours and, optionally, at selected later times, as test needs dictate.
[0125] Likewise, fabric wrinkles can be visually assessed by skilled graders. For example, silk fabric, which wrinkles rather easily, can be used to visually assess the degree of wrinkle-removal achieved by the present processes using the vapor-venting bag. Other single or multiple fabrics can optionally be used. A laboratory test is as follows.
[0126] De-Wrinkling Test
[0127] Materials:
[0128] As above for VVET.
[0129] De-ionized Water, Weight range (0-38 grams)
[0130] Pretreatment of Fabrics:
[0131] The silk fabric is placed in a hamper, basket, or drum to simulate normal conditions that are observed after wearing. These storage
[0132] conditions produce garments that are severely wrinkled (well defined creases) and require a moist environment to relax the wrinkles.
[0133] Test Procedure:
[0134] 1. One silk fabric is placed in a containment bag being tested.
[0135] 2. Water (0-38 grams) is applied to the carrier substrate a minimum of 30 minutes before running the test, placed in a pouch and sealed.
[0136] 3. The silk garment is placed in the test containment bag along with the water-containing substrate (removed from its pouch and unfolded).
[0137] 4. The bag is closed and placed in a Whirlpool Dryer (Model LEC7646DQO) for 30 minutes at high heat (48-74C cycle).
[0138] 5. At the end of 30 minutes, the dryer bag is removed from the dryer IMMEDIATELY and the silk garment is placed on a hanger.
[0139] 6. The silk garment is then visually graded versus the Control Garment from the same Pretreatment Of Fabrics.
[0140] In laboratory tests of the foregoing type, the in-dryer, non-immersion cleaning/refreshment processes herein typically provide malodor (cigarette smoke and/or perspiration) malodor grades in the 0-1 range for smoke and somewhat higher for perspiration malodors, thereby indicating good removal of malodor components other than those of sufficiently high molecular weights that they do not readily “steam vaporize” from the fabrics. Likewise, fabrics (silks) have wrinkles removed to a sufficient extent that they are judged to be reasonably suitable for wearing with little, or no, ironing.
[0141] Perfume—As noted above, various treatment agents can be applied to the fabrics during the present process. One type of agent comprises various perfume materials. However, the perfumer should select at least some perfume chemicals which are sufficiently high boiling that they are not entirely vented from the bag along with the water vapors during the drying process herein.
[0142] A wide variety of aldehydes, ketones, esters, acetals, and the like, perfumery chemicals which have boiling points above about 50.degree. C., preferably above about 85.degree. C., are known. Such ingredients can be delivered by the process herein and caused to permeate the garments of the containment bag during the processes herein. Non-limiting examples of perfume materials with relatively high boiling components include various essential oils, resinoids, and resins from a variety of sources including but not limited to orange oil, lemon oil, patchouli, Peru balsam, Olibanum resinoid, styrax, labdanum resin, nutmeg, cassia oil, benzoin resin, coriander, lavandin and lavender. Still other perfume chemicals include phenyl ethyl alcohol, terpineol and mixed pine oil terpenes, linalool, linalyl acetate, geraniol, nerol, 2-(1,1-dimethylethyl)-cyclohexanol acetate, orange terpenes and eugenol. Of course, lower boiling materials can be included, with the understanding that some loss will occur due to venting.
[0143] Cleaning And Refreshing Processes
[0144] As discussed briefly above, the cleaning and refreshing processes of this invention include the following steps. The cleaning/refreshment composition is loaded on the substrate which is preferably encased in a coversheet, and the substrate is placed in a bag according to this invention with the fabrics to be treated. The bag is closed and placed in a heated operating clothes dryer, or the like, to remove malodors from the fabrics.
[0145] In more detail, the cleaning and refreshing process herein can be conducted in the following manner. Modifications of the process can be practiced without departing from the spirit and scope of the present invention.
[0146] (i) optionally, conducting a pre-spotting process according to the description below, on localized stained areas of the fabric;
[0147] (ii) placing the entire fabric together with the substrate that releasably contains a cleaning/refreshment composition in a fabric containment bag in accordance with the present invention;
[0148] (iii) placing the bag in a device to provide agitation, e.g., such as in a hot air clothes dryer and operating the dryer with heat and tumbling to moisten the fabric; and
[0149] (iv) removing the fabric from the bag.
[0150] (v) promptly hanging the fabrics to complete drying and/or to prevent re-wrinkling.
[0151] More specifically, the cleaning and refreshment process is conveniently conducted in a tumbling apparatus, preferably in the presence of heat. The substrate containing the releasably absorbed shrinkage reducing composition and cleaning/refreshment composition is placed along with the fabrics to be treated in a nylon or other heat-resistant, and preferably vapor-venting bag. The bag is closed and placed in the drum of an automatic hot air clothes dryer at temperatures of 40° C.-150° C. The drum is allowed to revolve, which imparts a tumbling action to the bag and agitation of its contents concurrently with the tumbling. The tumbling and heating are carried out for a period of at least about 10 minutes, typically from about 20 minutes to about 60 minutes. This step can be conducted for longer or shorter periods, depending on such factors as the degree and type of soiling of the fabrics, the nature of the soils, the nature of the fabrics, the fabric load, the amount of heat applied, and the like, according to the needs of the user.
[0152] In more detail, a pre-spotting process can be conducted in the following manner. Modifications of the process can be practiced without departing from the spirit and scope of the present invention.
[0153] 1. Place a stained area of the fabric over and in contact with the absorbent stain receiving article, preferably a poly-HIPE or TBAL stain receiver described herein or, less preferably, an ordinary folded paper towel (e.g., preferably white or non-printed—to avoid dye transfer from the towel—BOUNTY® brand) on any suitable surface such as a table top, in a tray, etc.
[0154] 2. Apply enough spot cleaning composition from a dispenser bottle with a narrow spout which directs the composition onto the stain (without unnecessarily saturating the surrounding area of the fabric) to saturate the localized stained area—about 10 drops; more may be used for a larger stain.
[0155] 3. Optionally, let the composition penetrate the stain for 3-5 minutes.
[0156] 4. Optionally, apply additional composition—about 10 drops; more may be used for larger stains.
[0157] 5. Use the treatment member, such as the distal tip on the dispenser bottle to work the stain completely out. Contact can be maintained for a period of 1-60 seconds for lighter stains and 1-5 minutes, or longer, for heavier or more persistent stains.
[0158] 6. Optionally, blot the fabric, e.g., between paper towels, to remove excess composition. Or, the treated area can be blotted with a dampened sponge or other absorbent medium to flush the fibers and remove excess composition.
[0159] Cleaning/Refreshment Composition
[0160] The cleaning/refreshment composition preferably comprises water and a member selected from the group consisting of surfactants, perfumes, preservatives, bleaches, auxiliary cleaning agents, organic solvents and mixtures thereof. The preferred organic solvents are glycol ethers, specifically, methoxy propoxy propanol, ethoxy propoxy propanol, propoxy propoxy propanol, butoxy propoxy propanol, butoxy propanol and mixtures thereof. The surfactant is preferably a nonionic surfactant, such as an ethoxylated alcohol or ethoxylated alkyl phenol, and is present at up to about 2%, by weight of the cleaning/refreshment composition. Typical fabric cleaning refreshment/compositions herein can comprise at least about 80%, by weight, water, preferably at least about 90%, and more preferably at least about 95% water.
[0161] The Examples below give specific ranges for the individual components of preferred cleaning/refreshment compositions for use herein. A more detailed description of the individual components of the cleaning/refreshment compositions, that is, the organic solvents, surfactants, perfumes, preservatives, bleaches and auxiliary cleaning agents can be found in U.S. Pat. No. 5,789,368, which issued on Aug. 4, 1998 to You et al. and in U.S. Pat. No. 5,591,236, which issued on Jan. 7, 1997 to Roetker. The entire disclosure of the You et al. and the Roetker patents are incorporated herein by reference. Additionally, cleaning/refreshment compositions are described in co-pending U.S. patent application Ser. No. 08/789,171, which was filed on Jan. 24, 1997, in the name of Trinh et al. The entire disclosure of the Trinh et al. Application is incorporated herein by reference.
[0162] It is especially preferred that the cleaning/refreshment compositions of this invention include a shrinkage reducing composition, which is preferably selected from the group consisting of ethylene glycol, all isomers of propanediol, butanediol, pentanediol, hexanediol and mixtures thereof, and more preferably selected from the group consisting of neopentyl glycol, polyethylene glycol, 1,2-propanediol, 1,3-butanediol, 1-octanol and mixtures thereof. The shrinkage reducing composition is preferably neopentyl glycol or 1,2-propanediol, and is more preferably 1,2-propanediol. The ratio of shrinkage reducing composition to cleaning/refreshment composition is preferably from about 1:2 to about 1:5, preferably from about 1:2 to about 1:4, more preferably from about 1:3 to about 1:4, and most preferably about 1:3.6.
[0163] In addition to the above ingredients, the cleaning/refreshment composition may optionally comprise a bleaching agent, preferably hydrogen peroxide.
[0164] Substrate
[0165] When used in the in-dryer step of the present process, the cleaning/refreshment composition is releasably absorbed an absorbent substrate, herein after referred to as a “substrate”. The substrate releasably contains the composition. By “releasably contains” means that the composition is effectively released from the substrate onto the soiled fabrics as part of the non-immersion cleaning and fabric refreshment processes herein. This release occurs mainly by volatilization of the composition from the substrate through the vapor-permeable coversheet, or by a combination of vapor and liquid transfer, although bulk liquid transfer is desirably minimized by means of the coversheet herein.
[0166] The substrate can be in any desired form, such as powders, flakes, shreds, and the like. However, it is highly preferred that the substrate be in the form of an integral pad or “sheet” that substantially maintains its structural integrity throughout the process. The substrates and sheets of this invention are sometimes referred to in the literature as “carriers” or “absorbent carrier sheets”; it is understood that all of these labels refer to liquid absorbing materials that can be used to conveniently transport liquids. Such substrates are described in detail in U.S. Pat. No. 5,789,368, to You et al. which was incorporated herein by reference above. The manufacture of these sheets forms no part of this invention and is already disclosed in the literature. See, for example, U.S. Pat. No. 5,009,747, Viazmensky, et al., Apr. 23, 1991 and U.S. Pat. No. 5,292,581, Viazmensky, et al., Mar. 8, 1994, which are incorporated herein by reference.
[0167] A preferred substrate herein comprises a binderless (or optional low binder), hydroentangled absorbent material, especially a material which is formulated from a blend of cellulosic, rayon, polyester and optional bicomponent fibers. Such materials are available from Dexter, Non-Wovens Division, The Dexter Corporation as HYDRASPUN®, especially Grade 10244 and 10444. The manufacture of such materials forms no part of this invention and is already disclosed in the literature. See, for example, U.S. Pat. No. 5,009,747, Viazmensky, et al., Apr. 23, 1991 and U.S. Pat. No. 5,292,581, Viazmensky, et al., Mar. 8, 1994, incorporated herein by reference. Preferred materials for use herein have the following physical properties.
Grade Optional 10244 Targets Range Basis Weight gm/m 2 55 35-75 Thickness microns 355 100-1500 Density gm/cc 0.155 0.1-0.25 Dry Tensile gm/25 mm MD 1700 400-2500 CD 650 100-500 Wet Tensile gm/25 mm MD* 700 200-1250 CD* 300 100-500 Brightness % 80 60-90 Absorption Capacity % 735 400-900 H 2 O Dry Mullen gm/cm 2 1050 700-1200
[0168] As disclosed in U.S. Pat. Nos. 5,009,747 and 5,292,281, the hydroentangling process provides a nonwoven material which comprises cellulosic fibers, and preferably at least about 5% by weight of synthetic fibers, and requires less than 2% wet strength agent to achieve improved wet strength and wet toughness.
[0169] The substrate is intended to contain a sufficient amount of the cleaning/refreshment composition to be effective for the intended purpose. The capacity of the substrate for such compositions will vary according to the intended usage. The size of the substrate should not be so large as to be unhandy for the user. Typically, the dimensions of the substrate will be sufficient to provide a macroscopic surface area (both sides of the substrate) of at least about 360 cm 2 , preferably in the range from about 360 cm 2 to about 3000 cm 2 . For example, a generally rectangular substrate may have the dimensions (X-direction) of from about 10 cm to about 35 cm, and (Y-direction) of from about 18 cm to about 45 cm.
[0170] Coversheet
[0171] The coversheets employed herein are distinguished from the substrate, inasmuch as the coversheets are relatively non-absorbent to the cleaning/refreshment composition as compared with the substrate. The coversheets are constructed from hydrophobic fibers which tend not to absorb, “wick” or otherwise promote the transfer of fluids. While fluids can pass through the void spaces between the fibers of the coversheet, this occurs mainly when excessive pressure is applied to the article. Thus, under typical usage conditions the coversheet provides a physical barrier which keeps the absorbent substrate, which is damp from its load of shrinkage reducing composition and cleaning/refreshment composition, from coming into direct contact with the fabrics being treated. Yet, the coversheet does allow vapor transfer of the shrinkage reducing composition and cleaning/refreshment composition from the substrate through the coversheet and into the containment bag, and thus onto the fabrics being treated. If desired, the coversheet can be provided with macroscopic fenestrations through which the lint, fibers or particulate soils can pass, thereby further helping to entrap such foreign matter inside the article, itself.
[0172] Such fibrous, preferably heat resistant and, most preferably, hydrophobic, coversheets are described in detail in U.S. Pat. No. 5,789,368, to You et al. which was incorporated herein by reference above. Additionally, co-pending U.S. provisional application No. 60/077,556, which was filed on Mar. 11, 1998, in the name of Wise et al., describes certain improvements to the coversheets of this invention. The entire disclosure of the Wise et al. application is incorporated herein by reference. Suitable combinations of the coversheets described in You et al. with the improvements described in Wise et al. can be employed, according to the desires of the manufacturer, without departing from the spirit and scope of the invention.
[0173] Spot Cleaning Composition
[0174] The user of the present process can be provided with various spot cleaning compositions to use in the optional pre-spotting procedure of this invention. These compositions are used to remove localized stains from the fabrics being treated, either before or after the cleaning and refreshing process defined herein. Necessarily, the spot cleaning composition must be compatible with the fabric being treated. That is, no meaningful amount of dye should be removed from the fabric during the spot treatment and the spot cleaning composition should leave no visible stains on the fabric. Therefore, in a preferred aspect of this invention there are provided spot cleaning compositions which are substantially free of materials that leave visible residues on the treated fabrics. This necessarily means that the preferred compositions are formulated to contain the highest level of volatile materials possible, preferably water, typically about 95%, preferably about 97.7%, and surfactant at levels of about 0.1% to about 0.7%. A preferred spot cleaning composition will also contain a cleaning solvent such as butoxy propoxy propanol (BPP) at a low, but effective, level, typically about 1% to about 4%, preferably about 2%.
[0175] Preferred spot cleaning compositions are exemplified below, and are described in U.S. Pat. No. 5,789,368, to You et al. which was incorporated herein by reference above. Additionally, spot cleaning compositions are described in U.S. Pat. No. 5,630,847, which issued on May 20, 1997, to Roetker. The entire disclosure of the Roetker patent is incorporated herein by reference.
[0176] Treatment Member
[0177] In one embodiment, a treatment member is provided to assist in removing localized stains from fabrics. In a preferred aspect of this invention, the spot cleaning composition is provided in a dispenser, such as a bottle, and the dispenser has a distal tip that can serve as the treatment member. Additionally, the treatment member can comprise an absorbent base material which can be, for example, a natural or synthetic sponge, an absorbent cellulosic sheet or pad, or the like. In contact with and extending outward from this base material can be multiple protrusions. Specific examples of treatment members can be found in U.S. Pat. No. 5,789,368, to You et al. which was incorporated herein by reference above.
[0178] Absorbent Stain Receiving Article
[0179] An absorbent stain receiving article, sometimes referred to herein as a stain receiver, can optionally be used in the optional pre-spotting operations herein. Such stain receivers can be any absorbent material which imbibes the liquid composition used in the pre-spotting operation. Disposable paper towels, cloth towels such as BOUNTY™ brand towels, clean rags, etc., can be used. However, in a preferred mode the stain receiver is designed specifically to “wick” or “draw” the liquid compositions away from the stained area. One preferred type of stain receiver consists of a nonfabric pad, such as a thermally bonded air laid fabric (“TBAL”). Another highly preferred type of stain receiver for use herein comprises polymeric foam, wherein the polymeric foam comprises a polymerized water-in-oil emulsion, sometimes referred to as “poly-HIPE”. The manufacture of polymeric foam is very extensively described in the patent literature; see, for example: U.S. Pat. No. 5,260,345 to DesMarais, Stone, Thompson, Young, LaVon and Dyer, issued Nov. 9, 1993; U.S. Pat. No. 5,550,167 to DesMarais, issued Aug. 27, 1996, and U.S. Pat. No. 5,650,222 to DesMarais et al., issued Jul. 22, 1997, all incorporated herein by reference. Typical conditions for forming the polymeric foams of the present invention are described in co-pending U.S. patent application Ser. No. 09/042,418, filed Mar. 13, 1998 by T. A. DesMarais, et al., titled “Absorbent Materials for Distributing Aqueous Liquids”, the disclosure of which is incorporated herein by reference. Additional disclosure of conditions for forming the polymeric foams for use in the present invention are described in co-pending U.S. Provisional Patent Application Serial No. 60/077,955, filed Mar. 13, 1998 by T. A. DesMarais, et al., titled “Abrasion Resistant Polymeric Foam And Stain Receivers Made Therefrom”, the disclosure of which is incorporated herein by reference. Notwithstanding the above described preferred types of stain receivers, latex bonded air laid nonfabrics (“LBAL”) and multi-bonded air laid nonfabrics (“MBAL” combined latex and thermal bonded) stain receiver may also be used.
[0180] The various stain receivers described herein, and described in the references incorporated herein by reference, preferably comprise a liquid impermeable backsheet. The backsheet can be made of, for example, a thin layer of polypropylene, polyethylene and the like. The backsheet provides protection for the surface that the stain receiver rests on from the spot cleaning composition. For example, spot cleaning processes are typically performed on a hard surface, such as a table top. The stain receiver is placed on the table and the fabric to be treated in placed on the stain receiver. Spot cleaning composition is applied to the stained area of the fabric and then drawn into the stain receiver. But in the absence of a back sheet, the spot cleaning composition can leak onto the table top, possibly causing damage thereto.
[0181] The following Examples further illustrate the invention, but are not intended to be limiting thereof.
EXAMPLE I
Cleaning and Refreshing Compositions
[0182] Fabric cleaning/refreshment compositions according to the present invention, for use in a containment bag, are prepared as follows:
Ingredient % (wt.) Emulsifier (TWEEN 20)* 0.5 Perfume 0.5 KATHON ® 0.0003 Sodium Benzoate 0.1 Water Balance
[0183] Additionally, preferred compositions for use in the in-dryer cleaning/refreshment step of the process herein are as follows.
Ingredient % (wt.) Range (% wt.) Water 99.0 95.1-99.9 Perfume 0.5 0.05-1.5 Surfactant 0.5 0.05-2.0 Ethanol or Isopropanol 0 Optional to 4% Solvent (e.g. BPP) 0 Optional to 4%
[0184] Additionally, preferred compositions for use in the in-dryer cleaning/refreshment step of the process herein are as follows:
Ingredient % (wt.) % (wt.) % (wt.) % (wt.) Water 97.63 98.85 77.22 96.71 Perfume 0 0.38 0.38 0 Surfactant 0.285 0 0 0.285 Ethanol or Isopropanol 0 Solvent (e.g. BPP) 2.0 0 0 2.0 KATHON ® 0.0003 0 0 0 Emulsifier (TWEEN 20)* 0 0.5 0.38 0 Amine Oxide 0.0350 0 0 0.0350 MgCl 2 0.045 0 0 0 MgSO 4 0 0 0.058 0 Hydrogen Peroxide 0 0 0 0.6 Citric Acid 0 0 0 0.05 Proxel GXL 0 0.08 0.08 0 Bardac 2250 0 0.2 0.2 0 1,2-Propanediol 0 0 21.75 0
[0185] Besides the other ingredients, the foregoing compositions can contain enzymes to further enhance cleaning performance, as described in the Trinh et al. patent incorporated herein above.
EXAMPLE II
Preparation of a Substrate Comprising a Cleaning/Refreshment Composition
[0186] A 10¼ in.×14¼ in. (26 cm×36 cm) substrate in the form of a sheet is prepared from HYDRASPUN® material, manufactured by the Dexter Corp. The substrate sheet is covered on both sides with a topsheet and a bottomsheet of 8 mil (0.2 mm) Reemay fabric coversheet material. The coversheet (i.e., both topsheet and bottomsheet) are bonded to the substrate sheet by a Vertrod® or other standard heat sealer device, such as conventional sonic sealing devices, thereby bonding the laminate structure together around the entire periphery of the sheet. The edges of the sheet around its periphery are intercalated between the topsheet and bottomsheet by the bond. As noted above, the width of the bond is kept to a minimum and is about 0.25 in. (6.4 mm).
[0187] The bonded laminate sheet thus prepared is folded and placed in a pouch. Any plastic pouch which does not leak would be suitable. For example, a foil laminated pouch of the type used in the food service industry can be employed. Such pouches are well-known in the industry and are made from materials which do not absorb food flavors. In like manner, the formulator herein may wish to avoid absorption of the perfume used in the cleaning/refreshment composition by the pouch. Various pouches are useful herein and are commercially available on a routine basis.
[0188] The folded substrate/coversheet sheet is placed in the pouch. The folds can be of any type, for example, an accordion-style fold or rolled and then the roll is folded in half. This size is not critical but is convenient for placement in a pouch.
[0189] 5 grams of a shrinkage reducing composition and 18 grams of the cleaning/refreshment composition are poured onto the substrate sheet/coversheet in any order, more preferably the shrinkage reducing composition and the cleaning/refreshment composition are mixed before pouring onto the substrate. The compositions are allowed to absorb into the substrate. The pouch is sealed immediately after the liquid product is introduced into the pouch and stored until time-of-use.
EXAMPLE III
Spot Cleaning Compositions
[0190] A spot cleaning composition for use for use in the present invention, preferably with a dispenser as defined above, and with a TBAL or poly-HIPE foam stain receiver, is prepared as follows:
% (Wt.) INGREDIENT (Nonionic) Range % (Wt.) Hydrogen peroxide 1.000 0-2 Amino tris(methylene phosphonic acid)* 0.040 0-0.06 Butoxypropoxypropanol (BPP) 2.000 1-6 Neodol 23 6.5 0.250 0-1 Kathon preservative 0.0003 Optional** Water 96.710 Balance
[0191] Another example of a preferred, high water content, low residue spot cleaning composition for use in the pre-spotting step herein is as follows.
INGREDIENT Anionic Composition (%) Hydrogen peroxide 1.000 Amino tris(methylene phosphonic acid)* 0.0400 Butoxypropoxypropanol (BPP) 2.000 NH 4 Coconut E 1 S 0.285 Dodecyldimethylamine oxide 0.031 Magnesium chloride 0.018 Magnesium sulfate 0.019 Hydrotrope, perfume, other minors, 0.101 Kathon preservative 0.0003 Water (deionized or distilled) 96.507 Target pH 6.0
[0192] Preferably, to minimize the potential for dye damage as disclosed hereinabove, H 2 O 2 -containing pre-spotting compositions comprise the anionic or nonionic surfactant in an amount (by weight of composition) which is less than the amount of H 2 O 2 . Preferably, the weight ratio of surfactant:H 2 O 2 is in the range of about 1:10 to about 1:1.5, most preferably about 1:4 to about 1:3. | The present invention relates to improved bag-type containers for use in a non-immersion fabric care process for dry clean only fabrics. The outer shell of the bags are made from fabric such that the bags resist melting at higher temperatures than conventional non-fabric plastic bags and/or the bags are more pliable and/or supple than conventional non-fabric plastic bags and/or the bags retain more of their pliability and/or suppleness than conventional non-fabric plastic bags after being subjected to heat and/or the bags produce less noise during use than the conventional non-fabric plastic bags and/or the bags retain their shape and/or resist wrinkling during use better than the conventional non-fabric plastic bags. The bags of this invention are used in fabric care or “refreshment” processes are conducted in a hot air environment, preferably dryers, in the presence of a cleaning/refreshment composition. | 3 |
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